rigid and rough RA-axel on GEM

[galmies]

I have an german equatorial mount which i got from my friend. Problem is that the RA-axis (which rotates the axel where the telescope is attached, if i'm right?) has spots where it is easy to turn and spots where it is noticeably harder.

All axels on mount also go stiffer when i take it to outside, it is probably just the grease freezing?

But is there any easy fixing solutions?

[Bizibilder]

Does the mount have gears (possibly hidden inside the casing)? If so it sounds as if they are binding and need to be adjusted. Could you say exactly which mount it is or provide a picture? It would make it easier to help you.

[galmies]

I found out that the mount is from telescope+mount combo sold by lidl, it is called bresser skylux and here is picture from it.

[Bizibilder]

That style of mount has each axis operated by a worm wheel arrangement and these can easily be adjusted. That should clear up any "tight spots".

[brantuk]

You may find this review of the Lidl scope interesting and answers a few thing - in particular the "stiff" controls:

Lidl Skylux 379 Telescope

[galmies]

So there should be some bolt which adjusts the tension of those worm rings? I read that article but didn't understand which bolt and where. Should it be small or big and do i need to take that mount into pieces to adjust that?

[Dave S]

I have the same mount bought second hand. I found that the grease on this model is awful and has gone like sludge. I regreased with a moly based product which cured the stiffness. Unfortunately the previous owner has stripped the teeth on about an eighth of the RA gear. So until i can find a replacement it's useless.

Dave..

[galmies]

So i should try my luck and open all bolts i found, inspect that everything looks ok and then try to reassemble it? Hopefully i won't broke things more when i have time to do that .

Edit: What would be the worst thing or things to do for my mount when disassembling it? I haven't owned nor opened any mounts before.

[Bizibilder]

The bolts I've marked should get you into the Dec worm and allow adjustment (maybe just loosen them and "jiggle about" and retighten would do!). There should be similar bolts to let you get at the Polar axis worm.

Hope this helps.

[galmies]

Thanks for all, I took that part out and put it back in and those tight spots are now much less tighter.

Btw. do you have any recommendations for the grease? I read on internet that greases used in car chassis would be good, is this true? It should be pretty thick, but not too thick and it shouldn't freeze in low temperatures. Is there more things to take into account?

[Bizibilder]

Lithium Grease is the stuff to use - either "dollop" it on by hand (not too much, mind!!) or use an aerosol. Places like Halfords will sell it.

[galmies]

Looks like there is many greases which sell them as lithium based and their temperature ranges vary from really hot to -15, -20 and -25 celsius. Hopefully those -25 celsius greases won't go stiffer than the current grease in -20.

Umm, should i use some paint remover to get that old grease out from there. It looks like stuff that doesn't move anywhere without a fight

[Bizibilder]

I would try white spirit or meths (or both!) first - just wipe off as much as you can with kitchen paper first.

[galmies]

After hours of work, grease, paper, cleaners, screwdrivers, wrenches and everything what was under my eye, it looks like i still have an working telescope mount! The axels are now so light to use that they almost feel like a toy. Looks like i should try to realign that worm thingie again, but it works.

Thanks for help. Now i just need to wait for the sky to clear so i can see if that grease works in low temperatures too .

[Bizibilder]

Good Job!! Make sure that you have eliminated, as far as you can, any backlash between the worm and its gear. Then just wait for those clear skies!!