S/W Focuser

[Astro Imp]

I was out earlier and found the focuser on my Dob really loose. 
When I packed up I realised I could improve things by tightening the Allen screw in the middle of the plate under the spindle. The question is how tight is enough?
The screw I'm tightening is the middle one in this pic.
Thanks in advance.

[Grimbles]

Hi Alan

I had this problem a few weeks ago albeit with the dual speed version, which has slightly different adjustment screws, and was a bit worried at first that something catastrophic had happened. It turned out it was the tension adjuster screw had come loose, which I assume is the screw you are talking about.  Tightening mine did help solve the problem, I then found a set up routine online for the dual speed focuser which I followed is now running better than ever.

I am sure if you look online there will be something for the single speed version, though my thought would be to loosen the locking screw ( knurled one) and then gently tighten the tension grub screw (the middle one) until the focuser moves in and out smoothly without slipping under the wieght of your eyepieces / barlow camera etc.

I'm sorry the above isn't that much help but as I say I am sure there is a proper set up / tune proceedure somewhere online.

Good luck

Martin

 

[Astro Imp]

Thanks Martin, like you I thought something serious was amiss. I have never had this problem before and certainly hadn't fiddled with the adjustment previously.
Good idea to look online, I'll keep you posted.

[Charic]

Undoing the 4 Philips screws will get you access to the 'workings' where you'll see how it works.

If that's a little daunting, let astronomyshed show you instead. https://www.youtube.com/watch?v=ofOSAMlqZWw

You may want to follow his mod too, but  if not, hopefully the link  itself, will  just allay your fears that there's nothing  much under there that can go wrong.

HTH.

[wookie1965]

I did this mod on my 150 and 200p made the focuser really smooth. When you tighten the adjustment screw put in your heavy gear eyepiece, camera whichever the nip it up so there is no slippage and the focuser still feels smooth.

[Astro Imp]

Thanks Charic, I'd just finished watching the link you posted, easy when you know how!!

[Astro Imp]

Thanks Wookie.
"nip it up so there is no slippage and the focuser still feels smooth." That's just the advice I was looking for. Brilliant!!!