HEQ5 Pro - Gear replacement

[astroboyz]

Hi all,

Apologies in advance if this post does not land in the right group. I have this Skywatcher HEQ5-Pro mount for quite a while now, even though it's been very lightly used, it appears to have issue when pointing to WEST. I noticed the photos came out with stars duplicated (about 1cm apart on my 15" laptop screen).

I used PoleMaster for alignment and without tracking, it came out pretty good when pointing to North East or North. All photo are taken with 60s or 120s exposure.

I heard about tuning the gears or even replacing them and I really appreciate some advice on this topic, like what/where to buy, how to do or where to find someone providing this service. (I'm in Melbourne, so would prefer someone within reasonable driving distance.)

Thanks so much in advance and looking forward to hearing from the experts. :)

Best regards,
astroboyz

[xelasnave]

Is your clutch (I think that is what it is called) fastened and gripping...the little lever that you engage or disengage with.
Else you may only need to adjust the worm as it had to be just too far out.
Alex

[Sunfish]

Have you tried tightening up the worm engagement as per the instructions in the Astrobaby website if there is play in the movement?

That helped with my mount. The next thing is replacing the gears entirely with the Rowan belt modification which does improve backlash considerably.

Balance is also important every time as slight changes in fittings can change the balance and the motors and gears will struggle in the west particularly if you have forgotten to adjust the weight, where overhead things are fine. I have sometimes forgotten to adjust the weight outward and was surprised when the mount struggled later in the night as the target moved westward.

[luka]

Possibly caused by backlash. You can try balancing the mount so it is east-heavy. This will load the gears and take up the slack in RA. See this (http://uncle-rods.blogspot.com/2017/02/issue-532-astrophotography-with.html) explanation for example.

If unsure how to do it, balance the RA axis well, pick an object in the west and shift the counterweight a bit one way. Take an image which shows the star jump, shift the counterweight the other way (from the balanced position) and try imaging again. See if that helps.

If it works, note that the counterweight must be shifted the other way once you go back to the east side of the sky.