Hi All
@naPS OK on the pulleys - I guess that your Y pulley shaft must have been threaded rod or something then ?
@Gav - had already checked grub screws and all clamping were tight (as a duck's ar$e
) but rechecked again anyway. thanks.
OK, I completely replaced my alloy 12mm Y shafts with 10mm steel - turned to 6mm at the ends to suit the pulleys (all my pulleys are aluminium and are all the same). I replaced the single mount plates with dual mount plates and dual bearings. I realigned everything this morning - the belts are as tight as I can get them - not as tight as top E on my guitar, but close to bottom E/A ! (bear in mind I didn't have this problem before).
Sadly, the problem is
EXACTLY the same
I pulled out my old dial gauge and set it up on the stage and locked in position. Set the stage to go off in Y at 100mm and back again - did this tens of times and it returns to within 10 microns each time (0.010mm). I did this with the stage going positive and negative, measuring it from the back and front reference bars. This is definitely not backlash, or it would show on the gauge. I repeated the snake test using the dial gauge this time - in both directions (I reversed the system Y direction just in case) - again, it returned within 10 microns of it's start position.
Looking at the pulleys, I checked the runout on the shafts, pulleys and even did it with the belt surfaces - all within about 10-15 microns.
I even checked everything again using a vernier gauge just in case
I've attached a pic of the actual snake test - you can see both start and finish are accurately aligned, but the individual segments are not. Again, the total length should be 60mm, but they are exactly 59.0mm - the X is exactly 60.0mm and uses the same pulleys. I even gauged the OD of the pulleys just in case - as expected, all the same.
- Snake Test
So, for me, it is still pointing toward software/firmware contrary to Bill's results.
@Bill/@artofmystate, are you all using the latest and greatest versions of firmware and software ?
For reference, here's my setup again ...
Main board 7.12.04.01
LCD 5.12.02.29
LaserCAD 5.93
It would be interesting to see if artofmystate gets the same results from the backlash snake file.
I'm not sure I have any mileage left from a hardware standpoint - any smart ideas gratefully accepted - I'm stumped.
Cheers
Neil
PS, Just remembered, I swapped the stepper drivers too - exactly the same results