Telescope Focus Drive Shaft

[Mikel56]

At some point in time my sixty year old telescope focus drive shaft has received a fairly significant knock as in the photograph. Other than trying to straighten the shaft would it be possible to buy a replacement / similar unit ?

I also took my first photograph using a camera attached to the telescope. The moon was too bright I think. Tree problem too. My focus is out however it’s not that easy to focus by looking at the camera screen ! Another thing is that as I added an elbow and Barlow I had to adjust the focus. I understand that but there came a point in time when the focus control, wheel adjustment and draw tube adjustment, “bottomed out” mechanically. Removing the Barlow or elbow gave me more “room” when focusing on distant objects. Is this a function of older units, namely a Swift 831.

[Cosmic Geoff]

Given the age of the telescope I suspect that the chance of being able to buy a replacement part is nil. A skilled machine shop should be able to straighten it out for you, if you can find one in your area.

You might be able to replace the entire focus tube assembly, if you can identify a modern one which is compatible, but that could be expensive. People often upgrade the focusers on modern scopes.

As for the focus, telescopes are generally constructed to give them a useful focus range when particular parts are attached. For instance, my Startravel is designed to focus with a diagonal and eyepiece attached, and to attach a DSLR a t-thread extender tube is required.  It is quite common to discover that for attaching cameras you need to shorten the tube (Newtonians) or add extension tubes (refractors).

I bought a T-thread set of extender tubes which in combination offer various lengths of extension.

[Mikel56]

Thanks Geoff, it helps to understand that certain attachments are considered in the design. I also managed to find the adapter you mentioned. Tonight’s project is to use the 9.25 Celestron on Jupiter and hopefully “snap a photo”.

thanks again

 

Edited September 1, 2023 by Mikel56

[Mikel56]

I don’t have a tracking mount hence slight elongation or maybe bad focus. The iso was set at 800 and at 1/3 second. Maybe the iso was set too high.

[Cosmic Geoff]

You have captured the moons but the planet looks over-exposed.