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Product Support Miniature Plastic Molding is committed to providing person-to-person support on all of our products. Machine Documentation and Downloads Detailed Troubleshooting Documentation (with illustrations) Contact us for additional information Company History Click here for information about Miniature Plastic Molding. Frequently Asked Questions Troubleshooting General Electrical Troubleshooting Suspected pyrometer or thermocouple failure. Suspected heater band problems. Frequently replacing heater bands. Breaker continually trips. Screw returns and doesn't stop extruding. All "Wasp" Models (#45, #50, #55) Mold suddenly will not stop flashing. Material flashes where nozzle contacts sprue opening. "Wasp" Models #45 and #50 Plunger goes in short distance and then stops. Mold will not eject from V slot. Plunger drifts down after cycle (Model #45 only). "Wasp" Model #55 Mold will not eject from the V slot, but was ejecting normally last week. On semi-auto cycle, the inject timer does not start. The cycle timer runs until it times out. Screw turns, but does not return to make extrude limit switch, or does so very slowly. I put material in, but it won't inject when there is no mold in the machine. At the end of the cycle the carriage lifts up, but the machine stays under load until the breaker trips. Material (polyester resin) will not feed. No hydraulic pressure when machine is running (3-phase machine). Models #70 and #75 with Exor uniOp operator interface Machine will not save job recipes. Distance values have changed. Machine alarm information for Models #70 and #75 with Exor uniOp operator interface Empty Filter Temp - Cut Bk. Temp - High Temp - Low Extrude Back Shuttle Safety (or Gate) Clamp Inject Car-Bk Mold Interchangeability "Wasp" V-Mold Machines Model 60 Model 70 Model 75 Miscellaneous Do you have electrical drawings available for download? Troubleshooting General Electrical Troubleshooting Back to Top   Suspected pyrometer or thermocouple failure. Swap leads with another zone and see if it changes. Suspected heater band problems. Unplug twistlock plug from control box and measure resistance across the plug tines. Most heater failures are from lack of continuity. If heater checks OK, unplug twistlock and measure voltage at the socket. If the LED on the pyrometer is on (indicating that it is calling for heat) and no voltage appears, replace the load relay. Or, the dry contact in pyrometer may be burned out. Frequently replacing heater bands. Always re-tighten bands after first heat cycle. They will loosen quite a bit, and the air gaps will shorten heater life. Breaker continually trips. Replace with 20 Amp breaker. Screw returns and doesn't stop extruding. The extrude limit switch is not being tripped. You may have to loosen the bolts holding the tripper bracket and twist the bracket to align the tripper with the limit switch. All "Wasp" Models (#45, #50, #55) Back to Top   Mold suddenly will not stop flashing. Check if nuts on clamp tie bars are loose, and tighten if necessary. Material flashes where nozzle contacts sprue opening. Make sure mold stop is correctly set to align nozzle and sprue. Sprue opening must be at least 5/32" diameter. (Nozzle orifice is 1/8"). "Wasp" Models #45 and #50 Back to Top   Plunger goes in short distance and then stops. Material (usually hard resin like polystyrene) is packed into upper non-heated area of the heating cylinder. Remove heating cylinder and turn upside down on bench to loosen pellets. Put back in the machine and inject without adding more pellets. If this doesn't work, you must heat the cylinder in an oven to melt the material. Mold will not eject from V slot. Adjust the stop nuts on the mold ejector rods to give the ejection more stroke. The nuts should be set so that when the plunger is all the way retracted (hitting the plunger return limit switch), the mold can just slide freely in and out of the V slot on the mold ejector bar. Plunger drifts down after cycle (Model #45 only). Replace check valve in exhaust port of directional valve (older models with Numatics directional valve). "Wasp" Model #55 Back to Top   Mold will not eject from the V slot, but was ejecting normally last week. Check whether the carriage cylinder threaded end has turned out of the carriage push plate. If you can see any clearance between the shoulder on the piston rod and the small black spacer between the shoulder and the push plate, the rod has un-threaded. Re-tighten the rod using blue Loctite. On semi-auto cycle, the inject timer does not start. The cycle timer runs until it times out. The inject timer is started by the pressure switch under the carriage directional valve and check valve. It is set at 1750 PSI. If the main relief valve on the manifold (later machines) or the main relief valve on the pump housing is set lower than that pressure, the switch will not activate. Main relief valve on the manifold should be set at 2000 PSI. Valve on pump housing should be set at 2050 PSI. Once the pressure switch contacts are closed, 1CR inject relay is energized and latches, starting the inject timer. If pressure adjustment doesn't help, replace 1CR. Screw turns, but does not return to make extrude limit switch, or does so very slowly. Material has melted at the point where the hopper tube joins the barrel. It will melt a small, quarter-sized plug that blocks the screw feed port. Hopper tube must be removed. Do not let machine sit idly with heaters on. Do run water to the hopper tube ports. I put material in, but it won't inject when there is no mold in the machine. The non-drool nozzle requires contact against the mold or purging fixture to operate. This applies to all machines with the non-drool nozzle. At the end of the cycle the carriage lifts up, but the machine stays under load until the breaker trips. The carriage return limit switch is not being tripped. Adjust the small tripper rod to trip 1/8" short of full carriage up stroke. This can also be caused by problem (1) if the rod un-threads. Material (polyester resin) will not feed. Material may have kicked over and solidified in the transition zone of the screw. Screw must be removed and cleaned. No hydraulic pressure when machine is running (3-phase machine). Motor running backwards. Switch 2 of the 3-phase hot leads at the motor starter. Models #70 and #75 with Exor uniOp operator interface Back to Top   Machine will not save job recipes. If "flt" LED in upper corner of screen is lit, the battery in the uniOp must be replaced. Distance values have changed. If F3 Limits screen is paged up and the operator accidentally hits the F7 Function Key, the 2 axes will be re-zeroed. To properly restore zero, inject to bottom out the screw, and close the clamp all the way without any mold in place. With the F3 screen in use, hit F7 and machine will be re-zeroed. Machine Alarms for Models #70 and #75 with Exor uniOp operator interface Back to Top   Empty This indicates that the screw did not return during a semi-automatic cycle due to the material hopper being empty. Filter This indicates that the return line oil filter is dirty, and by-passing. The machine will run under this alarm condition, but must have the filter replaced. Temp - Cut Bk. Automatic temperature cut-back has occurred. Temp - High Indicates that one or more heat zones is 15 degrees above setpoint. The machine will run under this alarm condition. Temp - Low Indicates that one or more zones is 15 degrees below setpoint. The inject, retract, or extrude functions are disabled under this alarm condition. If you wish to dry cycle the machine with an empty barrel, adjust the set temperatures on F1 screen to match ambient temperatures shown on "actual." Extrude Back Screw did not return to position-empty barrel. Shuttle Ejector did not return within 5 seconds of eject timer timing out. Safety (or Gate) Gate is not closed, making proximity switches. Or, when machine has an automatic-opening gate, the switch on the mechanical interlock has not been made and released. When the machine clamp stroke is shortened, the safety pawl will not fall into the relief in the safety bar without the safety bar being adjusted out. The machine must see this switch opened and closed to allow the next cycle. Clamp Clamp position potentiometer has failed (seeing a zero reading). Inject Injection potentiometer has failed (seeing a zero reading). Car-Bk (carriage back) Sprue break is turned on and carriage is not in the raised position at the start of a cycle, tripping the carriage back limit switch. Mold Interchangeability "Wasp" V-Mold Machines Back to Top   Molds used in the previous generation of Mini-Jectors built from 1946 to 1987 (including the Model 40, Model 40A, and old style Model(s) #45 and #50) came in two sizes: 4.5" long x 2.625" high 6.0" long x 2.625" high (current Mini-Jector part number 121230) These molds can be used without any modification in any of the current "Wasp" Model(s) #45, #50 and #55. If the current machine has the wide mold option, the smaller mold would require the use of the factory-supplied adapter. Model 60 Back to Top   The Model #60 is a horizontal clamp, vertical injection machine which injects at the mold parting line. The distance between the stationary platen and the parting line is adjustable. Molds from the following older Mini-Jector "Hornet" models will fit the current Model #60 with no modifications: 60HC75 60HC80 60AM80 "Mini-Matic" 60PC75 60PC100 65HA100 "Auto Hornet" HV1-18T (same as 65HA100) HV1-25M HV1-25T HV1-25RS HV1-30RS, ARS The models listed above all used the Newbury 5" x 6" x 5.125" thick mold bases, or the DME 5 x 6N and 5 x 8N mold bases. All except the 30 ton models have a fixed parting line distance of 2.375". Although the last four models listed had higher clamp ratings than the Model #60 (25 or 30 tons compared to the Model 60's 10 tons), the Model #60 has two-pressure injection, which permits better control over mold flashing. Other makes that will fit the current Model #60: Arburg C4B (using Arburg mold adapter part no. 620490) Arburg 150 (must be in parting line mold configuration) Boy 15 (must be in parting line mold configuration) The maximum parting line adjustment is 3.625" from the stationary platen. The mold shut height should also be checked. The Model #60 is available with either a 10.75" maximum shut height or an optional 12.75". Model 70 Back to Top   The Model #70 is the only Mini-Jector machine that does not use "parting line" injection; it uses the more common center sprue injection at the center of the mold. The machine can use the following commercial mold sets: DME 5 x 6U (does not require adapter) DME 5 x 8U (does not require adapter) DME 10 x 8N DME 8 x 8N DME 8 x 8 molds for Arburg and Boy machines National Mold base models for Arburg, Boy, Newbury and Van Dorn machines in the 8 x 8 size range Some of these bases come with a locating ring of 4" or 4.33" in diameter. The locating ring must be removed, as the mold will locate and center on the 2" diameter sprue bushing. The optional shuttle table limits mold width to 9". If the optional shuttle is not used, molds up to 17.75" wide by 9" deep can be used. Model 75 Back to Top   The Model #75 machine is a vertical clamp, horizontal injection machine with a fixed height of 3.5" from the lower (stationary) platen to the nozzle centerline. It has a shuttle table which serves as the stationary platen. DME produces a mold base called the 6" x 8" shuttle base that was used on the following machines: Newbury V1-30M Newbury V1-30T Newbury V1-30RS Newbury V3-30RS Newbury V4-30ARS Newbury V5-76RS Autojectors 35 ton Trueblood 35 and 75 ton Moslo Duplimatic Reed Duplimatic The 722281 adapter allows the use of the Newbury molds with a 2.375" parting line. This allows molds from the following Newbury and Mini-Jector machines to be used in the model #75: 70VC95 V1-18M 70VC105A V1-18T 70VC110 V1-18A If you have any doubts about mold interchangeability, please call the factory.   Miscellaneous Do you have electrical drawings available for download? Back to Top   Electrical drawings are available for models 45, 50, and 55 (standard household wiring). These drawings are in a .dxf format. Click here to access the download page. If you require drawings not available on our site, please contact us.

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