CPC 800 Counterweight Solution

[Aidan]

Howdie,

I am after a bit of advice with regards to counterweights on the CPC range of SCT's

Having recently bought a Crayford and 2" Diagonal, it has become apparant that a counterweight on the front of the scope is going to be likely.

Looking at what is on the market, the best i can find is the ADM dovetail 3.5lb system at £97! Yes i know this is an expensive hobby but for what i am trying to achieve there must be a way to do this at a lower cost.

Has anyone got a DIY method of attaching a counterweight?

Rgds

Aidi

[Psychobilly]

Are you running the scope alt az or on a wedge? Whilst mine was Alt/Az it wqas quite happy with fair bit of extra gear mounted on it... once i puit it on a wedge it needed balancing...

ideally you want an adjustable setup...

With the pivot point being so close to the rear of the scope you might not need that much on the front...

I have a lenght of T-slot Bar mounted under the OTA and a very heavy brass weight which can be slid along the bar to adjust the balance...

Here's my stupidly loaded setup... and it still tracks ok for long exposure imaging...

How pretty do you want it... Some lead flashing velcroed to the ota might be enough...

[adamsp123]

Peter, you seem to be a few cameras short on your rig

[Psychobilly]

The D50 and the KM5D....

Crazy thing is even with all that lot .. the current draw with the CPC Slewing is tiny....

[Aidan]

Good Grief!! Thats one hell of a loaded OTA! I am running Alt/Az at the moment, but will probably get a wedge in the future.

One thing i was thinking of was along the lines you mention... A strap with velcro and a strip or two of lead. Ok it wont be the most tidy option, but for a few quid it would do the job of a £100 dedicated counterweight.

I set it all up this afternoon and slew the OTA around a few times and it didnt seem to bother it, however i will need to test once aligned and see how it reacts whilst tracking.

Rgds

Aidi

[Psychobilly]

put eh stuff onthe back and slacken off the clutch whilst holding the front of the scope with your finger and try and guage how much out of balance it is... i had to use a digitial "spring" balance...

Based on my own experience I don't expect you'll have too may problems...

With that lot i get the odd creak from time to time but tracks and guides fine.. even when its not properly balanced... clutches would slip when I am too far out of balance...

Peter...

[Helen]

I was looking for something else and found this

Clearance accessories Accessories Celestron counterweight bar assembly - 8 in

any use?

Helen

[Aidan]

I think there is a problem with the website at the moment, but ill check it out as soon as its back online

Didnt think about checking out the balance earlier, ill set it up tomrrow and test it. As for weights, i have found these in Argos:

Ankle/Wrist Weights 2 x 2.5lb. at Argos.co.uk

Ignore the colour... but with the weight already being protected by fabric which will in turn protect the OTA, and with velcro already on them, its a case of finding how to best secure them on the OTA so they dont move as it slews to the zenith.

A pretty cheap work around which could be effective. If i go this route, ill report on how i have gone about fixing them on!

Rgds

Aidi

[Helen]

Aidi,

I too tried the ankle weight solution and it did reduce balance problems. The advantage of a rail system is that it can be fine-tuned easily to achieve perfect balance, and can easily be moved to accomodate any change in kit (in my case if I go from viewing with a small eyepiece to hanging cameras off both the main scope and the guide scope)

Helen

[Aidan]

In time i will go with the rail option, its just a cost thing at the moment. With the recent additon of a Hyperion 17mm, a Crayford and probably a Hyperion 8-24mm Zoom, i need to lay off telescope purchases in order to feed my other hobby... which is also expensive!!

[Mike235188]

Hi. Does anyone know where I can buy a balance bar assembly for cpc800? The only place I can find is in the states...

[faulksy]

the main club sponser flo sell them quite interested myself

http://www.firstlightoptics.com/counterweights/adm-mini-dovetail-counterweight-kit.html

[Merlin66]

For my Lx scopes I used a 12.5 x 25mm length of aluminium channel fixed to the front and rear cells.

Drill and tap a few holes to hold various weights etc ...

This allows re-balancing in Dec....to balance in RA I used the velco wrist weights on the appropriate arm of the fork.

Much easier than trying to balance Dec and RA with an "off set" weight system!