Printer Bed Adhesion

[grezmel]

greznel if you're scraping glue off the bed with the nozzle end - adjust your calibration. The nozzle shouldn't actually touch the print bed.

Are you calibrating before or after you apply the glue stick ?
Given the really tight tolearances 3d printers work with you should calibrate AFTER applying glue. As the layer of glue will be thick enough to effect the print.

I only really put a thin layer down and have bed levelled before and after on many occasions - ive even purchase a dial guage to assist.

Im using a Bulldog extruder XL, hex hot end and 0.4mm nozzle and 1800mm/min - when I clean the nozzle it prints perfectly for a few prints, then for no apparent reason it will stop extruding correctly and clicking halfway through a print - it seems to start on infills and then a few layers up on perimeters. It happens whether I print the PLA at 190 - 200, or slightly higher at 205 - 215. When in a good mood it will print at 190 no problems.

Im wondering whether the filament is swelling in the small tube between the hex hot end fin area and the heating block and getting stuck with slight retracts during the print (retracts of 0.5mm, so nothing major). Ive got a 40 mm fan blowing through the fins and it happens with or without the fan running.

Ive also got a 60mm fan blowing directly on the to stepper drivers to keep them cool - My Stepper drivers are A4988's and I was tempted to upgrade them to some DRV8825's.

When it works Im very happy with the resulting print, but when it plays up - meh !