Ultimaker PEEK Replacement
Description
This part will solve bowden tube popping issues. If you've got access to a manual (or CNC) lathe or a CNC mill, you can make it. I show it with a hex, but that is optional and I only did it as I had a CNC mill handy and in that case it didn't matter if it was round or hex. Round works just as well though! It was designed with help from Joergen Geerds and he and I have tested them over several months with PLA and ABS with great success.
Drawings and everything are included in the Zip. the STL is useless but thingiverse makes a nice preview out of it.
Drawings and everything are included in the Zip. the STL is useless but thingiverse makes a nice preview out of it.
Instructions
Machine out of PEEK. Teflon/PTFE may work but eventually will fail. You will also have to use an M7 die to thread your bowden tube about 12mm up. Note that I tried a cheap Harbor Freight die at first and it was no good.
I originally made mine from 3/4" diameter PEEK, but realized that 5/8" diameter PEEK should be fine, and is cheaper, so I redesigned it for that.
Its important that the M7 threads are AT LEAST 10.2mm deep. I show the hole as 11.2mm deep, but its safe to go deeper. The M6 threads that hold the nozzle on are plenty strong. I messed up the one on my machine so I've only got a few mm of M6 thread there, and its holding up just fine.
I originally made mine from 3/4" diameter PEEK, but realized that 5/8" diameter PEEK should be fine, and is cheaper, so I redesigned it for that.
Its important that the M7 threads are AT LEAST 10.2mm deep. I show the hole as 11.2mm deep, but its safe to go deeper. The M6 threads that hold the nozzle on are plenty strong. I messed up the one on my machine so I've only got a few mm of M6 thread there, and its holding up just fine.
License
Ultimaker PEEK Replacement by tlalexander is licensed under the Attribution - Creative Commons license.

Awesome! Just what the Dr. ordered. I like this better than having to cut the brass down and threading the bowen in the same hole.
Could you share your PEEK source? I have 5/8" PTFE here, but if I am going to do it, I prefer to do it right!
Thanks for reminding me about this, I knew someone had recently asked me something but I forgot where it was!
Anyway, you can get PEEK from McMaster Carr, or I got mine for about 1/2 the price from a local plastic supplier.