MK6 PTFE problem

Summary:

3mm abs binding in PTFE tube.

MK6 PTFE problem

sockles 09 Nov 2012 00:50

I've got the MK6 and I have replaced the red PTFE after too much use on the machine with new red PTFE and it seems that the red tubing, where the aluminum heater block is, is causing the red tubing to enlarge the inner diameter.

After the heater is at 220*C, maybe 2 minutes, I try to pull the filament out and push it back in a few times, which it should allow me to. But I can clearly see the filament has expanded. I have tried over and over to replace it with the same material to no avail.

Has anyone had this problem? I can take a photo if my explanation is difficult to read.

Re: MK6 PTFE problem

Jetguy 09 Nov 2012 15:47

It ALWAYS does that, the stock PTFE is obviously larger than the filament diameter to allow that to slide through in the first place. Nothing new here, your hot end should be hot when trying to remove filament. The second factor at play is your filament diameter which is not consistent between rolls and obviuously not garanteed to be even close to 3mm diameter usually being undersized.

Point being, it's either your expecation is off, or your particular filament is not the right size allowing more expansion than normal. The point is, if it went in, it will come out. It obviously is more difficult if the filament is undersized, then the difference to where the filament swells to match the bore VS the already too small diameter is more obvious at the print wheel, but if you keep the hot end hot, then the swelled part is soft and pulls back through fine. Again, this is all perfectly normal.

Last edited on 09 Nov 2012 15:50 by Jetguy Show more