Calibration issue or something else? (Page 2 of 2)

Got the gear pulley off by working a 1/16" SAE hex key into the 1.5mm hex set screw head.
So I salvaged the gear pulley but not the set screw.

I removed the whole 6mm shaft at the rear and of course discovered that the gear pulley set screws were turned down so tight they dug into the shaft itself.  This is unlike the extruder 'gear' which was unable to dig into the that stepper's output shaft.

What is interesting is that the drive gear pulley was apparently set into place 3 times.  It has 3 distinct landing area on the shaft.  It was interesting getting that drive gear pulley off as well as all those set screw landing spots made it hard to slide on the shaft.

If anyone needs the the MXL drive belt from the Y axis stepper is marked on my system.
It is an SDP-SI part number: SDP A6Z16 084 025/060
That should be actual part number: A6Z16M084060 (the M is implied, 84 is the number of teeth, the 025/060 are SAE/metric belt width).
This is just a fiberglass reinforced neoprene belt so a steel or Kevlar reinforced belt would be an improvement.
I'll set about ordering those today.

I will clean up this shaft and try to reuse it with my inbound FairLoc(TM) replacements.  Given this is a recommended and seemingly common enough adjustment the FairLoc(TM) should probably have been the first choice as they are the least likely to damage the shaft if properly tightened.  When I use them I will mark the shaft position with regards to the gear pulleys so I can visually detect any slippage.  I can infer from the lack of futher damage to this rear Y axis shaft that the previous owner did not actually achieve this calibration otherwise the shaft would have more landing areas from set screws or marks from the set screws slipping.  Probably stripped out the head and gave up on it.

I removed the shaft above the Y motor (the shaft the Y motor turns and through that moves the axis).  However now that you mention it that stepper will be removed and a flat will be put in that output shaft as well before I am done.  I already (in another topic) ground a flat in my extruder stepper with excellent results (at least for me).

FairLoc(TM) hubs are designed to reduce the exact issue you pointed out earlier in this topic.  They are essentially a compression hub made out of aluminum but unlike the set screw they grab most of the shaft circumference.  SDP-SI sells them (this idea is patented) as alternatives for gears, pulleys and other applications where non-marring adjustment of that item will happen often.  There are other ways to do this, and FairLoc(TM) does require some regularity in the shaft dimensions, but in this case I can substitute these gear pulleys for the ones on the shaft without cutting a flat at all.  Effectively it is a drop in replacement.  As those 2 gear pulleys were obviously heavily tightened because without a flat they would otherwise slip.  My hope is with the FairLoc(TM) hubs I won't have that sort of issue.  Course as proprietary parts they cost a bunch more.

I bought 3 18 tooth FairLoc(TM) hub pulleys at basically $19 each.
I won't need one for the stepper because I will put a flat in that shaft, there is no rotational misalignment there that requires adjustment...just the need to stop it from slipping so the $5 existing stepper gear pulley is just fine.

Has anyone tried replacing the MXL belts with GT2 belts?

In theory that should reduce the backlash.