Advice needed on 10inch Revelation Dobsonian

[John]

I have been offered on of these at a really bargain price but it's in need of some TLC (it's had a hard life under a previous owner, not the person who is selling it now):

- Primary mirror needs recoating - no scratches but the coating is looking rather shabby.

- One or two dings in the tube plus some scratches

- Owner says the collimation springs could do with replacing

- New tension thumbscrew needed on focusser.

The question is - if I can get this scope sorted, get the primary re-coated (I reckon about £60 or so ?), either straighten or live with the dings and scratches - could it be a decent scope ? - is it worth taking on as a "project" scope ?.

I'll go and inspect it before deciding but I'd welcome opinions on whether it's even worth bothering with. As a guide I don't want to spend more than £100 on "refurbishing" it.

Thanks,

John

[blinky]

Looks like a good project to me. I would think the most expensive bit would be gettingthe mirror recoated. The rest would be quite cheap. Go for it!

[GordonCopestake]

Depending on the price it sounds like a nice scope. GSO optics are usually 1/4 wave perhaps a little more so the mirror set is worth having. Galvoptics or Orion Optics will re-coat it for you but you'll have to build a plywood box to put the mirror in for shipping unless you have someone local to do it. The dings are not important as long as they are not deep enough to impinge on the light path. Take a careful look at the base as they are only fibreboard and if they have gotten damp in the life they will expand and loose all their strength. Not a problem to build a new base but it's a pain.

You can buy new springs and collimation knobs from Bobs Knobs in the states for minimal amounts of cash and I think it would keep you good on those rainy days! Plus 10" of aperture is a lot more than 90mm

[geppetto]

Yep, sounds a good project.

Depends on how much your paying for it though.

Don't be too hasty to get the mirror re coated, you could get

the springs changed first and perhaps flock the tube then try the scope out.

If you make the re coating the very last job there's less chance of it getting

scratched.

Good luck with it

[John]

Thanks for the advice. Is there a straightforward way of getting dings out of aluminum tubes - can they be "rolled" out in some way ?.

John.

[geppetto]

Thanks for the advice. Is there a straightforward way of getting dings out of aluminum tubes

Trick is to rest the tube on a surface with the same profile as the tube and "rub" out the ding with

a ball ended tool of some sort

I once did a similar thing by resting a rounded sheet of ally on a bag of sand for the profile and

rubbed a dent out with the back of a tea spoon :shock: