Taz 6 retract before z home?

I’m sure this has been covered before but I had no luck searching (terms are too general).

Current behavior for my Taz 6 (moar struder or stock extruder is the same):

  1. Select “print from SD” through the GLCD. Taz gets up to temp. Generally there is a small (5-10mm) of filament dangling from the nozzle leftover from the prior print.

  2. Taz homes Z on the disc switch with this filament dangling.

  3. Taz does a retraction (not sure how much material…could check the gcode I imagine).

  4. Taz runs through its wiping procedure on the brilo pad.

  5. Taz homes all four bed corners, homes to start position, then prints.

Why aren’t procedures 2 and 3 switched, retracting filament before homing on the disc switch? Does it matter in the end? Is the disc switch physical or electrical, ie, does the nozzle find home by closing a circuit between the nozzle and the switch like the four corners, or is it more like the older style Z home from the taz 1-5 where the nozzle physically closes a switch.

I have been trimming the filament from the nozzle when the machine is powered down, but have been (perhaps unnecessarily) paranoid about shorting the sensing circuit with say, static discharge.


I wipe my head right after each print … check out my handy wipe tool I made for just that purpose the stl is on the hardware page for taz 6 under wipe tool

To save everyone from searching… https://forum.lulzbot.com/t/wiper-hand-tool-free-stl-file/6564/1