Home

Notes on Miller/Router - Technsoft

1. k E Undo Ctrl Z a jey fE ial H Redo Ctrl R ibs eP a v Line Col I Fill Col I ielect ol Copy Ctrl C E Copy as Bitmap Ctrl A Paste Ctrl V a Delete gt B Clip gt UI Select gt TZ Group Ctrl G Ungroup Ctrl U F g BC sa Unmask F fiat Make Path Al B Make Silhouette m GS Align F CLI Space Evenly Match Size ee ig Arrange gt 4 Attributes gt Property Switch Direction Normalise Text Path Conversion Edit Mode Font Grid Edit Mode Adjust Character Design Frame s Adjust Character Cellfs End Cell Width Adjustment To familiarise yourself with the commands needed to complete the exercise click and hold on the Line Arc Contour and Delete buttons on the left hand menu This will display all the options available on each Ell SELECT A Fas Draw a single line Layo oeyer I kii LIIS SLM E t Galway Education Centre 2 3 CNC Routing Delete part of an object between the neal in POEL DEL YOEL DEL DEL DEL nas ANY Cy CL Draw a closed contour The highlighted commands will be important in completing the exercise Examine each and determine how it works To edit the shape proceed as follows Switch on Attach and Radial Lock in the toolbar on the top right of the work area and construct two horizontal lines from the bottom of the letter extending beyond the outside profile These will b
2. AB Print Setup Print Offset Make PCE Ctrl M Flot Offset 1 pcb For torch dtb 2 CADESTOOLS PCETutor3 dtb 3 CHDESTOOLS PCBTutor1 dtb 4 CADESTOOLSI PCETutorz dtb Exit The window that appears next looks like its counterpart in 2 D design except that it provides some options on how the PCB is to be made Select Solder Side only and this time make sure that Full Copper Removal is checked Make PCB Plotting device Rol and MD 40 v Pens Tools Connection c ti Through printer driver Roland MDX 40 Connection Production Method l Rotated Solder side only C Component side only C Double sided board OK C Laminated board Cancel V Full Copper Removal noose Help Select Ok and a preview of the cutter path will appear This time the copper area to be machined away appears in red between the tracks sing an engraver miller cutter plotter TechSoft Design Tools PG t Galway Education Centre 43 CNC Routing Select Yes and the tool setting window will appear in the same manner as for before Tool Set Point Check Change the Tool Set Point a 5 0mm Y 5 0mm Z a Move to Tool Set Paint C Imperial O Meie Make PCB Cancel Help To set the tools choose a value of 90mm for the z tool set point and move the tool to there using the button Fit the engraving tool so that it touches the top surface of the PCB tighten the top collet and remove th
3. Font Attributes Do ps Line co E a Regular Fill Col i No fil W Fill Characters Individually F BankGothic Wd BT Drop Shadow F Batang 25 Add drop shadow Sample s p Jz 1E g ie AaBbYyZz a Ee _ pica m Effects Size spacing Fosition Characters Height 20 Oren Actual height of h Alignment i i g Align left Spacing Cancel Help Set Defaults Choose a font such as Arial or similar and make sure that the text height is set to 20mm and that Fill is turned off as shown above r t Galway Education Centre 21 CNC Routing Select Ok and then type the letter you want into the text entry box When finished you should have something similar to this The next step is to move the newly created shape into position and to edit the drawing so that it becomes part of the outside profile Drag the letter into a position close to the centre of the frame and overlapping it as shown below It may be helpful to turn Grid Lock off before moving the shape into position below right Now the profiles can be edited 22 Ot Galway Education Centre CNC Routing The Text character has all of its entities grouped and must be exploded before proceeding Highlight the character and select Edit Explode as shown 1 TechSoft Design Tools 2D Design V2 Frame TEMPLATE dtd 5 File 21 Draw Bitmaps View Setup Window Help ssaa oala x
4. Colour po Tool no i Dsm Final depth of cut 0 5mm Clearance 2 0mm Start offset 0 0mm normally 0 Cancel Help Select OK and notice that that any contours drawn in Red will be machined first followed by those in blue Change the order by editing one of the parameters say the one just created and type the required sequence in the Machining Order box Enter 1 to make Blue entities the first to be machined 48 et t Galway Education Centre CNC Routing RotoCAMM MDX 40 setup Machining parameters Output Mode Units Dda Ca Tool Final Clear Start Single tool Imperial il D nd Depth ance Offset Obits O Hie 1 0 50rmm 200mm mm Em 1 2 310mm 200mm 0 00mm Tool park Tool change je 0 0mm je 0 0mm Y 306 00 v 0 0mm Z 105 00mm Z 105 00mm Edit Remove Add draw colours Set Defaults Set Defaults Tool parameters Tool Maxdepth Tool Tool Hornz ert Spindle no perpass Dia Offset feed feed speed 71 00 200mm WA 400 200 15000 Load tools Save tools Remove OF Cancel Help This completes the tooling set up for the part The setup can be saved by clicking on the Save tools button and choosing a filename Select Ok until all windows are closed to exit the process The final job to be done is to set up the drawing area To do this proceed as follows Select Drawing Layout s D Design V2 Untitled
5. Drawing Customise tE Print Options CNC Output OFFset m Load Setup Save Setup Set 45 Default 4 SSS gt _____ 46 t Galway Education Centre The following window will then appear CNC Devices Setup Current list of CHC devices Roland MDx 40 Roland Modela MOX 15 Roland Modela MDx 20 Roland Modela MDOXx 3 Roland Stika SCP 59w75 Roland Stika STH Roland Stika 5T 8 Roland Stika S 12 Roland Stika 5W 15 narrow Roland Stika 5W 15 wide Roland Stika 5 Roland Stika 55 12 Roland Stika 5 15 narrow Roland Stika 55 15 wide Roland Stika 5 8 FRotolahh M 40 Output Route Through printer driver Roland MO 40 Use Operation Panel by default Cancel Help CNC Routing Choose the RotoCAMM MDX 40 as shown Do not press OK yet as there are other options to be set Make sure that the Output Route panel shows the Roland MDX 40 printer driver If not use the Change Driver button to make it the same as shown above Finally Tools and the following window will appear RotoCAMM MDX 40 setup Machining parameters Tool Final Order Colour Depth m Output Mode Clear Start f Single tool ance Offset Oh Mule heal 1 3 10rm 2 00rmm mm Tool park k 0 0mm ae 305 00mm Z 105 00mm m Tool change gt 0 0 mm 0 0mm 105 00mm Add Edit Eric Add draw colours Set Defaults
6. Set Defaults Tool parameters Tool Max depth Tool Tool no perpass Dia Offset 1 100mm 2 00mm M A Horiz Wert Spindle feed feed speed 200 20 0 15000 Load tools Save tools OF Cancel Help t Galway Education Centre 47 CNC Routing Setting up the tool is done in two stages First a tool is defined using the Tool parameters box at the bottom As seen above Tool No 1 is defined in the Tool Parameters panel with a diameter of 2mm Max depth per pass of 1mm and with a horizontal feedrate of 20mm s Change the federate to 40mm s by clicking on the Edit button The settings are self explanatory Tool Parameters Tool no Max Depth Per Pass mm Tool Diameter 2 0mm Horiz feed rate 40 0mm s Yvert feed rate 20 0mm s Spindle speed rpm i K000 Cancel Help lf more than one tool is being used in a program they can be defined at this stage The next stage is to set up the machining parameters for the tool The most important ones are the Depth of Cut and its associated colour Different colours are used to specify different depths of cut and several colours can be assigned to one tool The order of the machining operations is also set here In the example above one set of machining parameters is already defined and assigned to the colour red Add a second set by selecting the Add button and imputing values as shown below Machining Parameters Machining order 2
7. Y axes This is many times faster than a conventional metal cutting milling machine The machine can cut soft materials e g plastics and wood but is not suitable for cutting metal The machine is driven by a windows printer driver There is no programming language to deal with and all of the interaction with the machine is through the software running on the PC Running a job on the machine is very similar to printing a document Figure 14 TechSoft MDX 40 Router t Galway Education Centre 9 CNC Routing Operation of the Machine The machine console offers a basic set of controls that are used to switch the machine on and position the tool for setting it up The rest is controlled from the computer via the printer driver The control panel looks like this Figure 15 Control panel of MDX 40 The important controls are described below Power on off button When powered on the machine moves to a datum point and then parks the tool It is then ready for use Note that the machine needs to be powered on so that the computer can see it View Button When pressed this interrupts whatever is going on moves the tool clear of the work and moves the table to a forward position where it can easily be seen Once the table and tool have parked the guard can be opened and the part inspected Pressing the view button again resumes the machining where it left off The green LED lights up when a view is in progress It is not possible
8. interest here PCB Engrave Setup Engraving Cutting Tools Tool Park Tool Engraving Mas Depth Horiz Vert Spindle 0 0mm Diameter Depth per Pass Feed Feed Speed A W Engraver 030mm Y 305 00rmm amn 025mm o oos fos f Slot Drill 100mm 025mm 050mm 100mm 10 Ormns sooo Tool Change i Use engraver for tracks i 0 0mm ka Drills Details iT Tool Vert Spindle Board Thickness 160mm j 0 0mm Diameter Feed Speed spot Depth 0 50m M Dill no 1 0mm 5mm psom T Drill no 2 Pimm Emms poo Clearance 2 0mm Dril no 3 Set Default Load took nave tools t Imperial i Metric Drill no 4 B Cancel Help Notice that the engraving tool is already defined as are the board thickness and the clearance height for rapid moves The spot depth is the depth used by the vee engraving tool to spot drill the holes in the pads If the holes need to be drilled as would normally be the case then one or more drills need to be selected to match the diameter Assuming that the PCB contained pads with holes of 0 8mm diameter the following setting would be made All holes 0 8mm diameter will be recognised and drilled as a second operation If holes of other diameters exist they will be ignored Drills Tool Vert Spindle Diameter Feed Speed M Drillno t 0 80mm 15 0mm s fi5000 F Dilnoz fi00mm 50mm 15000 M Dailno3 f1 20mm 50mm fi5000 T Diino 150mm fi5 0mms fisoo0
9. is View Peni Window Help all lie Drawing Layout Customise Canvas Scale Prink Options Units CAL Devices CNC Output Offset gas ascii Grid Coordinates Load Setup Attach Save Setup Radial Lock Set 4s Default tf Galway Education Centre 49 CNC Routing Choose the Set for CNC device option and select the MDX 40 from the drop down list This will automatically resize the work area to the table size of the machine Select ok to close the window 0 Standard size i Set for CNC device RotoCAMM MOe 40 x ance C Match current printer yeuropaCanon iA5000 Help User defined t Imperial C Set for Font Design f Metric Material Size Orientation Device Device r 305 00 305 00mm Material offset On Oy 0 0mm 0 0mm Rotated The software is now set up and ready to use While this may appear long and complicated in practice setting up the tools and machine only takes a short time 50 Ot Galway Education Centre CNC Routing Appendix 2 Importing a CAD Drawing and Setting it up for Machining Drawings can be imported from a SolidWorks drawing sheet using DXF format See the section on file conversion elsewhere in this document In SolidWorks select File Save As and select DXF as the file type Make a note of the file name and location and quit SolidWorks Start 2D Design and cr
10. range of processes possible for it For many of the processes the starting point will be a CAD model or drawing The workings of CAD systems are not discussed here Types of CNC Machine There are three common types of CNC machines used in the classroom In each case they can greatly simplify the manufacture of an item or in many cases permit the manufacture of an item that would otherwise be impossible The applications of each are described below CNC Lathes These will be a familiar item to many people as they have been in Engineering rooms in schools for many years The most useful application is in the production of parts that have radiused corners tapers and threads that are difficult to produce otherwise Boxford and EMCO are the two most common manufacturers and are described in more detail in a later section Laser Technology Laser is a relatively new technology in the classroom and offers a very versatile and easy means of producing items from wood and plastic materials The machines are very easy to set up and use there is no need to clamp the workpiece and behave in much the same way as a printer or plotter The laser machine is driven directly from the CAD system or graphical package being used Figure 1 Laser cutting machine Ot Galway Education Centre l CNC Routing There are two main applications for laser machines 1 Laser Cutting Laser cutting is quick accurate and leaves a clean cut It is useful for p
11. software package such as TechSoft 2 D design This allows the profiles of the items to be imported from a CAD system and cut on the machine Features such as holes pockets and bosses can be produced as well The user interface of these packages is often basic and drawing and editing of complex shapes is best completed before exporting the data from the CAD system PCB Manufacture Manufacturing a PCB from copper clad board allows versatility in Technology projects where a pupil can design a circuit and then manufacture a PCB to fit a particular project or application Because there are no toxic chemicals involved as is the case with PCB etching it is a very suitable process for the classroom In order to manufacture the PCB a specialist PCB manufacturing software package is used One such package is TechSoft PCB design and make The PCB design is generated beforehand using software such as PCB Wizard or Circuit Wizard and then imported into PCB Design and Make From there it is a relatively simple matter to machine the tracks and holes as the software handles the details of tool offsets cut depths sequencing etc PCB Design PCB Artwork Machined PCB Figure 4 Stages in PCB manufacture tf Galway Education Centre 3 CNC Routing 3 D Machining Machining of complex parts such as forms for vacuum forming moulds and models requires a 3 D machining software package This differs from the 2 D software in that it can import a three dime
12. t Galway Education Centre 57 CNC Routing Appendix 5 File Transfer between Different Systems All CAD and CAD CAM systems differ in how they work and how they represent the drawing or part being modelled For example a 2 D CAD system will be concerned with lines arcs and their start and endpoints A solid modelling system will need to deal with features such as extrusions cuts and a design tree A PCB design package will have information on tracks pads and component values All of these systems need to save their work to disk for later use As these systems have developed over time each will have devised a file format that is most efficient for their particular needs The format used will be specific to the type of information being stored e g lines arcs and will typically use the least space on disk and load quickly when opened Native and Neutral File Formats It is not surprising therefore that a wide variety of file formats exist for saving CAD CAM data Neither is it surprising that each filetype can usually only be read by the application it was designed for there are a small number of exceptions A list of commonly used file types are shown below There are many more TechSoft 2 D Design Circuit Wizard TechSoft PCB design and make If a particular system was to be able to read in the files from another then it would need to incorporate a routine to read decode and convert the data stored within it To read data
13. to do anything else with the machine until the view is cancelled Z Axis Jog Button This is used to adjust the height of the spindle when setting up a tool The axis moves slowly at first and then more quickly as the button is held Emergency Stop This is self explanatory It is the simplest way to bail out of a program ina hurry The machine will need to be powered on again afterwards to reset it There are three main aspects to using the CNC routing machine These are Workholding and operation of the machine Toolsetting Programming Workholding and Toolsetting are common to all tasks so they are considered first 10 tf Galway Education Centre CNC Routing Workholding The method used to secure the workpiece to the machine table will vary depending on the type of material being cut and the shape of the job itself For all tasks it is useful to fit a 4mm thick sheet of acrylic or similar over the machine table and then machine it flat This has two advantages e t provides a true flat surface for mounting the workpiece e ltcan act as a sacrificial surface that can be machined into if needed without affecting the machine table TechSoft provide a sheet of material cut to the correct size and a program ready to machine it It is strongly recommended that this is done before anything else Once the table is set up workpieces that are not porous can be fixed to the machine table using double sided tape This is ideal for PCB ma
14. A TECHNOLOGY SUBJECTS SUPPORT SERVICE Leaving Certificate Technology CNC Routing amp Applications TechSoft RotoCAMM MDX 40 Contents Applications of CAD Cam in SCNOOIS cccceccseeceeeeeeseeeeeeeeeeeeeneeaeees 1 Types of CNC Machines ite2ceciiseccsarccacncsassecnsdstinacnstessinasietxiensiosseresseevevedess 1 CNG Routers MillS eo seracraceerstccsostaatesosearaaconicitianossieesiearerantonrteanesstutaneienensneeads 3 CNC ROUTING INMOOUCTION icccucnccsencdeecesesgdenoenetenseceasesceenegeseneaceesanocercceu 9 Characteristics of the MDX 40 ccceccsecceeeceeeceeeseeeeeeseeeseeeeeeseeesaeees 9 Operation of the M CHING ccccecceeeeeceeeeeeeeeteeeeeeeeeeeeeeeaeeeeeeeeenaes 10 ZD real lae ee ee A E 16 20 IWIACIIIOIIIG EXC OISE vceccrsticcrocenccranesenewaresaaecmesaccrancsnanawesasmaaaeeeanunenananare 19 POOO IE eee eee eee ee ee eee ee 31 GVA CUI cae snd cydenat anotonatanetueovecieonatcnatenaisestonstuesteaceeatioate aiT 32 Designing and Manufacturing a PCB cccceccceecceeeceeeseeeaeeeeeeeeeeaes 34 KacnnN Ne POB esera E E E 39 APPONOIX Tesiri e E E E 46 APPNO hore son E A 51 APPENODC e A A E A 54 APPENA A a EE E EE Of APOENA Go aetna nnn ne ee eee eee ee ee 58 Wn OT CAD CAM ee a E 65 CNC Routing Applications of CAD CAM in Schools This section will first look at the types of CNC machines commonly used in a school setting Then for each type of machine an overview is given of the
15. B manufacturing programs are able to read Gerber files directly so this provides an easy means of transferring data from one system to another PCE For project del Ea PCB For project gbo Ei PCE For project gb1 Ei PCB For project gb R PCB for project gb3 Uses Export PCB manufacturing data from CAD to CAM Advantages A well established and easy way to convert specialised data for PCB Allows filtering out of unwanted items by ignoring certain files e g component side Limitations Useful for PCB manufacture only With additional software board outline and component shapes can be exported to CAD but only as 2 D profiles so it is generally not worth the trouble 64 Ot Galway Education Centre CNC Routing Origins of CAD CAM Introduction The term CAD CAM stands for Computer Aided Design and Computer Aided Manufacture The two are often used together to describe a process where an artefact is designed electronically using a CAD system such as SolidWorks or AutoCAD with the information from the CAD drawing being used to manufacture the component directly using computer controlled equipment such as a milling machine or lathe Over time both CAD and CAM have evolved separately and the seamless combination of the two is a relatively recent development This module will assume a working knowledge of CAD and will concentrate on the manufacturing aspects of the process There is a variety of CNC machine confi
16. Rectangle Horizontal Path Segment Then select the correct layer using the menu at the top left of the screen r Click here to change layer File Edit Draw View Setup Layer Board Profile L Finally draw the rectangle where the edge of the board should be It may be helpful to draw the rectangle to a particular size e g 50x40mm using the snap and grid and then to move it to a suitable position around the tracks as shown below 38 tf Galway Education Centre CNC Routing Machining the PCB 1 Without Copper Removal The procedure for manufacturing the PCB is identical to that of machining a 2 D part The PCB should be fixed to the front left of the table using double sided tape Make sure that the board is flat and level on the machine table Select File Make PCB to start the process Wake the PCB using an engravermillerncutterplotte Edit Draw View Setup Window Help New Ctrl M Open Chrl 0 SE Add Close k Save Chrl 5 Save S c Load Component E Save 4s Component Import File Export File a8 WA Print Ctrl F AB Print Setup Print Offset Make PCE Ctrl M Flot Offset 1 pcb For torch dtb 2 CADESTOOLS PCETutor3 dtb 3 CADESTOOLS PCBTutor1 dtb 4 CADESTOOLSI PCETutorz dtb Exit The window that appears next looks like its counterpart in 2 D design except that it provides some options on how the PCB is to be made Sel
17. Routing Figure 21 Toolholding in the MDX 40 To set a tool first the spindle is positioned in a suitable position over the workpiece using the printer driver on the PC This position is then set as the Z axis zero using the interface of the print driver Then the tool is fitted to the spindle with the collets loose and allowed to drop until it touches the workpiece The top collet is then tightened to fix the height of the tool If more tools are required they are fitted in the same manner and their top collets used to retain the height setting This has the effect of making all of the tools exactly the same length so that they can all be used at the Z axis zero just set 14 tf Galway Education Centre CNC Routing For some applications such as 3 D machining the lengths are set before running a program using the printer driver Roland Mox 40 Shortcut Figure 22 Printer driver dialogue for tool setting However for other applications such as PCB manufacture it is done as part of the print dialogue when sending a program to the machine The process will be shown for each of the examples below Caution If the tool height is incorrectly set it is likely that it will crash into the workpiece causing damage If in doubt remove the tool from the spindle and dry run the program beforehand to make sure t Galway Education Centre 15 CNC Routing 2 D Machining General Issues relating to 2 D machining The following po
18. Routing The parameters governing the characteristics of the PCB are chosen as options within Circuit Wizard during the conversion from circuit diagram to PCB The soldering of the PCB can be further simplified by machining away all of the remaining copper from the board and leaving just the tracks However boards made this way take much longer to machine so there is a trade off involved Drilling holes on a PCB There are a number of options for drilling the holes on a PCB Holes are recognised automatically and can be either spotted using the vee tool for hand drilling later or else drilled on the router as a separate operation If this option is selected then a separate toolchange will occur for each diameter drill required Manufacturing a PCB using the TechSoft Router The package used on the Techsoft is called PCB design and make It looks and behaves very much like 2 D design with some specialised functions to cater for PCB manufacture It is possible to draw up a PCB from scratch but most people will want to use it to machine an existing design from PCB Wizard or Circuit Wizard If this method is chosen then there is little to be done apart from setting up the machining area and choosing the correct size tools When first run up PCB design and make looks like this TechSoft Design Tools PCB Design and Make Untitled1 File Edit Draw View Setup Window Help 0X avs J So SP wees a Shee SON GE AA oe RY SS t
19. S OE ee oe SS Gy ah die Ke Gi cau aba ah ste Ak ee cis Se ue Ge of 2b cee a sp ox Si gah ey lee Gk ey ae Saas ee cope ae ek ee ee ee Ge ga Sey cn Sues ga ae ii J gt Abs Rel Distance l Angle j The environment looks a lot like 2D Design although there are some important differences To set it up for use Select Setup Load Setup and load the T4 configuration file This will set the defaults for the following exercise A detailed explanation of how the drawing area and tools are set up is given in Appendix 4 t Galway Education Centre 33 CNC Routing Understanding Layers in PCB Design and Make PCB design and make has a number of predefined layers similar to those found in CAD systems They are designated to different parts of a PCB such as Silk screen schematic etc All of the tracks reside on the Solder layer Most of the other names are self explanatory Anything drawn on the Board Profile layer will be machined to the full depth of the board If a rectangle is drawn or other shape if needed then it will be machined as the final operation Layers can be switched off or on to aid clarity in the same manner as a CAD system The correct layers are assigned to the different parts of the PCB automatically when a file is imported to the system Designing and Manufacturing a PCB The Circuit shown below is for speed control of a motor This exercise will involve creating a PCB for it and then exporting and manufa
20. Toolpath is only interested in the physical shape of the solid A few different neutral file formats have evolved over time each with its particular strengths and applications These are explained briefly below 60 Ot Galway Education Centre CNC Routing Drawing eXchange Format DXF DXF was originally developed by Autodesk the writers of AutoCAD as a neutral format for exporting and importing 2 D AutoCAD drawings Although it supports 3 D it is normally used for the transfer of 2 D graphical files between systems It represents the items as lines arcs points etc along with their coordinate data ENTITIES 0 LINE 5 27 100 AcDbEntity 8 0 6 CONTINUOUS 62 1 100 AcDbLine 128 6588971478 20 123 3424833098 30 0 0 11 Advantages It is supported by most 2 D graphical programs as well as the drawing editor in SolidWorks DXF files are accurate to six decimal places and so are suitable where accurately produced parts are required Uses DXF is best used in the following situations e Exporting a SolidWorks drawing for 2 D machining e Exporting a SolidWorks drawing for laser cutting Limitations e The way DXF files represent text means that it will usually not be read by the system importing the file and text will often disappear altogether e DXF files are not suited for transferring drawings containing bitmaps or similar raster images In most software DXF file creation is available as an option und
21. are made from a material known as copper clad board that consists of a paper based laminate material covered on one side with a thin film of copper The technical name for this material is FR2 The copper can be engraved away to form tracks that make up the circuit on PCB The production of a PCB involves up to three operations e The first is to engrave the tracks and pads using a vee engraving tool e Once the tracks are complete holes can be drilled in the pads to allow the wires from the components to pass through e The third optional operation is to cut the outline of the PCB to size A vee engraving tool typically makes a cut of about 0 3mm wide when cutting at 0 25mm deep This needs to be taken into account when designing a PCB and enough space needs to be left between adjacent tracks to allow the tool to pass between them If the tracks or pads are made too close together then all of the surrounding copper may not be removed Adjustments to the PCB are best made using the PCB design software PCB Wizard Circuit Wizard or similar beforehand When designing a PCB it is a good idea to make the tracks and pads and isolation gaps as large as the size of the PCB will allow This makes soldering easier and reduces the chance of over soldering and short circuits The diagrams below show the same circuit The PCB on the left has increased track and isolation gap widths ej TETZA 32 t Galway Education Centre CNC
22. boxes Enter a value of about 90mm in the Z box before pressing the button This will move the Z Axis to a closer position to the table Now fit the cutting tool loosely and let it drop down to touch the top of the workpiece Tighten the upper and lower collets Leave the tool in place and press the Output button The following window will appear Tool Change Instructions PUWPORTANT Y FIRST WAIT until machine has mowed to the tool change position and the spindle motor has fully stopped THEN FIT tool 7 for colour i THEN CLICK Continue or Skip or Abort in so Press continue This will start the machining of the recess around the window opening At the same as this is being machined time the following window will appear prompting you to wait until the present machining has stopped before fitting Tool 2 Tool change instructions P PORTAT g FIRST WAIT until machine has mowed to the tool change position and the spindle motor has fully stopped THEN FIT tool 1 for colour THEN CLICK Continue or Abort sot _ The machine will switch off when machining is complete 30 t Galway Education Centre CNC Routing Projects 1 Design and make a noughts and crosses game 2 Design and make the square triangle circle game tf Galway Education Centre 31 CNC Routing PCB Manufacture PCB manufacture is quick and easy using the Techsoft Router and PCB Design and Make software PCBs
23. ctions PUMPORIANT Y FIRST THEW THEN WAIT until machine has moved to the tool change position and the spindle motor has fully stopped FIT engraving tool CLICK Continue or Skip or Abort sin _ son When the operation has finished fit the 0 8mm PCB drill and then continue to start the drilling operation Tool Change Instructions y FIRST THEW THEN UPORU Y WAIT until machine has moved to the tool change position and the spindle motor has fully stopped Fit PCB drill 0 80mm CLICK Continue or Skip or Abort Skip Abort When this is finished a prompt appears for the 1 2mm drill Fit the drill and press continue Tool Change Instructions J FIRST THEN THEN NPORT F WAIT until machine has moved to the tool change position and the spindle motor has fully stopped Fit PCE drill 1 20mm CLICK Continue or Skip or Abort so _ son Finally a prompt appears to fit the engraving tool once again to cut the outer profile The PCB is now complete Tool Change Instructions j FIRST THEN THEN t Galway Education Centre CUN PORTANT Y WAIT until machine has moved to the tool change position and the spindle motor has fully stopped FIT engraving tool CLICK Continue for Skip or Abort so ao 4 CNC Routing 2 With Full Copper Removal With full copper removal all of the copper surroundi
24. cturing it First Start Circuit Wizard and load the file Motor Speed Control cwz Creating a PCB Start the process of converting the circuit by clicking on the icon at the top right of the toolbar a Convert to PLB Layout Convert a circuit diagram into a printed circuit board PCB layout 34 t Galway Education Centre CNC Routing Click Next and select the Single Sided Thick Tracks option as shown below Convert to Printed Circuit Board Choose how you wish to convert your design into a PCB layout and then click Next to continue ae Single Sided Thick Tracks ee Single Sided Normal Tracks oe Single Sided Thin Tracks e Double Sided Thin Tracks a Placement Only Mo Routing EM Rats Nest No Placement or Routing omments Creates and routes simple single sided boards with large pads and thick tracks allow me to customize the PCB layout conversion lt Back Cancel Help Accept the defaults for all the following dialogues until the conversion is complete The PCB should now look like that shown below lt o 11P 121 R1 1N4001 gt The PCB is now ready for manufacture However if desired the placement of the components and track widths etc can still be changed if desired First make sure that Interactive Routing is enabled ae Check Integrity Insert Met f Optimize Mets e Suto Optimize i a aa es a t Galway Education Centre 35 CNC Rou
25. d to be rotation about either the X Y or Z axis These rotary axes are usually labelled A B and C respectively Therefore it is possible for a machine to have four five and even six axis control In practice more than four is rarely needed At least one desktop router manufacturer offers a fourth Axis dividing head This type of configuration allows the machining the top sides and underside surfaces of a component without the need to turn it over Figure 35 Router with a fourth rotary axis 70 t Galway Education Centre CNC Routing Principles of a Practical CNC Control All practical CNC systems contain three elements e The control e Current Amplifiers e Servo Motors Current Amplifier Servo Motor Figure 36 Block diagram of a CNC system The control is the brain of the system The control reads the instructions from the program and performs all of the calculations and measurements that determine where the cutting tool should be for any given instant in time during the run of the program This can be a complex process using advanced mathematical principles The result is that the control can send signals to the servo motors to control the axis positions up to several hundred times per second The type of signal sent depends on whether Open loop or Closed loop control is used see below The output from the control is usually a small voltage typically plus or minus five volts In order to drive t
26. d both to mass produce simple components and to manufacture difficult items such as cavities for injection moulds The machines were programmed by a text based programming system called Word Address more commonly known G Codes because of the appearance of the program The programs are commonly called part programs The programs are keyed directly into the machine control or else generated elsewhere and then downloaded to the machine There is some variation in the format and syntax of word address programs due to different adaptations of it by a range of CNC control manufacturers A fragment of a typical part program for a milling machine is shown in Figure 30 below N5 GOO G90 X100 0 YO 0 T1 MOG Rapid to tool change position Load Tool 1 N10 G43 X5 0 Y 5 0 21 0 851200 M03 M08 Move to start of profile Start spindle N15 G01 G41 Z 5 0 F100 Feed to depth N20 X90 0 Linear cut along profile N25 G03 K100 0 Y10 0 10 0 210 0 Circular arc move Figure 30 Sample of a G Code part program Using this system the programming of simple parts is relatively straightforward and making changes to a program is easy However manual programming by its nature is prone to error and for more complex shapes such as curved or sculpted surfaces the program needs to be generated from a CAD system CAD systems themselves originated around the same time as the early NC machines but remained expensive and therefore rare until the advent of cheap computing in t
27. dWorks and then import the drawing into 2D Design for machining The issue of file transfer between different software systems has been discussed earlier The issues relating to setting up cutting tools and cut depths are dealt with in Appendix 1 18 Ot Galway Education Centre CNC Routing The detail of creating toolpaths to machine the part is explained in Appendix 2 The detail of setting the tool datums and machining the part are explained in Appendix 3 2 D Machining Exercise The aim of the exercise is to produce the picture holder shown below First a partly complete drawing will be imported into 2D Design Then further geometry will be added to it before creating a toolpath and machining it Figure 27 Picture Holder To save time a predefined tool setup will be used as follows Colour Tool Diameter Depth Depth pass Feed Speed _ 1 2 0 3 1mm 1mm 40mm s 12 000 rev min 1 2 0 0 5mm 1mm 40mm s 12000 rev min Start Techsoft 2D Design and do the following before starting the exercise 1 Load the setup file Frame Template Setup CFG that is supplied This will set up the tools and depths of cut as well as the work area size and the material blank 2 Select Setup CNC Devices and make sure the plot device and print driver are set to the Roland MDX 40 print driver as shown in the window below This step can be ignored if the MDX 40 is already set as the default windows printer Otherwise it will
28. e tool Fit the 0 8mm PCB drill tighten the top collet and remove it as well Repeat the same procedure for the 1 2mm drill This has the effect of making all of the tools the same length see the section on tool setting for 2 D Design above for more detail Now select Make PCB to begin the machining process Fit the engraving tool and press continue to engrave the tracks Tool Change Instructions PUMP ORTANT F FIRST WAIT until machine has mowed to the tool change position and the spindle motor haz fully stopped THEN FIT engraving tool THEN CLICK Continue or Skip or Abort tin _ tor When the operation has finished fit the 0 8mm PCB drill and then continue to start the drilling operation Tool Change Instructions FWP OROANT Y FIRST AIT until machine has moved to the tool change position and the spindle motor has fully stopped THEM Fit PCE drill 0 50rnrn THEN CLICK Continue or Skip or Abort sin _ tot 44 t Galway Education Centre CNC Routing When this is finished a prompt appears for the 1 2mm drill Fit the drill and press continue Tool Change Instructions PNP ORTANT amp FIRST THER THER WAIT until machine has moved to the tool change position and the spindle motor has Fully stopped Fit PCB drill 1 20mm CLICK Continue or Skip or Abort Skip Abort Finally a prompt appears to fit the engraving tool once again to cut the
29. e trimmed back later UNDO s EL Last Right Click on the Attach button and make sure the settings are set to those shown on the next page 24 Ot Galway Education Centre CNC Routing Attach Settings Attach entiti ach entities W Atach Or x End point or node Mid point of lineare Centre of arc circle Nearest point Perpendicular OF Tangent Intersection Cancel z a 2 z z z Construction point Help Ii Include text Attach target 2 Z of screen height Now start to edit the geometry With Attach and Radial Lock on create two horizontal lines from the base of the letter as shown below Now use the Delete between intersections command to remove the unwanted lines from the outer profile It should now look like this B t Galway Education Centre 25 CNC Routing Next edit the detail at the base of the letter to form a profile that can be machined through Delete the two lines at the base of the legs of the letter and create a new line to form a rectangular profile between them Finally add a fillet of radius of 3mm on the outside shoulders of the part 26 Ot Galway Education Centre CNC Routing The part is now ready for assigning toolpaths Remember the tool settings made earlier Colour Tool Diameter Depth Depth pass Feed Speed _ 1 2 0 3 1mm 1mm 40mm s 12 000 rev min 1 2 0 0 5mm 1mm 40mm s 12000 rev min Therefore the colour red must be
30. eate a new document so that the work area is blank Now select File Import File and choose DXF as the file type Locate and select the file you created earlier Choose the following options in the window that appears DXF Import Setup i Interpret units and Position i Fitto media Units Interpretation and Position Cinch ke Centre in window mm Scale on Z W Load as a Group Dimensioning Preference f Exact match always exploded C Nearest match retain dimension properties if possible OF Cancel Help Once the profile is imported select and drag it to a suitable position near the bottom left of the machine table t Galway Education Centre 51 CNC Routing The next step is to assign cutting tools offsets and depths to the profiles Remember that the three depth tool combinations have already defined in Appendix 1 and are assigned to line colours Therefore the toolpaths need to be created using these colours First we will look at the outside profile and the two holes These are to be cut through and so will use the colour RED Select the drawing colour RED from the toolbar at the top of the screen i 2s Cole EGRE C Se The tool will need to cut outside of the outer profile and inside the holes so allowance will need to be made for the diameter of the tool This is done using the contour tool on the left hand toolbar This creates a profile offset by a given amount from an exi
31. ect Solder Side only and make sure that Full Copper Removal is off Make PCB fx Plotting device P oland MDY 40 Serre Connection tion Through printer driver Roland MO 40 Connection Production Method Rotated f Solder side only f Component side only x C Double sided board C Laminated board Cancel Full Copper Removal Bi ekticts Help r t Galway Education Centre 39 CNC Routing Select Ok and a preview of the cutter path will appear eee TechSoft Design Tools PCB Design and Make F Select Yes and the tool setting window will appear in the same manner as for 2 D Design Tool Set Point Check Change the Tool Set Point a 5 0mm Y 5 0mm Z gg a Move to Tool Set Paint C Imperial w Keri Make PCB Cancel Help To set the tools choose a value of 90mm for the z tool set point and move the tool to there using the button Fit the engraving tool so that it touches the top surface of the PCB tighten the top collet and remove the tool Fit the 0 8mm PCB drill tighten the top collet and remove it as well Repeat the same procedure for the 1 2mm drill This has the effect of making all of the tools the same length see the section on tool setting for 2 D Design above for more detail 40 Ot Galway Education Centre CNC Routing Now select Make PCB to begin the machining process Fit the engraving tool and press continue to engrave the tracks Tool C hange Instru
32. er either File Export or File Save As and selecting the correct file type t Galway Education Centre 61 CNC Routing Save As Save in O CAD CAM resources i G F gt fae photos iE game 2d Exercise DXF 0 2 D profile in bw DXF 8 objects only dxf L My Recent Documents 8 2dpart For mill with colours dxf 8 PCB for project dxf WE 2Dpart For mill with different options DXF Hr12dxf dxf 0 2Dpart For mill DXF H Sample 2 D part For tutorial DXF Nf 2000dxf dxf istandard dxf dxf H calculator exercise DXF H test For 2 D dxf lt ei Filename 2Dpart for mill DXF sae J Save as type Def def v Drawing drw slddrw Description My Network Places DXF files are imported similarly by using File Open or File Import Sterolithography Files STL files This file format was originally developed for transferring data between CAD systems and rapid prototyping Stereolithography systems It is commonly used to transfer the physical shape of a solid modelled component from one system to another e g from SolidWorks to a 3 D Machining program for generating toolpath 60 NNN PSP i Mest REN oie ie iw en Y SS aS SSNS Figure 29 SolidWorks model of a part and its STL representation In STL the shape of the item is represented by a series of triangles that approximate its outer sur
33. essary to define a box around the volume to be scanned in the X Y and Z directions This is easily done once the size and position of the item on the machine table is Known One important issue with 3 D scanning is the usability of the file once it is imported into the CAD system Often the amount of editing that can be done to the CAD model is limited particularly in systems such as SolidWorks that are based on parametric design However for simple applications such as with engraving packages the scanned file is perfectly acceptable Figure 8 Touch probe and part to be scanned t Galway Education Centre 5 CNC Routing Figure 9 The default scanning volume is the entire motion envelope of the machine Figure 10 Small envelope confining scanning to the volume of the component 6 tf Galway Education Centre CNC Routing Engraving Carving Lithopane Machining These processes may be less familiar than the more common applications for routers but offer a wide range of opportunities in the classroom They all share one thing in common They involve taking a 2 D object such as a photograph or profile and giving it a third dimension This 3 D object is then projected onto a surface or a plane depending on the application and then machined into it In each case a specialist software application is needed These engraving software systems are usually limited in what they do e g engraving only due to the degree of
34. exactly the same manner Uses e When exporting CAD files containing text for laser cutting e When exporting CAD files containing 2 D profiles for laser cutting DXF preferred e When exporting raster images for laser engraving Limitations e All the items are transferred using integer arithmetic and will appear as a picture object when they have been pasted This means that there is likely to be some loss of accuracy It is usual to have to resize the pasted item back to its original size before processing e Effectively limited to any item that can be represented as a picture i e 2 D profiles PCB layouts raster images etc not 3 D entities such as CAD models Gerber Files Gerber Files resemble CNC programs in appearance and this gives some clue to their origin They were originally developed to drive the Gerber Photoplotting machines that were used in producing masks for PCB manufacture Gerber files can contain all of the manufacturing information relating to a PCB Gerber files are usually generated in a set from a PCB design package each file defining one aspect of the PCB For example one file will contain the details of the tracks solder side and another the sizes and layout of the components component side yet another the drill holes Ot Galway Education Centre 63 CNC Routing and so on The files are generated automatically using File Save As or File Export option from the PCB design package PC
35. eyscale projecting it onto a plane and letting the software generate the cut depths and toolpath Bitmap image Converted to 3 D surface Machined Lithopane Figure 13 Stages in the production of a lithopane image Production of a lithopane is very easy and quick and is expedited by a Wizard that moves through the process step by step 8 tf Galway Education Centre CNC Routing CNC Routing Introduction This section deals with using the TechSoft MDX 40 routing machine and the material contained here is specific to it In order to set the MDX 40 up for use it is necessary to carefully follow the steps given in the machine setup guide In particular the Roland printer driver must be installed and a shortcut created to it It should appear on the desktop like this ae al Roland MO 40 P Shortcut TechSoft provide a comprehensive set of tutorials for using the various options and it is recommended that these are worked through thoroughly Characteristics of the MDX 40 The TechSoft MDX 40 is a three axis routing machine The table area is 305mm x 305mm with a working height of 100mm approximately The machine head is mounted on a gantry which provides movement along the X axis The machine table moves to provide a Y axis The head can travel upwards and downwards to provide the Z axis The machine spindle can hold tools up to 4 5mm diameter and rotates at 15 000 rev min The tool can travel at up to 50mm s in the X and
36. face The format can also show which side is the inside and the outside of the part The accuracy of the shape can be controlled by increasing or decreasing the number of triangles but in general this is not necessary Advantages This is a quick and simple way of exporting a complex 3 D solid modelled shape to another system 62 Ot Galway Education Centre CNC Routing Uses Export of a 3 D solid modelled part to another system for machining or rapid prototyping Limitations e All of the design and other information colour texture etc are lost so this is not suitable for export to another CAD system for example that may want to use this data e tis not suitable for exporting importing anything other than solid models Windows Metafiles These are the files that are created when items are cut and pasted using normal windows commands Edit Cut Copy and Edit Paste Entities can be copied from one program and pasted into another In some cases this is the only possible way to export import between different software and in many cases it greatly simplifies the process There are some limitations however Advantages Allows the cutting and pasting of a wide variety of data such as text pictures of all types CAD drawings across widely different software For example a 2 D CAD drawing can be pasted directly into a word document or into another CAD program or into an image editing program such as Paint in
37. from a variety of systems then a similar routine would be needed for each It is easy to see that this would quickly become impractical if many file formats were to be supported 58 Ot Galway Education Centre CNC Routing The partially complete diagram above gives an idea of this Each of the arrows represents a conversion routine to another file format To further complicate matters software manufacturers rarely publish the format of their native file formats and in any case they are prone to revision without notice as the software is updated and developed In practice a neutral file format is usually used to transfer data from one system to another The file format is published and understood by all t Galway Education Centre 59 CNC Routing System A Neutral file format It can be seen that this arrangement is much simpler Each software package needs only one translation routine to import from and to export to the neutral file format To convert data from any system to any of the others a file is exported in the neutral format and imported by the receiving system The neutral file format itself will by its nature be a compromise and there will often be some loss of system specific information e g the design tree in SolidWorks in the translation However this does not pose a problem as these features are often not needed by the system subsequently reading the file for example a machining program such as Visual
38. gurations manufacturers and an even greater variety of processes available to the Technology teacher It would be beyond the scope of this document to give a comprehensive treatment of each machine each process and its associated software application Instead a general overview is given of what is possible and how this may be achieved Then a machine specific example of each is presented with enough detail for it to be replicated in the classroom In addition to this a brief summary of the development of CAD CAM is given as well as a section on the principles behind CNC History Computer Numerical Control All of the manufacturing equipment used involves controlling the movement of a cutting tool of some sort in a precise manner Both the positional accuracy and speed of travel are important and these need to be controlled precisely in order to achieve the desired outcome This control of the tool path is achieved by Computer Numerical Control CNC systems built into the machine tool The systems have two aspects e How they control the motion of the cutting tool e How they are programmed In order to better understand how present day systems have come about it is useful to look at the development of CNC over time Early Numerical Control As early as the late 1940s as the cold war between the US and Russia escalated the American aerospace industry began to need complex aerofoil shapes to cater for aircraft and missile manufacture These
39. he amount of error This voltage controls the direction of the servo and has the effect of trying to pull it towards its correct position The greater the error the stronger the pull If a particular axis is programmed to move say 10mm at a speed of 1mm s then it will calculate each intermediate position for the axis in 1 500 second intervals and then vary the demand voltage to pull the servo towards each of them over the course of the ten seconds taken to complete the move Once the move is complete if a force tries to move the axis out of position say a collision with the cutting tool the control will detect an error between the ideal and measured positions and will try to move the axis back into position It can be seen that this type of control is more reliable and offers greater accuracy than the open loop system described earlier Closed loop systems are used widely in CNC equipment and robotics and they are the norm in all but the simplest systems t Galway Education Centre 73 CNC Routing Actual position from encoder Compare to actual position Calculate Generate Converts desired Voltage voltage to axis based on current to position difference drive servo Interpret program Figure 40 A Closed loop control system 74 tf Galway Education Centre
40. he early 1980s when they started to become commonplace Having defined the shape of a part to be manufactured using CAD the next logical step was to use the CAD geometry to generate a program for the CNC tool directly thus eliminating the need to write programs like that shown in Figure 30 above This approach is still common Denford routers for example use a version of the language known as Fanuc OM So called because it is used by the GE Fanuc CNC control which is fitted to many machines There is a variety of software packages available to generate programs These take the CAD data and post process it to produce a CNC program that is then loaded into the machine control from the CAD computer using a cable 66 Ot Galway Education Centre CNC Routing This type of software combined with the CNC is commonly referred to a CAM system Computer Aided Manufacture The entire process is usually referred to as CAD CAM The two most important functions a CAM program performs is to first add in extra information that the CAD drawing would not have such as cutting speeds feeds clearance moves tool offsets etc It then generates a G Code program in the correct format for the machine it is being sent to These programs are often very long several thousand lines as they are commonly used to machine items such as mould cavities where many short moves are required The process is shown in Figure 31 Figure 31 Schematic of the CAD CAM pr
41. he servo motors a current amplifier is needed This uses the voltage signal from the control called the demand voltage to control the current that powers the servo motors The servo motors are the final part of the system There are two types commonly used Stepping motors are a specialised type of motor that moves in very small increments steps controlled by voltage pulses A stepping motor typically rotates 1 8 degrees per pulse If 200 pulses are sent to the motor it will turn through one complete revolution The speed of the pulse train will control the speed of the motor They are usually used with Open Loop control The second types of motors are AC or DC servo motors These behave in a similar manner to a conventional AC or DC motor but are designed to provide more constant running characteristics These motors will exert a torque in proportion to the current running through them They are used with Closed Loop control only t Galway Education Centre 71 CNC Routing Open and Closed Loop Control Open Loop This is the simplest type of control and contains the three basic elements described in Figure 36 above stepping Control Motor Unit Figure 37 Elements of an open loop control This is shown in more detail below The open loop system works as follows Say that the control has calculated that a particular axis needs to move a distance corresponding to 80 pulses at a constant speed equivalent to 10 pulses pe
42. ints apply to 2 D machining across all applications This type of part consists of one or more profiles each machined at a constant depth Clearly a two dimensional drawing of a single profile cannot represent the part completely and information regarding where to cut and how deep needs to be added As well as this heights for clearance moves between profiles soeeds and feeds need to be entered also Taking this into account a simple 2 D part will often be more complex to set up than a 3 D one Machine manufacturers tend to each take their own approach to addressing these issues The following section deals with the Techsoft system only Main Considerations in Setting up a 2 D Part Consider the desk tidy project shown below Figure 23 Desk Tidy project 16 Ot Galway Education Centre CNC Routing ail at Figure 24 Desk Tidy before bending Note that the roughing toolpath has been omitted for clarity in this example In order to produce the part accurately the tool must cut to the correct side of the profile as shown below To do this the diameter of the tool must be known beforehand It must also move clear of the workpiece when moving from one profile to another and move to the correct depth of cut afterwards Figure 25 2 D profile showing tools and offsets As each profile is cut to a different depth these need to be set up This is achieved on the Techsoft machine by assigning a particular line colour to a too
43. l depth combination when drawing the profiles Say for the above part the Thickness of the material is 5mm the pocket is 3mm deep and the text is engraved 0 5mm deep et t Galway Education Centre 17 CNC Routing BE 4 2008 Figure 26 Profile showing colours assigned to different depths of cut In this example the profiles drawn in red are cut to the full depth of the material thickness the blue and green would be the depth of the pocket and the engraved text respectively It is usual to be able to assign different cutting tools soeeds and feeds for a particular colour so the setup for the part above might look something like the following Colour Tool Diameter Depth Feed Speed 2 3 5mm 20mm s 12 000 rev min rev min rev min In the above example all profiles drawn in red are machined to a depth of 4mm using Tool No 1 at the speeds and feeds specified This principle will be put into practice in the next section 2 D Machining on the TechSoft MDX 40 TechSoft provide a software package called Design Tools 2D Design for this purpose It offers a CAD like drawing environment that allows items to be drawn up from scratch It also allows the setting up of tools and toolpaths as described above There is a comprehensive user manual outlining the functions of all the drawing and editing tools 2D Design is adequate for simple shapes For more complex designs it may be easier to use a CAD system such as Soli
44. n it will be able to resume work on a partly machined item The machine Zero point is located near the bottom left of the table for the X and Y axes and near the highest point of its travel for the Z kn Figure 17 Machine Zero point Tool Length Offsets It is common to use the top of the workpiece as the datum for the Z axis i e Z 0 for the top surface of the billet Figure 18 Location of the Z axis datum 12 t Galway Education Centre CNC Routing This is obviously not the same as the machine zero Furthermore when a cutting tool is fitted it will project down below the machine zero The machine will have to compensate for the gap between the tool and workpiece when calculating where to move es r y E i Figure 19 Gap between tool and workpiece This is further complicated when several tools e g a roughing and a finishing tool are used as they may have different lengths Figure 20 Tools of different lengths Fortunately there is a simple way to solve this problem With the MDX 40 all the cutting tools feature a long shank 4 5mm in diameter that is held top and bottom by brass collets and grubscrews The bottom collet secures the tool in the machine spindle and the top collet provides a means of controlling the height of the tool Once the top collet is set the tool can be removed and replaced later without losing its height setting Ot Galway Education Centre 13 CNC
45. need to be selected each time 2D design is run tf Galway Education Centre 19 CNC Routing CNC Devices Setup Current list of CNC devices Roland MOex 40 Roland Modela MDX 15 Roland Modela MD 20 Roland Modela MD 3 Roland Stika SCF 85W75 Roland Stika ST8 7 Roland Stika 5 T 8 Roland Stika 5 12 Roland Stika 5W 15 narrow Roland Stika SY 15 wide Roland Stika 5 8 Roland Stika 5 12 Roland Stika 51 15 narrow Roland Stika 5 15 wide Roland Stika 5 8 RotoC MM MO 40 Output Route Through printer driver Foland MDe 40 Use Operation Panel by default Cancel Help Now open the file Frame TEMPLATE dtd that has been supplied to you It should appear like that below The size of the material blank is represented by the dotted rectangle drawn outside the part profile The first task will be to add a customised shape in the space provided at the top of the drawing The text command will be used to create the shape of a letter that will then be edited to become part of the outside profile 20 Ot Galway Education Centre CNC Routing Zoom in close to the top of the shape allowing some space to the right to create the letter Select the Text command on the left toolbar to produce the following dialogue box Text Entry i Settings l i l l i Cancel Help Click on the Settings button to show the following window Text Settings f Qutline Fort f TechSolt Font
46. ng the tracks is machined away as well The cutting tool traverses back and forth across the workpiece making cuts at close intervals As the effective diameter of the tool is just 0 3mm this process can add several minutes on to the machining time for a PCB The procedure for making a board with full copper removal is very similar to that just explained above except that the drawing layout needs to be edited so that the drawing area matches the size of the PCB This puts a limit on the area for copper removal Select Setup Drawing Layout and set the board area to slightly larger than the board size as shown below Moving the PCB to a position near the bottom left of the machine table will reduce the amount of material to be machined Board Layout x Board Area 51 D mm si O mm C Match print area of Roland MDX 40 Match plot area of plotting device Plotting device Set plotting device Roland MDX 40 X Orientation Rotated Imperial e etic Cancel Help The board area is now resized to the same size as the PCB st abject s Abs E 42 t Galway Education Centre CNC Routing Select File Make PCB to start the process Wake the PCB using an engravermillerncutterplotte Edit Draw View Setup Window Help New Ctrl M Open Chrl 0 SE Ada Close k Save Chrl 5 Save 4s c Load Component E Save 4s Component Import File i Export File a8 WA Print Ctrl F
47. nsional representation of the part to be made rather than just a two dimensional profile as previously The starting point is to generate a solid model of the item to be made using CAD software such as SolidWorks This is then exported into the 3 D software where toolpaths are generated for both the roughing and finishing of the item The software is often wizard based and leads the user through a series of logical steps through the process of preparing the machining sequence Graphical simulation of the toolpath allows a realistic preview of the part to be generated 3 D machining is one of the most powerful features of the desktop router and should contribute significantly to the development of Technology projects Figure 5 CAD model of part Figure 6 Model of part showing toolpath 4 t Galway Education Centre CNC Routing Figure 7 Machined part 3 D Scanning In 3 D scanning an existing component can be reverse engineered by using a touch probe to capture a grid of points on its surface and store them as a CAD model This is particularly useful where an existing complex part exists that needs to be copied or have something machined or engraved onto its surface The way of making a 3 D scan is not very different from using a 2 D scanner to scan a document The main difference is the third dimension In a conventional scan the area of the page to be scanned is defined before performing the scan With 3 D scanning it is nec
48. nufacture and for the machining of acrylic It also has the advantage of offering no obstacles for the tool to collide with during machining The tape used is a special grade that peels cleanly from the workpiece afterward and is supplied by TechSoft The double sided tape available in stationery shops leaves a residue that can be cleaned using a solvent such as paint thinners For workpieces that are not suitable for tape a vice can be taped to the machine table and used as normal However more care must be taken to ensure that the tool does not interfere with the vice A third option available on TechSoft machines is the self centering vice This is described in more detail in the section on 3D machining The datum for most operations will be the bottom left of the machine table as one looks in from the front of the machine so most workpieces are mounted accordingly However it is a simple matter to set the datum point to anywhere else if needed Figure 16 View of the machine table tf Galway Education Centre 11 CNC Routing Toolsetting on the MDX 40 The machine offers a simple and user friendly means of setting up cutting tools Before looking at this it is necessary to understand the issues involved Machine Datum Points When first powered up the machine seeks a homing point on the X Y and Z axes This provides an accurate and repeatable means of zeroing each of the axes and means that even if the machine is powered dow
49. ocess CAM systems usually offer some means to preview the toolpath or simulate the cutting process before generating the program They often offer a CAD like drawing functionality that eliminates or reduces the need for a CAD system There are a variety of CAM systems commercially available AlphaCAM is one system that is popular with the manufacturing industry in lreland at present Present Day With the reduction of the cost of CNC systems and computing a variety of light desktop machines have emerged in recent years These were originally aimed at the modelmaking industry and offered a low cost alternative for the cutting of soft materials such as wood and plastic These machines often share many of the characteristics of a printer and offer a graphical programming system where the user has little or no need to interact with the programming language used by the machine Unlike the complex user interfaces seen on full size CNC machine tools these machines usually offer two or three buttons to perform the essential tasks such as setting up a cutting tool The machines can be controlled using a printer driver or from other software on the computer This effectively replaces the machine interface This method is very simple to use and has been adopted widely in schools for routing machines vinyl cutters laser cutting etc t Galway Education Centre 67 CNC Routing Types of Machine In CNC the location of the cutting tool is specified b
50. ol change position and the spindle motor has fully stopped THEN FIT tool 7 for colour po THEN CLICK Continue or Skip or Abort i aon As the tool is already fitted press Continue to start the machining of the pocket t Galway Education Centre 55 CNC Routing At the same time the following window will appear prompting you to wait until the present machining has stopped before fitting Tool 1 Tool change instructions FUWPORUAKT Y FIRST WAIT until machine has moved to the tool change position and the spindle motor has Fully stopped THEN FIT tool 1 for colour rm THEN CLICK Continue or Abort Continue Abort When the pocket is complete press Continue again tool 1 is already fitted from the last operation to start the machining of the outer profile And so on until the machining is complete 56 et t Galway Education Centre CNC Routing Appendix 4 Setting up the PCB Design and Make for use The procedure for setting up the plot area and cutting tools is very similar to that described in detail earlier for the 2 D design system e Choose Setup Drawing Layout to set the plot area to match that of the MDX 40 305mm x 305mm e Choose Setup Plotting devices to choose the MDX 40 as the plotting device and set the Connection to the correct print driver as before Click on the pens tools button to show the following window There are a number of items of
51. outer profile Tool Change Instructions PUMP ORTANT F FIRST THEN THEN The PCB is now complete WALT until machine has mowed to the tool change position and the spindle motor haz fully stopped FIT engraving tool CLICK Continue or Skip or Abort in _ tot sr t Galway Education Centre 45 CNC Routing Appendix 1 Using 2 D Design Setting up the Machine and Tools The setup described in the next section applies in more or less the same format to all the 2 D software applications for the machine including PCB manufacture There are three main tasks 1 Select the machine i e the printer driver 2 Set up the plot area to match the machine table 3 Define and assign the cutting tools to be used When 2 D design is first run up the window looks like the following The white area in the centre corresponds to the machine table EJ TechSoft Design Tools 2D Design V2 Untitled2 2 Olsa ela IEA 4 s oala 2 w ooo Layer layert x Line Col F Fu co ff Non 2L j2 SELECT A TOOL DESIGN x lt il gt Abs Rel Distance Angle Title of the program Figure 28 TechSoft 2 D Design Before starting work it is best to set up the machine and tool parameters as they will affect how the software behaves The first task is to set the MDX 40 as the plot device Select Setup CNC Devices Desion V2 Untitled ae Window Help
52. p Ee a Pi n a s aq x ar Open CEOE tan ease a wae Re o Close iie a eal Save Chrl 5 ave 45 Page Setup EB Print a CaARICAM Export DAF Export MC Drill Send Export Gerber Properties 1E PEB For project cwe 2 Cih Buzzer incorporated cwe 3 Cih personal alarm cwz 4 Eia PCB For project cwz Exit Select File CAD CAM Copy CAM Data This copies the PCB design to the clipboard Then switch to PCB design and make and select Edit Paste or Ctrl V This will paste the design on the centre of the work area The design can then be dragged to the bottom left of the machine table as shown Indodup HOw S248700 Moj Juan Pho PSH pewon t t Galway Education Centre 37 CNC Routing Create a rectangle around the board profile as follows Draw a horizontal rectangle File Edit Tm Track Layer Bl ol Fil Col cakes B Round Pad f g Locate one Square Pad Abs L Elongated Pads Horizontal Elongated Pads Vertical Edge Connectors View Setup Window Help F Track Area rr F F Drawing Tools Single Line Text Connected Lines Chamber Transform Circle Centre Point Circle Centre Radius 4rc Centre Start End Arc Three Points Fillet Ellipsoid Bezier
53. position and orientation as it appears in 2D Design Now Select File CNC Output E TechSoft Design Tools 2D Design V2 Fr 20 wie Edit Draw Bitmaps View Setup Window D New Ctrl Ta Open Chrl 0 A Add er Lay Close Save Chrl 5 Save As Import File Export File Open Font Manage TechSoft Fonts Print Chril P Frink Setup Frink Options Print Silhouette Preview Silhouette CNC Output CHC Offset 1 Completed Frame dtd 2 Frame TEMPLATE dtd Exit The following dialogue will appear CNC Output Eg CNC device RotolahMh MDY 40 Tools Output Route Through printer diver Roland MDe 40 Change Driver Output Range Rotated Use Operation Panel to set 20 Fit C Selection Tile fe All Qutput to file Fill settings Cancel Help Make sure the device and print driver are set to Roland MDX 40 and select Output tf Galway Education Centre 29 CNC Routing The next step will involve setting the length of the tool on the machine Tool Set Point Check Change the Tool Set Point 5 00mm 30 Move to Tool Set Point t Imperial O oere Output Cancel Help MAKE SURE THAT THE TOOL IS NOT FITTED TO THE MACHINE AS IT MAY COLLIDE WITH THE WORKPIECE DURING THE NEXT STEP To set the tool click on the Move to tool set point button The tool will move to the coordinates shown in the X Y and Z
54. r second The control will output the pulse train to achieve this which is then amplified and delivered to the motor The stepping motor will travel the specified number of pulses and then hold in position until the next action The control has no way of knowing whether the motor has actually received or travelled the full distance Errors can occur if the motor misses a pulse or if it encounters an obstacle that causes it to stall Pulse Train to Stepping Motor i lad I Calculate Interpret axis Amplify position and transmit and to generate pulse train program stepper Figure 38 Open loop control system 72 tf Galway Education Centre CNC Routing This is not usually a problem where the forces acting on the stepping motor are low or where extreme accuracy is not critical The advantage of open loop is its low cost and simplicity Closed Loop Control This method of control has one additional element Servo motors are used to drive the axes and an encoder is used to provide feedback of the servo position to the control This allows the control to compare the actual position of the axis to where it should be at a rate of about 500 times per second Axis Position 1 i A Wo o F we Er oe Y fe i r Pir P 4 i i r onal 4 i a k 1 p W ria 7 n r of p a F Control Unit Figure 39 Elements of a closed loop control system The control outputs a voltage in proportion to t
55. roducing components that would otherwise be marked cut and filed to size It allows intricate parts to be cut that would otherwise be very difficult to manufacture Laser offers an attractive alternative to milling for acrylic or wood based materials Figure 2 Laser cut parts from Acrylic 2 Laser Engraving It is possible to take an image such as a photograph or other graphical image and engrave it onto wood or plastic using a slightly different machine setting than that used for cutting The quality of the image produced is very good Figure 3 Laser engraved image onto clear acrylic 2 t t Galway Education Centre CNC Routing CNC Routers Mills A router can be classed as a type of milling machine that allows very fast cutter travel combined with very high spindle speeds However routers have a relatively low stiffness compared with a conventional machine These machines are ideal for machining plastics wood modelling foam etc but usually are limited to non ferrous metals at best due to the lack of rigidity A desktop router typically comes with an impressive set of software and ancillary equipment considering the low cost They are extremely versatile and can be used for a variety of purposes A typical machine will offer the following capabilities 2 D Profile Cutting CNC routers can be used to machine shapes consisting of lines arcs and curves from sheet material The machine is usually driven by a 2 D machining
56. shapes were very difficult to machine by conventional processes and the first Numerical Control NC milling machines were developed for this purpose The machines had what is known as a hard wired control system and were capable of moving from one point to another in a straight line only The programs were generated using a computer and loaded into the machine control one line at a time using punched paper tape The programs consisted of long lists of coordinate data that were fed to the control one line at a time for each move This type of Ot Galway Education Centre 65 CNC Routing control did not have a computer and all of the control was achieved by the hard wired circuitry of the control system The machines were very expensive very large and used almost exclusively by the aerospace industry CNC The next major development came in 1975 with the advent of Computer Numerical Control Computer Numerical Control uses a computer to perform the tasks formerly done by the hardwired system They machines were much more flexible in operation It was now possible to machine an arc by issuing a single command as the control could now calculate all of the intermediate points along the arc CNC also featured canned cycles where the drilling of a hole or the cutting of a thread on a lathe could be simplified to a single command It was around this time that CNC started to become commonplace and CNC lathes and Milling machines were use
57. specialism involved However they are easy to use and can produce spectacular results Each is discussed in more detail below Engraving Engraving is a means of creating reliefs raised engravings and engravings on flat and curved surfaces Items such as text or a 2 D profile are given a thickness and then projected onto the surface of the object to be machined ltems such as text or line drawings are commonly used to make engravings Engravings can be made on existing solid objects if the surface of the object to be engraved can be captured using a 3 D scanner see above beforehand Images can also be engraved onto surfaces generated in CAD l Figure 11 Relief on a curved surface Lithopane Machining A Lithopane is a special form of image where a greyscale can be reproduced by machining a translucent material to varying depths The deeper the cut the thinner the remaining material and the more light that can pass through it By varying the depth of cut lighter and darker areas can be produced When lit from behind the image is visible High quality monochrome images can be produced in this way t Galway Education Centre 7 CNC Routing Figure 12 Lithopane machined from translucent plastic back lit and mounted in a frame Lithopane machining Is very easy to do using the specialist software accompanying Denford and TechSoft routers It involves taking a scanned image or digital photograph converting it to a gr
58. sting one As the tool has a diameter of 2 0 mm an offset distance of half that amount is used When finished the profiles should look like this 52 t Galway Education Centre CNC Routing Next select the colour BLUE and create a series of profiles to machine out the pocket The remaining operation is to engrave the text As the tool path coincides with the existing geometry it can be obtained by simply changing the colour First use the Select tool to highlight the geometry Then change the line colour to Blue The profile will be cut with the toolpath on centre of the blue profiles This completes the tool assignments for the profile The final step is to create output to the machine The physical setting of the tools is included in this stage t Galway Education Centre 53 CNC Routing Appendix 3 Cutting a part on the TechSoft Machine Fit the workpiece material to the machine table and Select File CNC Output E TechSoft Design Tools 2D Design V2 Fr S005 Edit Draw Bitmaps View Setup Window E Hew Ctrl N Ta Open Chrl a AH Add er Lay Close e Save Ctrl 5 Save Os Import File Export File Open Font Manage TechSoft Fonts Print Ctrl P Frink Setup Print Options Print Silhouette Preview Silhouette CAL Qutput Cbrl L CNC Offset 1 Completed Frame dtd 2 Frame TEMPLATE dtd Exit The following dialogue
59. ting Now drag and rotate any of the components to a different position on the PCB note the rotate icons are the two visible above the pull down menu in the figure above It should be possible to position the components so that their layout on the PCB is similar to the circuit diagram Make sure that the there is adequate space between the tracks and pads for the cutter to pass between them If not reposition them until a satisfactory result is achieved Save the file once you are happy with the layout Individual tracks can be moved by clicking and dragging on the nodes at the end of each segment The width of a track can be changed by right clicking on it and altering the properties Note that intervention such as this is usually not necessary with simple designs such as this one but it will sometimes be necessary to reduce the width of a track to pass underneath an IC or to re route it around an obstacle on the PCB with more complex designs Use Undo if necessary to revert to the correct design before proceeding to next section 36 tf Galway Education Centre CNC Routing Importing the data from Circuit Wizard to PCB Design and Make Transferring the data between the two systems does not require the use of Gerber files as it is possible cut and paste the design directly Start both applications and open the PCB design in Circuit Wizard Circuit Wizard PCB for project cwz ED Fie Edit View Project Window Hel
60. used to create the toolpath for all the through cut profiles The colour blue will be used to create an additional pass to give a recess around the aperture of the frame First choose RED as the drawing colour from the menu at the top of the screen NB Choose the red colour from the custom colours at the bottom of the palette This is because an exact match of the colour is needed Otherwise the geometry will be ignored when cutting Line Colour Basic colors m M Bee E O nnan ngn E O fee EgE EERE Ee EERE BE Custom colors EEeaEEe hUe E i go ustom Colors gt gt Now select the contour tool and set the offset distance to half the radius of the tool 1 00mm in this case Contour Settings Contour Spacing D mm Mas Number of Contours f Tool Path C Graphical Path Cancel Help t Galway Education Centre 21 CNC Routing Create contours to the outside of the outer profile and inside all the others as shown below The next step is to create a recess around the picture area In this case it will be sufficient for the centreline of the cutter to follow the existing shape of the opening The 2mm cutter 0 5mm depth defined earlier will be used Select the black rectangle that defines the opening of the frame and change its colour to BLUE 28 et t Galway Education Centre CNC Routing The part is now ready for machining Fix the material blank to the machine table in the same
61. will appear CHC Output CHC device Output Route Through printer driver Fioland MDv 40 Change Driver Output Range Rotated Use Operation Panel to set 20 fe All Fit C Selection Tile Output to file Fill settings Cancel Help The buttons provide access to the same settings that were set up at the start As these are already taken care of select Tools to move on to the tool setting 54 t Galway Education Centre CNC Routing Tool Set Point Checkichange the tool settings a 5 0mm Y 5 00mm Z 2 0mm Move to tool set point cao Hen MAKE SURE THAT THE TOOL IS NOT FITTED TO THE MACHINE AS IT MAY COLLIDE WITH THE WORKPIECE DURING THE NEXT STEP To set the tool click on the Move to tool set point button The tool will move to the coordinates shown in the X Y and Z boxes Enter a value of about 90mm in the Z box and press the button again This will move the Z Axis to a closer position to the table Now fit the cutting tool loosely and let it drop down to touch the top of the workpiece Tighten the upper collet so that it acts as a stop to set the tool length If the program uses more than one tool remove the tool and repeat for the other tools This has the effect of setting both tools to the same length Fit the correct tool and press the Plot button The following window will appear Tool Change Instructions PUWPORDANT F HRAST WAIT until machine has moved to the to
62. y its position along two or more of the machine axes An axis is can be considered as a degree of freedom or a direction along which the tool can move and roughly corresponds to the cartesian coordinates x and y used in CAD With CNC the situation is a little more complex however as explained below Axis Orientation The axes of a CNC machine are defined by what is known as the right hand rule If we take the thumb as pointing in the direction of the positive X Axis then the second finger is pointing towards the positive Y Axis and the middle finger towards the positive Z Axis The Z Axis always contains the spindle This holds true for all machine tools including lathes X Figure 32 The right hand rule 68 Ot Galway Education Centre CNC Routing Figure 33 Axis orientation for Router Figure 34 Axis orientation for Lathe Note that the right hand rule applies here also CNC machines are often described by the number of axes that are controlled A laser cutter would be classed as a 2 Axis device as motion is only controlled in the X and Y axes A CNC lathe is a 2 Axis where the tool is driven along the Z and X axes A router would be a 3 Axis machine as motion is possible in X Y and Z axes tf Galway Education Centre 69 CNC Routing Beyond Three Axis Control With some machines it is possible to fit a dividing head and or rotary table to provide rotary motion of the workpiece In this case the motion is considere

Notes on Miller/Router - Technsoft

Contents

Download Pdf Manuals

Related Search

Related Contents