5 replies to this topic

[Rayje1997]

Okay, I think this is the right place to post this.

 

I highly enjoy taking my Skywatcher 200p Classic dobsonian to public outreach events and it is my main visual telescope in my own back yard. The optical quality is quite good, but I HATE THE MOUNT. The axis are just super stiff, especially the azimuth axis, which makes it very difficult to track objects. This means that re-centering while sketching or when I have people standing in line at my telescope takes longer and is just a pain. I think I am going to try a few things to upgrade the original mount, but I have also been considering building a mount similar to the GSO dobs and swapping the altitude bearings out on the OTA to use with such a mount. They look like they should work better, plus if I decide that I want to retrofit it with a goto system I can do that.

 

Before anybody knocks goto dobs because they think I want to do astrophotography with it, just know that if I do any astrophotgraphy with it it will be EAA and planetary. The main desire for a goto dob is just to track objects during public outreach and while sketching. I already have a working setup for DSO astrophotography.

 

All of that said, I would love to hear some ideas for tuning/upgrading the existing mount and also if anybody has built a custom mount (specifically a clone of the GSO mounts) and put their Skywatcher 200p Classic on it, I would love to hear about your experience and/or any suggestions you may have.

 

P.S. the azimuth bolt is already decently loose, so I think the bearing surfaces are most of the problem on that axis and the super small altitude bearings that rely on the tensioner to work are the issue with the altitude axis.

 

Thanks in advance and I hope this helps someone else!

-Jessie

[vtornado]

My Orion dob has plastic pads running on laminate.    For the Az, Check the pads  They should be over the feet.  No protruding staples, no grit.

 

I tried bar soap but that made it worse.  I used WD40 on the underside of the AZ board and it really helped.    I'm a little nervous about using oil, but so far no issues.  I've also heard that a car polish like turtle wax can help.  Some dobs now use PETE pads and I don't think those are as good as teflon.

 

My AD10 has a lazy susan bearing that I really like.  Others hate it.  It has more tendency to run down hill if not level, and weather vaning.  I can use the center knob to alliviate these.  On an older lazy susan dob I had I added some felt the slightly rubbed on the az board and that worked.

Edited by vtornado, 19 May 2025 - 04:18 PM.

[brisdob]

Same issue with my Celestron Starsense 8 inch Dob. On the Az axis I added a large fender washer and a couple of washers cut from a plastic milk container to take a little bit of weight off the pads. It took a bit of experimenting with the thickness.  CD's might work - I may try that.  On the Alt axis I cut a large washer from the plastic milk container and put in on the tensioner side of the mount between the alt bearing and rocker box. Made quite a bit of difference.

Edited by brisdob, 19 May 2025 - 04:25 PM.

[impreza276]

While we all have our preferences, no one is going to knock you for wanting to add goto. An 8 inch dob may be a good candidate for using strain wave drives and Onstep as a goto solution. You can replace the bearings with much larger ones, and build a new base to work with the new bearings. It can be done none-destructively so that you can restore it to original in the future if desired.

[Spile]

My Skywatcher 200P is five years old and the alt/az bearings are ideal for me - not too loose and not too stiff. I haven’t put anything on the Teflon pads either. I have read of folk that had added a lazy Susan bearing and regretted it because it’s too free. I’d take yours apart and give it a good clean but avoid putting anything on it.

[Rayje1997]

My Skywatcher 200P is five years old and the alt/az bearings are ideal for me - not too loose and not too stiff. I haven’t put anything on the Teflon pads either. I have read of folk that had added a lazy Susan bearing and regretted it because it’s too free. I’d take yours apart and give it a good clean but avoid putting anything on it.

Yeah, I can't imagine that a lazy Suzan would be a good fit so I wouldn't even consider that. A lot of the places I observe at have at least a partial incline so I don't want it too loose. I'll give it a clean and see if maybe the teflon pads need to be replaced or something.