piggy back on a lx90

[hoops86]

Hey guys im looking for some words of wisdom from you please

Im pretty new to all things astronomy but I recently purchased a used Meade lx90 8" SCT and was wondering if you could advise me in how to go about piggy backing a refractor on it.

I want it for wide field views of objects that wont fit in the view of the main scope. and possibly for guiding my video camera at some point.

I've been reading and the st80 seems to come up a lot... so thats one option... but my first scope was a celestron 70 travel scope that i gave to a friend... i could get that back as he never uses it.... would that work?

Prob a stupid question but... i keep reading about this 80ed thats amazing apparently. If i could pick up a used one cheapish would that work nah? Im guessing it would be too big and heavy? 

Cheers

Chris

[emadmoussa]

[r3i]

I used an ADM mini-dovetail system (MDS) to mount a refractor onto the LX90 that I used to have: http://admaccessories.com/MDS_guidescope_kit.htm

You should also consider a counterweight system help balance things out: http://admaccessories.com/MDS_counterweight_kit.htm

[hoops86]

Thanks for the pics and links. Much appreciated!

That setup looks like it could turn out expensive. I was hoping to keep the costs down if possible. Ive been searching and I found this

http://www.telescopehouse.com/acatalog/Mount_Rings_5___Asymetric_For_8__LX.html.

Looks like the cheapest and simplest option. Would these support a small refractor ok yeh?

If I was to use these rings and the celestron 70 travel scope I think it only weighs 1kg or something would I still need a counter weight system?

[r3i]

Thanks for the pics and links. Much appreciated!

That setup looks like it could turn out expensive. I was hoping to keep the costs down if possible. Ive been searching and I found this

http://www.telescopehouse.com/acatalog/Mount_Rings_5___Asymetric_For_8__LX.html.

Looks like the cheapest and simplest option. Would these support a small refractor ok yeh?

If I was to use these rings and the celestron 70 travel scope I think it only weighs 1kg or something would I still need a counter weight system?

They might work - but I think it would depend on how long the refractor was.  I am assuming that they bolt into the various spare holes that the LX scopes have at either end of the OTA, but it would be worth giving them a ring to verify that.  If that is the case, you'd then need to check that your scope was long enough so that it can be fixed into the rings.

You don't *need* a counterweight system but it helps reduce the strain on the motors/gears and a balanced rig will perform better when guiding.   Perhaps do it in 2 phases: get the refractor piggy-backed first then you can take a view on how good/bad everything is balanced and whether you'd benefit from a counterweight.

[Laurie61]

I bought one of these for my 10" sct 

 http://www.scopesnskies.com/prod/astrophotography/piggy%20back%20mounting%20platform%20and%20rings/combo.html

I would think an 80mm f 7.5 on your lx90 would be a bit much without counter weights? your old 70mm travel scope might be a better, and cheaper, bet. You could also remove the scopes standard finder and use a low mag eyepiece in the piggy backed scope instead, which would save weight.

[Davey-T]

Something like this you mean ? definately  needs counterweights.

Dave

[hoops86]

Cheers for the fast replies guys! All your help is very much appreciated!

Mike - Good shout about the length of the refractor when using they rings! Will need to check that out before buying anything.

Laurie - Good point about the finder scope... as the finder and bracket would prob not be too far off the wieght of the travel scope. And thanks for that link that does look like the best option!

Dave - Nah not like that...im looking for a more hardcore setup lol! Seriously awesome setup you have there!! and no wonder it needs a counter wieght system...it looks like your rig will have its own orbit!!

Cheers

Chris