Hi Folks,

bit lost for places to start diagnosing this one...

ZoneStar (2015 model) printer - set up as per rather amusing instructions and using provided firmware. A few teething issues but OK. (TBH I looked at the custom firmware configurator - no idea where to start eliminating options)

Set it to run a rather large print - 5-7 days at 0.1mm layer height.

3/4 of the way through the extruder stopped extruding. the head kept moving in the XYZ, but there was nothing coming out. The temperature display said def/ 0 oC def/ 0 oC. OK, something screwy with both temperature modules? maybe? Luckily I have a spare extruder.

fit spare extruder, do a few test runs - all OK.

do a longer test run - same problem.

I'm open to suggestions for what to look at next...

things I've noticed.

The extruder makes a clicking noise, and you can see it slipping.

I disassembled the clamp to check the cogs - now have no idea how tight to make the spring or how to adjust the spring.

well ain't that typical....

I searched for a reasonable amount of time for a solution before posting this..

very next hit I looked at was this one, which almost perfectly describes most of my problem... enough that I can start troubleshooting at least...

[www.rc-cam.com]

(and references this one too [www.geeetech.com] )

I'll see how I go and post an update.