Partial blockage in teflon

[j3d 0]

I was having terrible under extrusion all week. I cleaned out the nozzle twice, performed the atomic method many times, and still nothing. The shape of the slug from the atomic method made me curious. It was narrow about an inch from the end, but still had a nice taper at the tip. Seemed like it was stretching a bit before finally coming out. Finally I removed the teflon spacer and found there was a hardened white ABS ring at the bottom. I passed a 1/8 inch drill bit through by hand to clear it out and now all is running well.

There has got to be a better way to change material. I can't imaging having to dis assemble the nozzle assembly every time I change from ABS to PLA.

 

[gadgetfreak 7]

Exactly where was the hardened ABS ring? At the bottom of the PTFE (inside) or below it (at the metal hot end isolator, the part with holes around it?)

Also, did you do the atomic with ABS or PLA and at what temperature?

[kris 29]

There has got to be a better way to change material. I can't imaging having to dis assemble the nozzle assembly every time I change from ABS to PLA.

 

Had exactly the same issues. I only print ABS now, I never mix materials any more. Will maybe buy a second UM2 for PLA.

 

[j3d 0]

Exactly where was the hardened ABS ring? At the bottom of the PTFE (inside) or below it (at the metal hot end isolator, the part with holes around it?)

Also, did you do the atomic with ABS or PLA and at what temperature?

 

The ring was inside the PTFE part. After I separated the metal isolator and PTFE part, I fed a piece of filament through the teflon part and it would not pass through the bottom. It was well hidden since the only ABS I have run is white.

I did the atomic method with ABS at 110 and later PLA at 90. I suspect the ABS tries helped, because the first few had a real thin, long point, where it probably didn't get too far into the hot area.