Budaschnozzle 2.0 PLA fix - PTFE on Heater Block

If you plan to change nozzles frequently this fix is the best option of the three. However, this fix does require removing more parts than the other two.
Required Tools
  • PTFE tape, also known as plumbers tape
  • 13mm wrench
  • 18mm wrench or pliers
  • 1.5mm hex key or driver
Warnings

If you have experienced PLA leaks you will need to perform this procedure after the hot end has reached 160C. Unless heated past 160C, any PLA on the threads will influence how easily the items can be moved. Removing the nozzle with the hot end cold, with the presence of PLA on the threads can potentially damage the threads.

When re-installing the nozzle, slightly thread the nozzle onto the threaded extension, only one thread then set the hot end temperature to 160C. Once the hot end has reached 160C finish installing the nozzle.

Take extreme caution when handling the hot end when at high temperatures; when at 160C the hot end can cause severe burns. Use a pair of pliers or thick leather gloves when handling the hot end when at extrusion/melt temperatures.

If your hot end has not been used this fix can be done with the hot end at room temperature. Any instructions below stating to heat the hot end, can be ignored when starting with a fresh Budaschnozzle 2.0.

Procedure

For TAZ users, to remove the hot end refer to the instructions found here: TAZ: Removing the X Carriage Extruder Plate, Extruder and Hot End

Temporarily connect the hot end to the hot end connector on the extruder wiring harness. Connect the printer to the host computer, plug in the 3D printer and turn on.

In Pronterface set the hot end temperature to 160C and allow to come to temperature. Once you have your tools ready and the hot end has reached 160C turn off to power to the hot end. The hot end will begin to start cooling; if the hot end is allowed to cool too much, reconnect and heat it back up to 160C before trying to remove the nozzle.

Use the 18mm wrench, or pliers, to hold the heater block in place away from the heater resistor wire and the thermistor wires. Use the 13mm wrench to turn the nozzle counter clockwise to loosen and remove the nozzle.

Set the nozzle aside. Using the 1.5mm hex key or driver loosen the set screw located on the side of the heater block. The screw does not need to be removed, only loosened enough to allow the heater block to turn off of the threaded extension

Locate the orange and red wires and remove them from the upper wire stress relief slot. You may need to untwist and pull two wires at a time from the slots.

Once the wires are removed from the slot rotate them downwards so the wires run parallel with the length of the heater block, as shown in the picture below. Take extra care not to bend the wires near the heat resistor or thermistor; with multiple bends in the resistor leads the leads can fail and break.

Again temporarily connect the hot end to the hot end connector on the extruder wiring harness and heat the hot end to 160C. Once the hot end is up to temp turn off the power to the hot end and use the 18mm wrench or pliers to turn the heater block, counterclockwise, off of the threaded extension. If you feel any tension when turning the heater block off, try turning it clockwise a turn or two to realign the threads and then try turning counterclockwise again.

To clean the threaded extension threads, while the hot end is still hot and the printer turned off wipe the threads clean of any residual PLA. If the PLA has cooled and is unable to be wiped, turn off the printer, reconnect the hot end and bring the hot end back up to 160C. While the threaded extension is still hot and with hot end and the printer turned off use a paper towel to clean off any melted PLA still left on the threaded extension. If the PLA has already cooled, a dental pick can be used to chip off the PLA. Once the nozzle is removed you can clean the PLA from the nozzle by wiping while hot or soaking the nozzle in a hot water bath and brushing the PLA away.

Now you will need to wrap PTFE around the threaded extension where the heater block sits when installed. Align the bottom of PTFE tape 6mm up from the bottom of the threaded extension. Make 3-4 tight wraps around the threaded extension and then cut the tape to remove the roll of PTFE tape.

Smooth down the cut or torn end onto the threaded extension.

Slowly turn the heater block back on to the threaded extension. If you feel any tension, you will need to again heat up the hot end to melt the PLA and get the heater block threaded back into place.

Slowly turn the heater block onto the threaded extension, over the PTFE tape, until the bottom of the heater block is more that 6mm up from the bottom of the threaded extension. If the hot end is hot it is easiest to hold the heater block with pliers and hold the Budaschnozzle aluminum mount plate to turn the hot end into the heater block

With the hot end still heated, turn the nozzle onto the first thread of the threaded extension. Allow the nozzle to heat up to soften the PLA in the nozzle threads. Once it has heated, use the 13mm wrench to turn the nozzle clockwise onto the threaded extension. Turn the nozzle until it snugs all the way on to the threaded extension, but do not over tighten it.

At this point there may be a small gap between the nozzle and the heater block. Turn the heater block counterclockwise until the bottom of the heater block touches the top of the nozzle.

Using the pliers or 18mm wrench on the heater block and 13mm wrench tighten the nozzle against the heater. Also, make sure not to over tighten the nozzle as this can ruin the threads.

Gently and carefully guide the 2 wire pairs into the wire strain relief cutouts on both wooden plates. The hot end can be rotated gently as needed to ensure proper alignment. Follow the pattern shown for both the orange and red wire- Up, over & down, over & back up through the last strain relief cutout. Make sure to check that the clear PTFE insulation is still covering the wire crimps and resistor leads before powering up the printer. If the leads are exposed the hot end can potentially short against the body of the hot end.

If you have any further questions or would like assistance please contact us at Support@LulzBot.com. Please include your order number, name, order date and as much information as possible.