Lulzbot MOARstruder Documentation
Draft version undergoing active review by Aleph Objects
This page is about the Aleph Object MOARstruder, developed in conjunction with E3D. The following are a set of instructions specifically for the assembly of the hotend, and are complimentary to the ones already available on OHAI. Please note that these instructions use the "hot-tightening" technique so do not necessitate the use of any sealing compounds and should require less torque during assembly.
- Pliers and/or spanners (for holding the block and nozzle)
- Allen keys corresponding to the screws used
- A means of heating up your hotend and keeping it at a stable temperature (we recommend using a 3D printer)
- By hand, screw in the HeatBreak into the heater block in the end furthest away from the sensor cartridge hole. The break must be screwed in to the point where the top of the threaded section is exactly flush with the top of the heater block.
- By hand, screw the nozzle into the other end of the heater block. When you feel it mate with the HeatBreak, you should see a gap of around 1mm between the top of the hex section on the nozzle and the heater block.
- If the gap is too large or small then the heat-break may be in too deep or not deep enough respectively, re-do step 1.
- If the HeatBreak is in the correct place and the nozzle is still too close to the block, contact E3D for advice.
- Gripping the Heater Block with a spanner, very gently tighten the Nozzle with a second spanner.
NB - at this stage we are just doing the nozzle up to the point where it will not fall out, ready for hot-tightening later. Accordingly finger-tight is plenty (around 1Nm).
- Slide the sensor and heater cartridges into the block making sure that both pairs of leads exit from the side where the retainer plate is to be installed.
- Place the retention plate onto the side of the block where the wires come out and screw it into place with the supplied M3 socket cap screw. Make sure the sides of the plate are parallel to the sides of the block.
- Sliding the cartridges so that their housing is in contact with the plate, use the supplied M3 grubs screws to fix them in place.
It is important not to over-tighten the screw against the relatively soft copper-cased sensor cartridge, doing so can cause deformation of the cartridge making it hard to remove at a later date or even cracking of the potting ceramic resulting in poorer thermal response or in extreme circumstances, short circuit.
- Check that the wires for the heater cartridge are well clear of the retaining plate and are not oriented in such a way that short-circuit could occur.
- Place the HotEnd into a heat resistant surface and plug in the heater and thermistor wires into your assembly rig (or printer). DO NOT TOUCH ANY PART OF THE HOTEND WITH YOUR BARE HANDS FROM THIS STAGE ONWARDS (until the HotEnd has been turned off and the cooled to room temperature).
- Heat up your HotEnd to 285°C.
- Try to avoid overshooting this temperature as this can potentially damage the thermistor temperature sensor (300°C).
- Be also mindful of the tools getting hot and/or interfering with the temperature stability of your assembly rig (or printer). If the HotEnd is being held by pliers during the heating phase, the added thermal mass might cause the assembly rig (or printer) to suspect a “Thermal runaway”, and to raise the appropriate error.
- To prevent this, avoid touching the HotEnd with the tools before it has reached the required hot tightening temperature. Once gripped, the HotEnd will cool due to the contact with the colder tools, and this might also raise a “Thermal runaway” error.
- The process of tightening being very brief, this should not be too much of an issue.
- If the error is raised by the software, simply turn it off and on again.
- Please be careful as the HotEnd remains hot for a while after the heater has been turned off, avoid touching it with your bare hands.
- When the HotEnd is at temperature, tighten the nozzle with a spanner whilst holding the heater block with another spanner. This will tighten the nozzle against the HeatBreak and ensure that your HotEnd does not leak.
- You want to aim for 1.7Nm (15lb.in) of torque on the hot nozzle
- The nozzle does not need to be torqued down incredibly tightly to form a good seal as when the block cools down, the aluminium will contract and hold the Nozzle and HeatBreak together with incredible force.
- Tightening the nozzle too much might break the nozzle.
- Note: The above process should negate the need for high tightening torques and the use of any sealing compounds.
- Turn off your HotEnd heater, and let it cool.
- Once the HotEnd has cooled enough (~40°C), turn off your assembly rig (or printer), screw in the heatsink and heatsink fan and mount your hotend to your carriage.
- We recommend that you do not run your HotEnd at temperature without the heatsink fan being on. This reduces the chances of jamming happening in the HeatBreak.