Clean out wasn't the raging success I was hoping for.  Got the barrel and nozzle out of the holder ok, then went to separate the nozzle and barrel (using the two nuts, grip tight method).  Only for the barrel to shear off just below the lock nuts.  So moved down the barrel a bit more, and have it shear off again.  Time for new barrel and nozzle, methinks.

Not been a great couple of days for printing, it must be said.

Some progress, in that I uninstalled and re-installed Repetier host, and now the commands charge off as normal.  Now the head is at least partially blocked (I suspect) - not a lot coming out the bottom, drive gear stripping filament and then it goes into terminal "spaghetti above the hot end" mode.  Give it a clean out today, see how I get on.

Have been trying to get the filament feed and multiplier sorted, and realised that the 1kg spool was most of my issue.  So I stripped a couple of metres off and tried again.  First print was much improved, all systems getting pretty close.  Did a re-measure of the filament, adjusted the filament multiplier setting and went to try again.

Now, the commands from the (dedicated) control PC are being sent at the rate of one every three seconds or so (according to the log).  End up with lots of little ABS dots, rather than a continuous print. 

Reconnected printer to a different USB port, ran again, same.  Turned everything off and reconnected, same. Turned on brim (which had been off) and the profile wouldn't save (kept re-zeroing the brim value).  Turned off and back on, and now the brim value is setting ok. 

But the command delays are still there.  First length of brim prints and sticks ok, then a series of dots at three second intervals to make the turn.  Then a dash to the next turn.

Killing the print job, all of the motors operate at normal speed and bed drops ok.  Scrape off debris, start again, same.

Reseated USB at PC and printer end, still same.

Thoughts?????