Using a Newtonian as a Guidescope?

[Eternal]

OK, here's the deal: I have an 8" Skywatcher Newtonian on a motorised EQ5 mount. I'm getting my equipment together to get into astrophotography and I'm looking at a guidescope. Over the weekend I purchased an el-cheapo Celestron 50mm x 600mm refractor scope for about $50 and it was <censored>!

What I do have is a Celestron powerseeker 127EQ (4" newtonian reflector) and I'm wondering whether that could be used as a guidescope? I'm very concerned about the weight issue (with my mount that is) as it weighs between 1 - 2kg.

Providing I can mount the newtonian OK and my mount is still left standing, does anyone see a problem using a newtonian as a guidescope?

Any help will be appreciated.

[Eternal]

Oops, it's 5" not 4". It's focal length is 1000mm (f/8).

[stephenmcnelley]

Hi Eternal, Problems could include added windage and vibration problems to start with, but if you are a tinkerer like most of us some of the other problems may be solved.

Good luck, its always interesting when people improvise and invent i personally like that aspect of astronomy, you see some clever solutions sometimes.
The mount will not like it at all is a sure bet, rotation around the polar axis on the eq will need the extra counterbalancing but that is obvious, i guess the longitudinal mounting point will be a compromise between C of G and observing practicality.

Little short tube 60mm refractors sometimes go 2nd hand for $$, they do the job to start with.

[[1ponders] (Paul)]

I've seen a number of smaller newtonians used as guidescopes with multiple barlows in older setups (read ancient) so if it worked then, no reason it wouldn't work now.

[Garyh]

I think you will overload your mount. A 8" newt is right on the limit for a eq5 and putting a 5" newt with it would give you only frustration I think...
I mainly use a 70mm f/7 saxon refractor with 3x barlow and eyepiece..
You can get 70mm f/10 skywatcher scope rather cheap and they make excellent guidescopes, and they are light!!
Cheers Gary

[Eternal]

Well I tried attaching my 5" newt last night and it didn't quote fit. I tried to piggy back it by attaching it's tube ring assembly to the tube rings of the base scope but the tube rings of the base scope were too far apart. Although I could have purchased a dove plate and attached the tube rings for the 5" scope to that and then attached the dove plate to the 8" tube rings I really felt that weight wise it would simply be to much.

So instead I purchased a Skywatcher 70 x 700mm F/10 refractor from MyAstroshop. At least I'm now colour co-ordinated!