Restoring Homemade 10"

[GG (Garret)]

So I picked up this scope/mount/chair setup for $50 about 6 months ago, it had been sitting in the rain so the barrel was stuffed so I thought I should save it.
I haven't really touched it apart from breaking it all down getting some measurements (hard due to the tube being stuffed) and storing it.
10" mirror and I believe it is F5 but have to double check by measuring the focal length properly.

http://imgur.com/a/oUuWy

Never built/repaired a scope before but have been doing a fair chunk of reading.

Primary Mirror seems in okay shape with some of the coating coming off around the edges.
Primary mirror cell is fine, only 1 wingnut missing.
The Secondary Mirror is 2.14" and is in a bit rougher shape with a chip in a spot where it was held with a bracket.
Spider is a little bit damaged but may be repairable.
Finder scope should be okay.
Focuser moves okay also.
Mount moves fine and also weighs about 140kg, needs a little bit of work done but it was motorized at some stage by the looks.

I have found one seemingly decent site in https://stellafane.org/tm/dob/index.html

Where should I start, it seems like that site has a pretty good list but it's a lot to take in.

[torana68 (Roger)]

nice, was on gumtree in wa?

[GG (Garret)]

Originally Posted by torana68

nice, was on gumtree in wa?

Yep

[Rod]

Hi Garrett

I would start by verifying the main mirror is of good quality. if you have not tested mirrors before see if you can star test the mirror with a ronchi grating. This is a relatively coarse null test that is easy to do. Look for very straight lines when you are observing the star.

I would replace the secondary if it is damaged. Secondaries are relatively cheap. If the focuser is only 1.25 inch I would plan to replace it with a 2 inch focuser at some point. These come up regularly for sale here and again are often not expensive.

Once you are satisfied with the optics, your main task is replacing the tube. You can buy a cardboard tube, make a truss tube or a metal closed tube. My last two telescopes have had octagonal tubes made from 6mm ply. These are easier to build than I expected and are quite light.

I would use a program like Newt for The web to work out the tube dimensions and where to place the focuser, what size diagonal to use etc. it's located here:

http://stellafane.org/tm/newt-web/newt-web.html

After that I guess you need to decide whether to use the existing mount or build something more portable like a dob.

Hope that gives you some ideas.

Rod

[torana68 (Roger)]

get yourself a new tube and put it all back together and then see how it goes. Any writing on the primary mirror?