6 replies to this topic

[marco masento]

Hi, I was calibrating my Dec axis to correct backlash when it started to move freely even with the clutch on. I have a suspicion that I might have tightened too much the top screw and maybe stripped the thread. What could be the cause for this and how can I fix it?

[bignerdguy]

Try this:  Take the screw for the DEC lock nut off and remove the handle.  then turn the DEC lock screw down further. there is a small brass disc inside the channel where the lock nut is at.  if that lock nut becomes loose or the brass washer gets worn it might do that.  Taking the lock arm off will let you tighten the lock nut down further.  If you cant tighten it down to where it locks the DEC axis take the nut off and look inside and see if there is a small brass washer inside the channel.  if not then it somehow went missing.  It shouldn't be it may simply be a loose locknut.  See the following video for what i mean:

 

https://www.youtube....h?v=rsr7m1ejjVU

 

 

The video does a complete teardown of the DEC axis of the HEQ5-Pro but the part you want to pay attention to is the lock nut removal and removal of the brass washer inside this section.

[marco masento]

I tried but it doesn't seem like the lock nut is loose or the screw is not tight enough. I think that maybe when i was calibrating the top set screw the worm gear might have disengaged with the big brass gear...

[marco masento]

Just to clarify i opened the side of the mount and tried to control the dec axis with my hand controller, the gears turn but the actual axis doesn't move.

[Phil Sherman]

If the motor gears are moving when directed to do so by the hand controller and the Dec axis doesn't move, then somewhere in the gear train a gear is not meshing. This is most likely, from your initial post, because the worm gear is not engaging its mating spur gear. This should also cause the DEC axis to rotate freely when the DEC lock is engaged and you try to rotate the DEC axis using the saddle.

[marco masento]

Ok I fixed it i followed Bignerdguy's tutorial and after reassembling it now the worm gear is engaged again. The problem is that I think that the top set screw's thread is stripped because i can't do the backlash regulation, the top screw just goes in until it starts to turn on itself without going further down or pushing against anything and the Down screw can be pushed all the way regardless of how in or out is the the top one. It's weird because after i fixed my Dec axis i tried to calibrate the AR and did it just fine so i'm sure this screws are not doing what they should.

Edited by marco masento, 13 March 2025 - 09:43 AM.

[marco masento]

Fixed that too the top screw was not stripped but went too far in and was detaching from it's thread so now I changed it with a longer one and I was able to do my backlash calibration.