mk3s upgrade ptfe tube inside diameter too narrow?
ptfe tube in the mk3s upgrade appears to be too tight.
I just finished doing the upgrade to the MK3s print head and after i assembled it i was unable to feed in the filament.
After disassembly of the hotend, I tried to just insert the 1.75 mm filliment into the ptfe tube and it did not freely slide in, i checked the spare tube and also the 1.75mm fillament did not slide into that either.
I found the original ptfe tube that came with the printer before the upgrade and found that the inside the filament slides easily through it.
it appears that the ptfe tube's inside diameter for the kit i received is too narrow to be used. Is this expected, or did I do something wrong here...
RE: mk3s upgrade ptfe tube inside diameter too narrow?
Like anything else, PTFE tubes have tolerances. Yours seem to be on the too tight side.
If you contact Support through Chat, I expect they will send you replacements.
1.75 mm filament (which I hope you measured) should definitely not bind in the tube. That is a jam waiting to happen.
RE: mk3s upgrade ptfe tube inside diameter too narrow?
the measured filament is exactly 1.75mm.
So maybe this was a bad batch of ptfe tube...
I'll check with support chat when i have 20 minutes to wait for a reply....
RE: mk3s upgrade ptfe tube inside diameter too narrow?
Same criteria holds for any bulk PTFE you buy on the Internet. It is cheap, for a lifetime supply.
Cut some to length and make sure it is a good fit for your filament. The hole has to be centered also. And avoid oversize filament...
Bulk PTFE is cheap, and there are lots of cutting jigs on Prusa and Thingiverse. Cutting your own is not a bad alternative.
RE: mk3s upgrade ptfe tube inside diameter too narrow?
I observed the same thing when I upgraded from MK3 to MK3S. The newer tubes are in fact substantially narrower, to the extent by my measurements it would not even fit my filaments through.
However I went ahead and assembled it in anyway, and have had a total of maybe 4 jams over 6+ months of printing. None over the last ~2 months once my wife told me to bump up the temperature to unload.
ken