I’ve had the exact same problem with a brand new TAZ 6 I bought last month (December 2016). It seems to have always been off by a few millimeters, which wasn’t a big deal, but it was obviously misaligned, since you could see:
- The Z-axis homing comes down on the switch noticeably off-center.
- About 5 mm of the cleaning pad never gets touched.
- When auto-bed leveling, it hits the front and back washers in noticeably different spots.
This hasn’t really impacted printing or bed leveling, so I mostly have ignored it so far.
However, it actually has gotten gradually worse over the course of moderate daily use for about a month. It has now moved a least a millimeter or two and has just started to nick the cleaning strip housing with the nozzle when cleaning in the last week or so. It makes me wonder if something wasn’t QUITE torqued down enough and it has been slowly moving due to print vibration, etc.
Anyway, I was originally hoping there was a firmware calibration setting for this (Y-home offset or something), but it sounds like I should go ahead and do the adjustment with the physical hardware as described in this thread.
Is there an official procedure for this adjustment? I read the OHAI page on Y-axis assembly, but it didn’t seem to say how it gets calibrated in the first place. Baring other info, I’ll do something ad-hoc (but hopefully decent!) with a square & digital calipers. =)
Is there a torque spec for re-tightening the bolts? The OHAI page has torque specs for other bolts (the ones holding the Y rods), but for these bolts just says to “snug these down”. I’ve got torque wrenches, so I can easily torque to spec if there is a spec!