These are the instructions for assembling batches 2, 3 and later hot-ends. If you have a batch 1 hot-end, please see the batch 1 instructions. All of the MakerGear Prusa Mendel kits are batch 3 or later. Most PLA and ABS operates under 220C. If you need to increase the temperature above 220C there may be a problem unrelated to the the hot-end such as filament tension, thermistor table, etc.

Note: On batch 2 hot-ends, one end of the heater barrel is marked in red. The red end goes into the V3 Hybrid, it does not go into the nozzle. This does not apply to batch 3 or later, in batch 3 or later you can use either end.

Batch 2 is shown here (V3 may also be black)

Batch 3 is shown here (V3 may be tan). M6 jam nuts are included but are not shown in the photo.

Hand tighten the heater barrel into the nozzle. Be sure the red end (batch 2 only) is not going into the nozzle. Tighten the two included M6 nuts together on the heater barrel (jam nuts).

Place socket on the nozzle (you can also use pliers or a wrench if you don't have a socket). Use pliers or a wrench to tighten the outside jam nut (as shown) - turn the barrel 1/4 turn into the nozzle. Turning it too far can damage the nozzle and not tightening it enough can result in leaks. Properly tightened, as explained here, you will not have any leakage between the barrel and nozzle.

 

Thread the HeatCore onto the barrel with the wires pointing away from the nozzle. Turn it until it is tight against the nozzle. If there is anything blocking a contact (excess ceramic, for example), sand or scrape it off. The HeatCore should be tight against the nozzle.

Optional Step: Wrap barrel with ptfe tape before attaching V3 Hybrid. The wrap shown here is 2.5 inches of 1/2" x 0.002"  PTFE tape - this is commonly sold at hardware stores. Make sure that no wrap is in the barrel opening.

Thread the V3 Hybrid onto the heater barrel and hand tighten it. The V3 Hybrid should be very tight but it does not need to be cranked on. I typically hold the nozzle in a socket wrench when hand tightening the V3. If everything is mounted correctly there should be a slight gap (~1mm) between the HeatCore and the V3

Batch 2 hot-end shown here

Batch 3 hot-end with PTFE wrap shown here. You may want to remove the excess ptfe tape with tweezers or a small screw driver. The gap between the HeatCore and V3 is a slightly smaller on batch 3. Note: kits are now shipping with nozzles that have a steeper tip. With the steeper nozzles, the gap between the HeatCore and V3 (PEEK) should be under 3mm.

Secure the thermistor to the nozzle with kapton tape. It is very important that the thermistor is firmly attached. Use 4 or 5 wraps. If the thermistor comes loose, the hot-end can get too hot and start leaking or jamming.

Place the smaller piece of insulation over the nozzle as shown.

Place the large piece of insulation over the smaller insulation, as shown.

Your hot-end is ready!! Do not run your hot end over 240C unless you know what you are doing!