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1. By executing the above program a plate with less than 0 2 mm thickness is generated It is so thin because each layer consists of only a single wind of filament The thickness of printed plate will be more than 0 2 mm because it is equal to the filament diameter The OpenSCAD window after the execution is shown in Figure 9 eee Angle 15 Ri 10 R2 R1 20 cos Angle OpenSCAD ThinDish scad H 20 sin CAngle differenced cylinder Ch H ri R1 r2 R2 fn 180 transLlate 0 2 cylinder h H r1 R1 r2 R2 fn 180 a Parsing design AST generation Compiling design CSG Tree ea ompilation finished Compiling design CSG Products generation g Viewport translate 0 00 0 00 0 00 J rotate 81 60 0 00 19 40 distance 500 00 Bam Figure 9 OpenSCAD window after executing the program When using OpenSCAD 3D models are represented by programs and can be stored or modified freely but they can also be stored in STL format which are execution Not yet published in conferences or journals results The STL file of the plate shown in Figure 9 can be downloaded from http www kanadas com weblog ThinDish15 stl or http bit ly 174wxfR Because OpenSCAD cannot display shapes very clearly a free software tool called netfabb Basic OpenSCAD was used for displaying the plate in Figure 10 A slicer can convert this STL file to a G code program that can be2. There must be other much more interesting methods Why don t you try one a When the gradient is 15 b When the gradient is 30 Figure 15 Printed plate with 30 gradient and 45 gradient by Slic3r References 1 Kanada Y 3D printing of Generative Art by using Combination and Deformation of Direction specified 3D Parts 4th International Conference on Additive Manufacturing and Bio Manufacturing ICAM BM 2014 Beijing 2014 11 http bit ly 1z 7eMCaO 2 Kanada Y Method of Designing Partitioning and Printing 3D Objects with Specified Printing Direction 2014 International Symposium on Flexible Automation ISFA 2014 2014 7 http bit ly lEqhV5d 3 OpenSCAD User Manual WikiBooks http en wikibooks org wiki OpenSCAD User Manua 1 4 Kanada Y Assembling and adjusting a cheap 3D printer Printrbot sweat and tears Japanese Edition Kindle version Dasyn com http www amazon com dp BOOD5D YME4 Not yet published in conferences or journals
3. The first step is that by changing the configuration of the slicer the amount of filament is increased There are various slicers available but Slic3r and Skeinforge are selected as representatives here Both programs are widely used for 3D printing The methods for increasing filament depend on the program Slic3r works better for printing a plate When using Slic3r the value of parameter called extrusion multiplier should be set to between 4 to 6 instead of normal value around 1 0 This means the amount of filament is 4 to 6 times larger Figure 6 a shows the configurations for Slic3r The value of extrusion multiplier is set to 6 in the configuration window of filament for Slic3r for Macintosh In this window the following parameters are also specified the thickness of filament 1 75 mm the temperature of extruding filament about 200 C for PLA of good quality and the temperature of print bed 1 e the surface to start printing 30 C a temperature that PLA fits well to the print bed Figure 6 b shows the configurations for Skeinforge The value of filament packing density is set to 0 15 to 0 25 instead of normal value around 1 0 This means that the filament is increased 1 0 25 to 1 0 15 times This figure shows that 0 25 is specified for Skeinforge for Macintosh If you use another slicer you should follow the own style of the slicer m Slic3r Plater Print Settings Printer Settings config ini
4. Yes Actually there is a method to enable it The next section introduces this method 3 Problems of printing plates and a solution 3 1 Problems of conventional 3D printing The problem of conventional 3D printing of plates are as written above is that it is not possible to print it without support Figure 5 shows what happens when printing it without support Figure 5 a shows what happens when the direction of overhang and filament direction are orthogonal The filaments drop down in this case Figure 5 b shows what happens when the direction of overhang and filament direction are parallel The filament bends downward in this case Not yet published in conferences or journals v a When the filament is orthogonal to overhang direction filament drop down Figure 5 Problems of 3D printing with high angle overhang b When the filament is parallel to overhang direction filament bending 3 2 Outline of the solution How can we solve the above explained problem when printing a plate The solution is in short to increase the amount of filament so that printed filament becomes thicker and sticks to the neighbor filament Normally if the layer thickness is 0 2 mm the thickness of filament is set to a slightly larger than 0 2 mm However in this case for example it is set to 0 4 mm It makes neighbor filaments stick together This solution is explained more in the following 3 3 Setting filament increase
5. a and G code that represents plate and support b Support is disposed after printing so it 1s wasteful The support in Figure 2 b can be smaller but it may sometimes use more material than plate itself For displaying G code in this figure Repetier Host Macintosh version is used Is there a method for shaping plates without support that wastes plastic It is difficult while using conventional 3D printing methods However there are two methods that enable it The next two sections introduce them 2 Shaping plates by helical printing method A model to be printed is sliced into thin layers and they are printed one by one in conventional 3D printing methods A seam is generated when transiting from one layer to the next layer Such seams are highly visible when printing a thin object such as a plate b With support Figure 2 Visualized G code Seams can be eliminated by printing helically instead of layer by layer The helical printing method Reference 1 enables this This method not only eliminates seams but also enables free 1 e non horizontal printing directions This enables the direction of filament extrusion expresses shape formation Reference 2 However it is out of scope of this article Figure 3 shows a plate printed by the helical printing method Because this plate is made of transparent PLA and the printing direction and gradient of each part is designed to light reflection to a different direct
6. of filament is four times as much as required at the bottom However the bottom still seems to be good a When using Slic3r b When using Skeinforge Figure 12 Printed plate with 15 gradient round layer height 0 15 mm The major problem in these print results is the layer seam You can probably see the seam in the left side in both Figures 12 a and 12 b but they are not very clear So Figure 13 zooms into the seam Especially in Figure 13 b i e in the case of Skeinforge several gaps that spoil the plate can be observed around the seam but they can also be observed in Figure 13 a in the case of Slic3r Compared with the helical printing method in which no such seams or gaps are generated they can be regarded as a fatal defect However it is probably possible to conceal them by using an advanced method I have not yet tried but why don t you try to print a better plate In addition you can probably more easily see that the filament arrangement array is better for Slic3r by this figure The asperity had become smaller except the seams when the layer height is set to 0 135 mm Figure 14 shows a photo of a plate using Slic3r The estimated filament diameter is still 0 50 mm but the seams have become bumpier Although this plate seems to have Not yet published in conferences or journals holes in this photo but it just reflects light and it does not have holes In addition although the holes cannot be o
7. Not yet published in conferences or journals 3D printing plates without support Yasusi Kanada Dasyn com When printing a plate dish using a 3D printer normally so called support material which is disposed after printing is required to be printed and to support the plate However try to create thin plates without using such superfluous material Some devices are required to print them but it 1s not so difficult 1 Printing plates by a conventional method When creating something by using a 3D printer first we design it by a computer aided design CAD software tool and generate a model The model is represented by a language format called STL The model is sliced into thin layers and divided into strings and translated into G code which is a language format used for 3D printers The above process makes the design printable A type of 3D printer that layers melted plastic such as ABS or PLA is called fused deposition modeling FDM type printer An FDM type printer melts plastic into strings filaments and layers them according to a G code program Figure 1 Figure 1 Process of FDM type 3D printing FDM by Zureks by Zureks Wikimedia Commons When printing a plate by using an FDM type printer by a conventional 3D printing method round or overhung part of the plate must be supported by printed material that is called support Figure 2 visualizes G code that represents plate only
8. bserved there is a large hole between the bottom and the round part The bottom should be thicker e g consists of three or more layers by changing the design a When using Slic3r b When using Skeinforge Figure 13 Layer seams of printed plate layer height 0 15 mm Figure 14 Printed plate with 15 gradient round layer height 0 135 mm using Slic3r In addition Figure 15 shows the results of printing plates with 30 and 45 gradient round In both cases Slic3r was used The layer height was 0 25 mm and the extrusion multiplier was 2 5 for the former and the layer height was 0 35 mm and the extrusion multiplier was 1 5 for the latter Both are well printed except the seams 6 Concluding Remarks 3D printers are widely used and studied in companies in Japan Especially FDM type printers gradually become familiar to personal users Although few personal users have their own 3D printers they can use 3D printers by rentals in FabLab or DMM MAKE Most of people who use 3D printers use CAD tools in the conventional method However there must be many more different ways to use 3D printers 1 e different printing methods design methods and so on This article showed that a new method for printing a plate without support As described in Section 2 I tried a completely different method called the helical printing method but the method introduced in this article 1s a compromised method 1 e pseudo layered method
9. executed printed by a 3D printer ae ee S Figure 10 A plate designed by OpenSCAD displayed by using netfabb Basic 5 Let s print the plate Now let s print the designed plate I use a 3D printer called Rostock MAX Figure 11 but any other types of 3D printer can be used for this purpose The nozzle diameter of my printer is 0 5 mm The time required for printing the plate 1s about 6 minutes However to shorten the printing time the printing speed may have to be changed by changing the configuration of the slicer Ia Figure 11 My 3D printer used for printing plates Rostock MAX Figure 12 shows photos of the results of printing plates with 15 gradient round by using Slic3r a and Skeinforge b The layer height is 0 15 mm which is relatively thicker because the estimated filament diameter is 0 56 mm much larger than 0 4 mm The amount of filament is four times as much as the original value However the amount of filament is still smaller than the theoretical value that is the calculated diameter is less than 0 56 This is a mystery The photos seem to show both worked well but actually the filaments draw more exact concentric circles in the case of Slic3r In addition maybe because the layer height is too large the stability of printing seemed to be low and small scale asperity exists in this case Because the amount of filament is tuned to the round with 15 gradient the amount
10. icing Extra perimeters if needed Avoid crossing perimeters antacas Version 1 1 7 Remember to check for updates at http slic3r org a When using Slic3r f 7 eee thickDish stl Skeinforge Settings Profile Type Extrusion Profile Selection PLA Analyze Craft Help Meta Profile Craft Alteration Bottom Carve Chamber Clip Comb Cool Dimension Dwindle Export Fill Fillet Home Hop Inset Jitter Lash Limit Multiply Oozebane Preface Raft Scale Skin Skirt Smooth Speed Splodge Stretch Temperature Tower Unpause Widen Wipe Carve Add Layer Template to SVG Edge Width over Height ratio py E Extra Decimal Places float 2 0 Import Coarseness ratio 1 0 v Layer Height mm E C Layers Layers From index 0 l omanan To Lien ol meds NANN ACEC IO Skeinforge Cancel Save All b When using Skeinforge Figure 8 Configuration change of slicer for specifying layer height 4 Let s design plates Now let s design a plate to be printed by using a CAD software tool That is an STL file is prepared Any CAD program can be used but OpenSCAD Reference 3 which is a free software tool is used for example here A Japanese Kindle book Reference 4 explains all the programs including OpenSCAD used in this article Many CAD programs use graphical user interface GUI to create 3D models However a model is generated by a program by using OpenSCAD This method takes more time when crea
11. ion the plate reflects light to various directions and gives brilliance Support which spoils brilliance is not used for this plate Figure 3 A small plate printed by the helical printing method The process of printing a plate by the helical printing method can be observed by a video in YouTube http youtu be 5PlvaahzW98 Highly transparent PLA is not usually used in 3D printing However pure PLA such as PLAGO has high degree of transparency and it is very attractive as filament for this type of 3D printing More than ten types of small plates are sold at around 150 yen in Dasyn shop in Yahoo shopping http store shopping yahoo co jp dasyn or http bit ly 1EZ4SZI This shop sells various goods that include a transparent and empty globe shown in Figure 4 A more advanced printing technique is used in this globe so the author will introduce it in another opportunity Hy j MN I O nS _ i i i wi Figure 4 A small globe printed by the helical printing method The design method for the helical printing method is different from that of the conventional 3D printing method So although conventional 3D printers can be used for this method currently it cannot be applied to models designed by conventional CAD software tools Then is it not possible to print plates without support by using a software tool for conventional 3D printers
12. modified Filament d Filament Diameter 1 75 Cooling Extrusion multiplier 6 Temperature C Extruder First layer 200 2 Other layers 200 lt Bed First layer 30 2 Other layers 30 Version 1 1 7 Remember to check for updates at http slic3r org a Slic3r changing extrusion multiplier eee thickDish stl Skeinforge Settings Profile Type Extrusion Profile Selection PLA _ Analyze Craft Help Meta Profile Craft Alteration Bottom Carve Chamber Clip Comb Cool Dimension Dwindle Export Fill Fillet Home Hop Inset Jitter Lash Limit Multiply Oozebane Preface Raft Scale Skin Skirt Smooth Speed Splodge Stretch Temperature Tower Unpause Widen Wipe Dimension Activate Dimension Extrusion Distance Format Choice fe Absolute Extrusion Distance Relative Extrusion Distance Extruder Retraction Speed mm s a Filament Filament Diameter mm 1 75 a Filament Packing Density ratio 02 Skeinforge 2 Cancel Save All b Skeinforge changing filament packing density Figure 6 Slicer configuration change for increasing filament 3 4 Configuration change of layer height The next step is to change the configuration of the slicer to adjust the layer height The layer height is usually smaller than the diameter of the nozzle which extrudes melted plastic The nozzle diameter is usually 0 3 to 0 5 mm If the diameter is 0 5 mm normal layer height is for example 0 4 mm Howeve
13. r the layer height is set to smaller value here The reason why layer height should be smaller is explained as follows Figure 7 shows part of a cross section of a plate It is assumed that the filament is wound with the angle of 15 from the horizontal surface If the diameter of the filament is 0 4 mm or slightly larger the difference of the heights from the neighbor filament is 0 4 sin 15 0 1 mm The layer height should thus be 0 1 mm However because the filament location that the slicer chooses may be different so the height may have to be adjusted Figure 8 shows two windows for specifying the layer height 1 e Slic3r a and Skeinforge b The layer height is 0 1 mm for both but the first layer height is also set to 0 2 mm for Slic3r This is because if the height of the bottom layer is 0 1 mm too it becomes difficult to adjust the printer for successful printing Not yet published in conferences or journals ae 0 4 cos 15 0 39 mm of asee of Figure 7 Decision of layer height eee Slic3r Plater PADE Filament Settings Printer Settings config modified __Layer height T Layers and perimeters Layer height 0 1 mm Infill First layer height mm or J Speed Skirt and brim Vertical shells i Support material El Notes Perimeters minimum 3 M Output options Spiral vase Multiple Extruders 7 Advanced Horizontal shells Solid layers Top 3 gt Bottom 3 S Quality slower sl
14. ting a model at first 1 e writing a program but once the program is created it has an advantage that it is easier to modify the model program I am relatively accustomed to draw a two dimensional shape such as shown in Figure 5 or 7 by using a program such as Microsoft PowerPoint the method of drawing 3D shapes by using a CAD program is usually quite different so I am not accustomed to it Therefore I prefer to use OpenSCAD Many different methods can be used for drawing a plate by using OpenSCAD but a relatively easy method is to use a cylinder with different sizes of top and bottom surfaces That is to use the following program The mostly the same program is available at http www kanadas com weblog 2015 02 cad html or http bit ly 173UG6b Angle 15 R1 10 R2 R1 20 cos Angle H 20 sin Angle difference cylinder h H r1 R1 r2 R2 fn 180 translate 0 0 0 2 cylinder h H r1 R1 r2 R2 fn 180 In this program an expression cylinder h H r1 R1 r2 R2 fn 180 occurs twice This expression represents a cylinder with the radius of the lower base is R1 and that of the upper base is R2 i e a plate filled with something like water One of the cylinders is placed 0 2 mm upper direction than the other by translate 0 0 0 2 The upper cylinder is subtracted from the lower cylinder by difference so that the shape becomes a plate without water
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