iExos 100 backlash #iEXOS-100 and polar laser #iEXOS-100


Thought I would share my recent experience with backlash on my Dex and RA. I found some loose screws connecting the Dec to the RA and thought that would help.  I ran the PHD 2  guiding assistant which still reported a huge backlash number.  I looked online and found a YouTube on how to adjust the worm gear backlash and completed that procedure.  On my next semi clear night tried it again and got the same result.   I checked the gears again and they were fine.  I noticed that the belt had a lot of slack in it.  I could see that the motor belt gear would turn in both direction a bit before there was any movement in the worm drive.  I loosened the motor cap screws and shifted the motor to take up most the slack but still not have a bunch of tension on the belt.  I repeated the this on the RA belt as well.  The guiding assistant gave me great numbers on backlash, my settle time on dithering stopped timing out from time to time and my calibration plot in PHD 2 looked great.  So hope this helps others and approach the changes with care as the parts are small and I am sure delicate. 

I am in a light polluted area and Polaris is faint on a good seeing night.  I struggle getting an initial polar lock with SharpCap if I am too far out from Polaris.  Looking through the mount did not work for me.  I have one of the Ebay see for miles lasers that cost about 15 buck and has a cap that makes also sorts of laser patterns.  I unscrewed the pattern cap and turned and aluminum insert to go into the laser and fit into the back of the iExos 100 polar viewing hole.  Now, I check for air traffic first and use the laser to get the mount close and then let SharpCap do its magic.    I know a lot of folks will not have a lathe to turn something like this but it seem a lot of folks have 3D printers and this would be easy to make.  Best of luck.     
W.O 61mm
Clestron C5
Zhumell 10in Dob
exos 100
Zwo 120 mc
Sony alpha 6000
Sbony 60mm guide scope
QHY 183c on order