Xcavator Instruction Manual
Contents
1. Xcavator User Manual Patent Pending Proudly Made in the U S A BEZ Whip Mix Corporation 361 Farmington Ave P O Box 17183 Louisville KY 40217 0183 USA 502 637 1451 800 626 5651 Fax 502 634 4512 www whipmix com Xcavator Operating Instructions Intended Purpose The Whip Mix Xcavator is designed to automatically remove 9596 of the volume of investment mold material surrounding pressed ceramic restorations where manual divestment would typically be done When used as directed the unit will significantly shorten the total process time required to go from press oven removal to pattern retrieval The unit can be run unattended and will alert the operator when an investment mold is divested to allow efficient processing and labor usage The unit employs state of the art robotic precision to ensure consistent material removal time after time The Xcavator is easy to operate ergonomically friendly and compact enough to earn its place on a work surface in the casting room Important Topics for Safe Reliable Operation Grounding The high velocity flow of glass beads across plastic or metal surfaces will charge the beads and the surfaces they flow over Great pains have been taken to ground every component in the Xcavator to insure equalization of static electrical charges The power cord and the outlet the unit is plugged into must have 3 prongs to insure the presence of the earth ground which is vital to the p2. You can compensate for the reduced depth of cut by increasing the knob setting by one click clockwise The maximum recommended gap between the end of the cutting tip and the top of the investment mold should not exceed 5 16 of an inch or else the outer wall of the investment mold will be penetrated and this will significantly alter the flatness of the floor of the resulting divested area See below Wand Too Close Leaves Partitions OUTER WALL I DESIRED TO YIELD A FLAT FLOOR Wand Too Far Penetrates Outer Wall And Creates a Hump OUTER WALL MISSING LEADS TO THE DOMED HUMP Diagnosing Non Cutting Issues No Ready ldle Indication If the Ready ldle indicator is off AND one of the cycle indicators is lit press the Abort key which should cause the cycle indicator to first extinguish then after a few seconds and the swing arm going to the rear most park position the Ready Idle indicator should light If the Ready ldle indicator is off AND the Exhaust Flow is off please see Vacuum Fault Indication below If the Ready ldle indicator is off AND no other indicators are lit please see No Indicators Lit below Vacuum Fault Indication If the Vacuum indicator is lit even when connected to a running vacuum source place your hand over the exhaust port inside the cabinet You should feel moderate suction If not check the filter bag in your exhaust system If you still do not get the Exhaust Flow
3. decreasing linearly to 50 relative humidity at 35 C 104 F Pollution Degree 1 Installation Category 2 Divestment Times Packing List Selector 100 gm 200 gm The tolowing 0 Position Cycle Time Cycle Time were shipped with your order 0 251mi 551min 1 Xcavator Assembly 5 100 Gram Chuck Assembly 1 284mi 578min 2 AC Power Cord 6 200 Gram Chuck Assembly 2 277mm 6 07 min _ 3 Strainer 7 Bead Dryer Belt 38 292mm 6 40 min 4 Brush 2 inch 4 80800 676min T Description Item Xcavator Automated Divesting Unit 09800 3 71 min za Replacement Parts List 5332 Pen With Tubing Assembly 10 28 min Hand 1 19 mi MELIA 5356 Reservoir Gasket 12 35 min 13 78 min 5303 Clear Shield 15 57 min 45353 Strainer 15 17 91 min Reservoir Bead Consumption Bead consumption will vary significantly according to LE e Bead size e Concentration percentage of the special liquid in the investment mold hardness e Depth of cut knob setting Bead Dryer Belt Technical Support Call 800 626 5651 19 09807 09813 09819 09821 09809 09811 09823 09825 09827 09829 09805 09806 MPL5300 12 11
4. NOT SITTING FLAT IN THE GROOVE REPEAT THE PROCESS UNTIL IT IS FLAT IF THERE ARE STILL WAVES OR BULGES IN THE GASKET REPLACE IT WITH A NEW GASKET Xcavator Operating Instructions Maintenance continued Nozzle Tip O Ring Cleaning and Replacement Over time bead fragments and dust can worm their way around the O Ring and cause air to escape from the Wand which is one of the two primary reasons for loss of cutting depth The other reason is the Lid O Ring This simple procedure can be quickly performed to restore the proper cutting depth Unscrew the Nozzle Cap 1 in the pictorial and remove the small O Ring 2 in the pictorial Clean any dust or grit from the O Ring with a dry cloth NEVER USE WATER OR ANY OTHER LIQUID TO CLEAN THE O RING AS IT WILL PROMOTE BEAD CLUMPING THE O RING WILL HAVE A FLATTENED SHAPE WHEN REMOVED BUT WILL SPRING BACK INTO A DONUT SHAPE AFTER A COUPLE OF MINUTES THIS IS ENTIRELY NORMAL Clean the Nozzle Cap interior by blowing it out or wiping with a Q tip or other dry material Reassemble in the order shown in the pictorial Tighten the Nozzle Cap moderately The O Ring should be changed monthly There are 12 spare O Rings in the accessory box enough to last 1 year Additional packages of 12 may be re ordered with item 5 part number shown at right Nozzle Replacement The nozzle should give at least 6 months of service under moderate usage 8 10 rings day You can tell when the noz
5. UNTIL THE READY LIGHT TURNS GREEN AND THE BEEPER BEEPS OPENING THE CABINET PREMATURELY BEFORE THE BEEPER CAN ALLOW HAZARDOUS DUST PARTICLES TO ESCAPE INTO THE ROOM Step 11 Open the door and remove the 95 divested mold by hand as it will now be cool enough to handle safely with your bare hand Figures 10 Step 12 Use your manual divester briefly if necessary to remove any material shadowed by the sprue arms or inside the hollows of the copings Figure 10 Xcavator Operating Instructions Maintenance Maintenance Schedule Suggested Frequency Weekly General Cleaning The inside of the plastic shield may become statically charged and coat over with dust from time to time Use a clean damp cloth or paper towel to wipe it clean The cabinet exterior may be cleaned with a damp cloth Excess bead investment debris inside the unit may be swept into the slot opening inside the cabinet using the brush provided with the Xcavator When the drawer below becomes full it can be removed by pulling it towards you support underneath with your other hand and fully withdraw from the cabinet for transport to a recycling unit or disposal container AIR REGULATOR RING PUSH RING UP TO OPEN VALVE TO RELEASE WATER ACCUMULATION WATER This plastic bowl should be checked weekly to see if moisture has accumulated If it has moisture you can drain it by grasping the black plastic ring underneath the clear bo
6. may be harder than glass beads and damage the porcelain work product 2 Other material sizes may alter the depth of cut and or the cut channel width IMPORTANT NOTE THE XCAVATOR PRODUCT HAS BEEN EXHAUSTIVELY TESTED WITH WHIP MIX BRAND 50 MICRON GLASS BEAD MEDIA FOR BEST AND MOST RELIABLE DIVESTING RESULTS WE STRONGLY RECOMMEND YOU USE WHIP MIX BRAND BEADS WHIP MIX BEADS FLOW MORE RELIABLY AND ARE LESS PRONE TO CLUMPING DURING HIGH HUMIDITY CONDITIONS THE USE OF ALUMINUM OXIDE ALOX BEADS IS NOT RECOMMENDED FOR USE WITH THE XCAVATOR ALOX BEADS WILL POTENTIALLY CAUSE DAMAGE TO YOUR PORCELAIN BECAUSE THEY ARE HARDER THAN THE PORCELAIN ALOX WILL ALSO CAUSE PREMATURE WEARING OUT OF THE QUARTZ NOZZLE Xcavator Operating Instructions Familiarization Access Door a Control Panel Ready indicator 4 2 3 4 5 6 7 8 100 Gram cycle start key cool mold 200 Gram cycle start key cool mold 100 Gram time delay before start indicator hot mold 200 Gram time delay before start indicator hot mold Abort cycle key Exhaust flow Indicator Depth of cut selector switch Setup Air Supply 1 Connect your compressed air supply to the air regulator inlet hole shown in the photograph Figures 1A and 1B The inlet hole is a standard 1 8 National Pipe Thread NPT Air Regulator Setpoint Adjust 2 With air supply connected pull knob upward and rotate it until gauge needle points to 35 psi F
7. RESERVOIR AND CAUSE TRANSFER PROBLEMS Xcavator Operating Instructions Filling Jar IMPORTANT NOTE a THE XCAVATOR PRODUCT HAS BEEN EXHAUSTIVELY TESTED WITH WHIP MIX BRAND 50 MICRON GLASS BEAD MEDIA FOR BEST AND MOST RELIABLE DIVESTING RESULTS WE STRONGLY RECOMMEND YOU USE WHIP MIX BRAND BEADS WHIP MIX BEADS FLOW MORE RELIABLY AND ARE LESS PRONE TO CLUMPING DURING HIGH HUMIDITY CONDITIONS THE USE OF ALUMINUM OXIDE ALOX BEADS IS NOT RECOMMENDED FOR USE WITH THE XCAVATOR ALOX BEADS WILL POTENTIALLY CAUSE DAMAGE TO YOUR PORCELAIN BECAUSE THEY ARE HARDER THAN THE PORCELAIN ALOX WILL ALSO CAUSE PREMATURE WEARING OUT OF THE QUARTZ NOZZLE 1 Remove the lid of the reservoir by rotating it by hand counter clockwise Place the strainer over the rim of the reservoir and pour the new beads into the strainer slowly allowing time for the beads to pass through Figure 10 Always use the strainer when filling the jar to eliminate clusters of beads which will cause the unit to malfunction Enclosed with your Xcavator Unit is an electric Bead Dryer Belt Fig 13 When plugged into a 110V socket the belt will warm the beads to prevent clumping due to moisture The belt will ensure that the beads flow through the strainer and transport reliably to the nozzle Fig 14 Fill the jar with 50 100 micron glass beads up to the maximum fill line on the jar then replace the jar lid by screwing it clockwise then snugging Figure 11 Figure 12 it
8. corresponding delay cycle button and the Xcavator will announce when the mold is 95 percent divested with a beeping sound and the green Ready light will be lit The divested mold will now be cool enough to remove from the Xcavator by hand and touchup the remaining 5 percent by hand in as little as 30 seconds The nozzle swing arm is also controlled by a robotic grade precision stepper motor to digitally position the nozzle along each concentric cutting track with minimal overlap and high repeatability An Important Note Regarding Air Pressure Even though the incoming air pressure is perhaps higher than you would normally select for manual divestment the direct comparison is not physically valid for the following reason when manually divesting the nozzle is within less than a centimeter of the glass pattern The Xcavator jet nozzle NEVER comes within 2 3 centimeters of the glass pattern and is in CONSTANT MOTION making it impossible to dwell over any given spot on the glass pattern for more than a few seconds The increased distance effectively drops the pressure level of the air propelling the beads so that by the time they reach the glass pattern the kinetic energy the beads transfer to the glass is actually less than with a manual divester You should use only one type and size of bead media In practice the only one of these interactive factors remaining variable should be the Depth of Cut Selector knob Xcavator Operating Instru
9. corresponding to the Investment type you use NOTE DATA MUST BE DERIVED FROM ACTUAL PRESSED RINGS AS THE HARDNESS OF THE RINGS INCREASES AFTER THE PRESSING HEAT x CYCLE TESTING BLANK MOLDS WHICH HAVE BEEN THROUGH THE BURNOUT CYCLE BUT NOT THE PRESSING HEAT CYCLE WILL GIVE MISLEADING RESULTS DUE TO THE HARDENING EFFECT OF THE PRESSING HEAT CYCLE Investment Type Investment Type Liquid Concentration Depth of Cut Setting 35 PSI Liquid Concentration Depth of Cut Setting 35 PSI Investment Type Investment Type Liquid Concentration Depth of Cut Setting 35 PSI Liquid Concentration Depth of Cut Setting 35 PSI Xcavator Operating Instructions Step By Step Directions For Use Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 Step 8 Know your material brand and mix concentration percentage Make sure there is at least 3 inches of bead media showing inside the reservoir to ensure completion of the current mold divestment Select the mold chuck size which corresponds to the ring size 100 gram or 200 gram Figure 1 Open the door on the Xcavator by swinging the handle towards you Figure 2 Insert the chuck onto the mounting plate Figure 3 Remove the freshly pressed hot mold from the pressing furnace Pick up the still hot mold with tongs and place it on the open door of the Xcavator momentarily with the press plunger facing up Figure 4 then reverse the forceps and re grip the mold as clos
10. ctions Before You Commission for Every Day Use CALIBRATE EACH BRAND OF INVESTMENT OVER THE RANGE OF CONCENTRATIONS YOU ARE USING We recommend you pour up some empty test molds for each Typical settings for Whip Mix Formula 1 Investment brand of investment you use at the minimum and maximum In order from the hardest to the softest liquid concentrations and burn them out then perform test divestments and record the spindle speed selector switch settings to bracket the lowest concentration least dense mold lower numbered speed settings and the highest density highest concentration mold When you are comfortable that you can span the entire range of mold densities you can fill in the intervening concentration values Air Pressure 35 psi on the regulator gauge Bead Media 50 micron to 100 micron pure glass beads Investment Type Whip Mix Formula 1 Liquid Concentration Depth of Cut Setting 10096 Switch Position 5 l 90 Switch Position 5 Again for the maximum protection of your work product and 8096 Switch Position 4 the most consistent results we recommend you keep the air pressure constant and utilize the Depth of Cut knob to alter 10 Switch Position 4 the spindle speed cycle time to yield the desired depth of cut We recommend that you calibrate your depth of cut to land in a horizontal plane midway between the bottom of the central glass button and the top of the glass button Fill in the data
11. d chuck assembly for each nominal mold size 100 amp 200 gram molds Figure 6 The chucks are easily exchanged as work load dictates Chuck Assembly Setup 2 Beforeusing the divester make sure the three thumbscrews are pre adjusted for the type of ring former system you use Figure 7 If you use tapered ring formers place a tapered investment mold in the chuck and adjust the thumbscrews inward until they contact the investment Then withdraw them one full turn to allow enough clearance for the hot mold to slip into the chuck without interference which might cause you to lose your grip on the ring with the tongs If you use both tapered and untapered rings of each size you will want to purchase additional chuck assemblies so that you don t have to constantly re adjust the thumb screws See spare parts list in back of manual Chuck Assembly Installation 3 Select one of the two furnished chuck assemblies 100 gram or 200 gram and place it over the two guide pins on the mounting plate inside the cabinet Figure 8 Figure 7 Figure 8 Checking Reservoir Gasket 1 Please note the gasket in the lid of the reservoir It is important to keep this gasket and the mating rim of the reservoir wiped free of beads to insure a good air pressure seal Figure 9 The threads in the lid should also be wiped with a DRY cloth or brush to remove beads accumulating in the threads CAUTION NEVER USE A WET CLOTH AS THE MOISTURE WILL GET INTO THE
12. e to the door as possible and flip the mold inverted so that the press plunger is now facing downward Place the mold on the three threaded screws inside the chuck assembly so that the mold is centered between the three posts Release the tongs and withdraw them Figure 5 Close the door by swinging the handle up and away from you The Ready ldle LED will be on signifying the unit is ready to begin divestment Figures 6 and 7 As long as the unit senses flow in the dust exhaust system CAUTION DO NOT DEFEAT THIS SAFETY FEATURE NOR OPERATE THE UNIT WITH THE DOOR OPEN THE DUST GIVEN OFF BY THE AIRBORNE INVESTMENT PARTICLES CAN BE HAZARDOUS TO YOUR HEALTH iai Figure 6 Figure 1 Figure 7 Xcavator Operating Instructions Step By Step Directions For Use continued Step9 Position the Depth of Cut Selector knob to the pre determined position for the type of investment and the concentration of the mix for the specific mold you just put in the Xcavator Figure 8 Step 10 Press the Delay button corresponding to the mold size you just put in the Xcavator You can go about other duties until the Xcavator beeps and the Ready LED lights Figure 9 NOTE IF THE MOLD HAS COOLED NATURALLY FOR MORE THAN 10 MINUTES YOU CAN BYPASS THE TIME Figure 8 DELAY FUNCTION BY PRESSING THE ACTIVE BUTTON FOR THE GIVEN RING MASS AND THE DIVESTING CYCLE WILL START IMMEDIATELY CAUTION DO NOT OPEN THE CABINET DOOR
13. f the investment mold platform is rotating during the cycle but you have either of the two removal patterns above then the cause is a lack of bead flow to the tip of the cutting wand Figure 2 The most likely cause for lack of continuous bead flow is an elevated moisture content in the beads This can happen in the bead storage bucket which is why it is important to keep the Bead Dryer Belt and plugged in to keep the beads warm enough to prevent moisture accumulation Make sure you plan ahead and add the Bead Dryer Belt to the bucket of beads the day before needed The Bead Dryer Belt is a low wattage heater and it will take 12 18 hours to warm the beads The best way to judge whether the beads have taken on moisture in the bead bucket is to observe how they flow through the grey plastic strainer as you refill the jar If they stack up on top of the mesh and you have to tap on the strainer to get them to flow through this is an indication of high moisture content Dry beads will flow through the strainer in a uniform flow within five seconds Note Non Whip Mix brand beads may flow through the strainer yet still stack within the bead jar The trick to keeping the beads dry is to make sure the storage temperature is five degrees or so above the room temperature this is the reason the Bead Dryer Belt is included with your Xcavator system An indication of high moisture content once the beads are in the jar can be seen when the unit i
14. firmly closed by hand Figures 11 and 12 IMPORTANT NEVER OVERFILL THE JAR AS THE BEADS REQUIRE AT LEAST A HALF INCH OF HEAD SPACE TO ALLOW ROOM FOR AERATING THE BEADS SO THAT THEY WILL TRANSFER CAUTION IF THE LID CANNOT BE REMOVED BY HAND AFTER THE UNIT HAS BEEN PRESSURIZED DURING A DIVESTMENT CYCLE MAKE SURE THE AIR FLOW NOISE HAS STOPPED AND ALLOW 30 SECONDS TO ALLOW ANY RESIDUAL AIR PRESSURE INSIDE THE JAR TO BLEED OFF THROUGH THE NOZZLE IF YOU CANNOT FEEL OR HEAR ANY AIR AT THE NOZZLE AND THE LID STILL WILL NOT RESPOND TO HAND LOOSENING Figure 13 Figure 14 CONSULT THE TROUBLESHOOTING SECTION AT THE REAR OF THIS MANUAL IMPORTANT NOTE IF THE BEAD MEDIA DOES NOT FLOW FREELY THROUGH THE STRAINER THIS IS AN INDICATION OF EXCESSIVE MOISTURE CONTENT MOIST BEADS WILL ADHERE TO EACH OTHER AND NOT FREELY SEPARATE FROM EACH OTHER AND FALL THROUGH THE STRAINER THEY WILL CAUSE INTERMITTENT OR EVEN COMPLETE STOPPAGE OF TRANSPORT FLOW TO THE JET NOZZLE THE BEAD DRYER BELT AROUND THE BEAD BUCKET WILL HELP PREVENT THIS MOISTURE ACCUMULATION Xcavator Operating Instructions Theory Of Operation The Xcavator is designed to remove 95 percent of investment material from a 100 gram or 200 gram investment mold unattended It will shorten the overall press to pattern recovery time significantly Instead of removing a hot mold from your pressing furnace and waiting up to 50 60 minutes for it to cool to a safe bare hand handli
15. igure 2 NOTE THIS MAY NEED TO BE RE ADJUSTED SLIGHTLY ONCE BEAD FLOW IS ESTABLISHED Push knob back downward after pressure is set Daily Moisture Bowl Check 3 Pressing upwards on the black plastic ring at the bottom of the air regulator opens up a check valve and allows accumulated moisture to drain from the clear plastic accumulator bowl Figure 3 It is very important to keep drained so that moisture does not pass through to the bead reservoir Moist beads will adhere to each other and prevent transfer to the nozzle Figure 2 Xcavator Operating Instructions Setup continued Exhaust Port 4 Connect your central vacuum system or dedicated vacuum unit to the rear of the cabinet as shown Figure 4 CAUTION NEVER OPERATE THE XCAVATOR UNIT WITHOUT SUCTION INSIDE THE CABINET TO PREVENT HUMAN EXPOSURE TO FINE PARTICULATE MATTER WHICH CAN BE HAZARDOUS TO YOUR HEALTH Power 5 Connect the furnished power cord to the unit and then to any grounded AC outlet capable of furnishing 15 amps standard branch breaker size Figure 5 NOTE POSITION THE UNIT LEAVING ENOUGH SPACE AROUND THE LEFT HAND SIDE OF THE CHASSIS SO YOU CAN EASILY REACH THE MAIN ON OFF SWITCH 6 Place Bead Dryer Belt around the middle of the bead container and plug into a 110V wall socket It will warm the beads to eliminate and prevent bead clumping due to moisture humidity Figure 4 Figure 5 Chuck Assemblies 1 There is a dedicate
16. indication pinch the sensor tubing to see if there is any blockage in the sensor line or remove the tubing and manually blow it clear of debris with an air jet Replace the tubing and press the Reset button The Exhaust Flow indicator should now be lit If not Call Technical Support Spindle Does Not Turn And Or Swing Arm Does Not Move But LEDs Lit 1 Check Cable Connections 2 Call Technical Support No Indicators Lit 1 Make Sure Outlet Has Power 2 Check Fuses 3 Call Technical Support Xcavator Operating Instructions Specifications Line Voltages 100 VAC 60 Hz Use Fuse Type 5 20 mm 2 Fuse Rating 2 0 Amps 115 120 VAC 60 Hz Use Fuse Type 5 20mm 2 Fuse Rating 2 0 Amps 208 240 VAC 50 Hz Use Fuse Type 5 20 mm 2 Fuse Rating 2 0 Amps Dimensions 19 25 in 48 9cm Height 14 5 in 36 9cm Width 15 5 in 39 4cm Depth Product Weight 29 Ib 13 1 kg Shipping Weight 36 Ib 16 3 kg Investment Mold 100 gram typically 1 4 inches in diameter by 2 inches tall 200 gram typically 2 2 inches in diameter by 2 inches tall Delayed Start Times 100 g Delay 6 25 min 200 g Delay 9 6 min Environmental Specifications Intended for indoor use within operational parameters Fluctuations of main power supply not to exceed 1096 of nominal voltage Altitude up to 2000 meters 6 560 ft Temperature 13 C to 41 C 55 F to 105 F Maximum relative humidity of 70 for temperatures up to 35 C 95 F
17. mmm SEAL ii 1 7 ammEan STREAM 4 AIR SOURCE 4 T 2 INVESTMENT l MOLD BRASS AW OLD BLOCK AIR VALVE AIR REGULATOR Reference the diagram above as you read the description below The air pressure is regulated to 35 psi in the air regulator and turned on and off in the air valve then passes into the brass manifold block where part of the air goes upward into the top of the bead jar and presses downward on the beads The rest of the air travels to the left in the diagram and gets mixed with beads in the bead injector The combined bead airstream exits the brass manifold block at the left in the diagram and travels via the black tubing to the wand and finally out the tip where the mixture collides with the top of the investment mold removing the investment material The entire system including the bead jar is pressurized to 35 psi If any leaks occur this reduces the velocity of the beads and hence lowers the cutting force The two primary locations where leaks can develop are in the two O Ring seals Beads can worm their way underneath the sealing surfaces creating a path for air to escape See O Ring Seal 1 in the Jar Lid and O Ring Seal 2 in the wand in the diagram above The procedure for cleaning the O Ring Seals is described in detail in the Maintenance section of this manual 13 Mold Not Cut to Center Premature Cycle Termination Press the Abort key to reinitialize
18. ng temperature then spending another How Does it Work The Xcavator uses a robotic grade precision stepper motor to digitally turn the investment mold in an ultra precise rate of rotation This rotation is computer controlled to spin slowly at the outside periphery of the mold and slowly accelerate as the swing arm approaches the center of the mold rotation This precision is the key to controlling the depth of cut and the uniformity of material removal across the horizontal material removal plane Controlling the Depth of Cut There are four factors which affect the depth of cut in a given mold 1 Air Pressure 2 Spindle Rotation Speed as set by the Depth of Cut Knob 3 Density of Investment Material AND Concentration of Special Liquid 4 Bead Media Size and Hardness As a rule of thumb the air pressure should be set to the lowest psi value that will yield satisfactory cuts throughout the range of investment brands and concentrations by adjusting ONLY the 16 position spindle speed selector knob Whip Mix has determined that 35 psig is the pressure setting which will cover the entire spectrum of currently available brands and concentrations The hardest and highest density investment should be run on a Depth of Cut setting towards the higher numbered positions while less dense investments should be run on the lower numbered settings 5 15 minutes to hand divest you can remove the mold from the press furnace press the
19. orted reliably An electric Bead Dryer Belt is supplied with the Xcavator When placed around the bead storage container it will raise the temperature of the beads and drive off any moisture the beads might accumulate Treat Pressurized Components With Care Never strike the bead jar or pull on the connecting air tubing while the system is pressurized This can result in cracking the plastic jar or wind up spraying glass beads or plastic debris around the area and pose a safety hazard Particulate Exposure Never open the cabinet door while a divestment cycle is in progress The exhaust system will pull the dust cloud towards the rear of the cabinet but air conditioning heating convection currents in the room could cause a portion of the dust cloud to escape into the room and pose a possible health risk Handling of Hot Investment Molds Always use laboratory tongs to handle hot investment molds and cautiously test the temperature of divested molds before you attempt to remove divested molds from the cabinet Exhaust Flow Volume The built in vacuum sensor will prohibit divesting unless the vacuum flow is sufficient to remove the airborne dust rapidly If you are having dust cloud removal issues check your vacuum unit or central vacuum flow to ensure removal of the fine dust Divesting Media Composition and Particle Sizes Use only 50 100 micron glass beads with the Xcavator for the following reasons 1 Other material types
20. revention of static electrical charge buildup If for any reason you receive a static electrical shock from any part of the equipment you should verify the integrity of the grounded outlet the unit is plugged into or call an electrician Operating the unit ungrounded can result in painful shocks to the operator and damage to the electronics of the unit itself Never cut the ground stud off the power cord or plug the unit into a 2 lead extension cord or outlet Dry Air Supply All compressed air condenses moisture in the air lines as a result of the physics of gas compression This moisture can accumulate in low areas of the air piping even if there is a master air dryer at the compressor It is recommended that a cartridge type dryer be placed just before the air regulator of the unit If moist air enters the unit it will collect in the reservoir and cause clumping of beads and disrupt the critical air bead ratio needed for consistent divestment It can also plug up either the reservoir output orifice or the bead air injector inside the injector block and cause inconsistent divestment Dry Bead Supply The strainer supplied with the Xcavator serves two purposes 1 it eliminates clumped beads and foreign debris which could clog the bead transport system 2 it validates invalidates the dryness of the beads If the beads will not pass through the strainer without tapping or shaking the strainer then they are too moist to be transp
21. s in operation The beads inside the jar should cave in on themselves every thirty seconds or so such that the funnel at the top surface of the beads has a gentle slope If the funnel resembles a vertical pipe extending more than one half inch or so down into the beads it is the elevated moisture content causing them to stick together like glue Another indication is the two inch plastic tubing on the bottom of the bead jar closest to the front of the Xcavator 12 should be full of beads You can tell this by placing your finger behind the tubing and if the tubing is full of beads you will not see the shadow of your finger behind the tubing If the tubing develops air bubbles or runs completely dry turns almost transparent and the Bead Jar has Beads this is the moisture gluing the beads together at the bottom so they won t pass into the tubing even with 35 psi pressing down from the top of the Bead stack When this happens the best remedy is to scoop out or vacuum out the beads and refill the jar with dry beads Moisture in the Supply Air Typical cutting issues result in investment molds which are not fully divested or are not divested at all An example might be a single hole at the initial starting point at the outside of the investment mold as shown in figure 1 If the beads are dry going in but demonstrate the tendency to accumulate moisture once inside the bead jar then the source of the moisture is the air s
22. the system then deliberately select a smaller ring size cycle usually 100 gram to finish the mold in progress The most likely cause is fluctuating or low volume flow of the vacuum sensor during the run Replacing the dust collector bag is the best way to increase the vacuum air flow Oblong Cutting Inside Mold The mold is not centered inside the chuck or the wrong too large chuck is installed or a non standard ring former was used Jet Begins Cutting Too Far Inside The Mold 1 Wrong Cycle selected TOO SMALL 2 Internal synchronization lost Press Abort key to re synchronize 3 Chuck assembly not seated over the two index pins on the mounting plate Xcavator Operating Instructions Troubleshooting continued Adjusting the Wand Height for Optimum Results The default wand height setting may not be optimized for your conditions to produce the desired uniformity of the cut If the Wand is too close to the top of the investment mold s top surface you may get concentric tree ring patterns with thin partitions between the grooves If this is undesirable you can loosen the thumbscrew holding the wand to the swing arm and raise the wand approximately 1 8 This will allow for a wider groove or track during cutting so that you don t have the thin partitions between tracks A word of caution though the farther away the Wand is from the top of the investment mold the less cutting force at a given knob setting
23. upply itself This can range from micro drops of moisture too fine to see with the eye to a visible vapor which rapidly accumulates inside the clear plastic catch bowl on the bottom of the air regulator The air regulator is located on the back of the Xcavator cabinet and has the pressure gauge on it If the air supply is far away from the Xcavator moisture may collect in low spots inside the delivery lines If moist air is a chronic problem cartridge dryers may be obtained from WW Grainger or a plumbing supply company and fitted just ahead of the air regulator to dry the air before it enters the Xcavator Depth of Cut First check the obvious causes 1 Check that the Knob selection is correct for the investment type and special liquid concentration 2 Check incoming air pressure is 35 psi on the Air Regulator gauge 3 Verify the bead level in the jar is slowly dropping 4 Clean replace nozzle tip If the depth of cut is uniform no skipping or holes as in the diagrams above but the depth of less than normal for your regular knob setting then the cause is a pressure loss in the air system The block diagram on page 13 shows the bead transfer system and how the incoming air powers and accelerates the beads to the needed velocity to do the work of removing the investment Xcavator Operating Instructions Troubleshooting continued HEAD FLLPN m mom EY AIR FLOW I I WAND l SWING ARM I O RING a
24. wl and pushing it upward This will open a check valve allowing the incoming air pressure to blow the bowl empty NOTE YOU WILL HEAR THE WHOOSHING NOISE OF THE AIR ESCAPING WHILE YOU HAVE THE BLACK PLASTIC RING RAISED Simply release the black plastic ring when the bowl is empty and a spring will snap it back into place closing the relief valve The whooshing noise should cease If it does not simply push up and release the ring until the noise disappears 10 Jar Lid Gasket Cleaning Over time bead fragments and dust can worm their way up into the retention groove of the Jar Lid and cause air to escape from the jar which is one of the two primary reasons for loss of cutting depth The other reason is the O Ring displayed in the pictorial on page 11 This simple procedure can be quickly performed to restore the proper cutting depth Use a DRY cloth or paper towel to clean the threads of the cap Unscrew the Jar Lid and use a dry cloth to clean the dust and or any beads adhering to the square Gasket in the lid as shown in the picture above If the gasket is not seated flat in the groove pry it loose and remove it Once removed clean all surfaces with the dry cloth and also clean the groove NEVER USE WATER OR ANY OTHER LIQUID TO CLEAN THE GASKET AS IT WILL PROMOTE BEAD CLUMPING REPLACE THE SQUARE GASKET IN THE GROOVE SCREW THE LID ONTO THE JAR UNTIL TIGHT THEN REMOVE IT AND INSPECT THE GASKET POSITIONING IF THE GASKET IS
25. zle requires replacement by noticing whether the depth of cut becomes significantly shallower than when the tip was new provided the air pressure setting and Depth of Cut settings have not been altered Turn the Xcavator power off Open the front door of the Xcavator and reach in and grasp the cutting hand piece and swing it into the center of the door opening Unscrew the Nozzle Cap on the lower end of the Wand by turning it clockwise When viewed from above the Wand the nozzle and the O Ring should separate from the Wand and you can withdraw these three items in your hand See pictorial at right 11 Description Item Note The O Ring goes inside the nozzle cap AFTER the nozzle Remove the O Ring then the old nozzle from the nozzle cap Place the new nozzle into the nozzle cap allowing the nozzle to drop into the hole in the cap Place the new O Ring provided on top of the new nozzle Re attach the three pieces to the end of the Wand by screwing the Nozzle Cap counter clockwise when viewed from above the Wand Xcavator Operating Instructions Troubleshooting Diagnosing Cutting Issues Typical cutting issues result in investment molds which are not fully divested or are not divested at all An example might be a single hole at the initial starting point at the outside of the investment mold as shown in figure 1 Another example might be a skipping circular groove as shown in figure 2 Figure 1 I
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