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Tandum
14-02-2011, 10:38 AM
I picked up one of these scopes on Saturday and had trouble getting balance with a camera and filter wheel hanging out the back. To trial it, I had it on a SBS plate with a tak FS60 as a guider and we had to hang a counterweight off the front of the RC8 and add a 3rd weight to the mount and it still seemed a bit dodgey to me.

Back at home in daylight I tried again and replaced the front counter weight with a stellarvue 60 guider, removed the SBS plate and came back to 2 weights on the mount shaft. It seems to be balanced but haven't had it outside like this yet.

I was wondering how longer term users of this arse heavy scope are balancing them?

TrevorW
14-02-2011, 12:08 PM
I use an ED80 for a guidescope and have no issues with balancing although I use a OSC camera so don't have a much back weight as you.

Cheers

gbeal
14-02-2011, 12:24 PM
I'd say the latest method is the best to be honest Robin, keep the weigh as close to the pivot as possible, and hang the guider out the front like you have. Why they make so much back focus in an imaging scope is beyond me, my AT8" is the same.
Gary

Tandum
14-02-2011, 10:36 PM
Cheers guys. Trevor I guess you have the ed80 piggybacked. I suppose if I got a lighter camera I could just move the guider to the top. This qhy9/wheel/filter combo must be almost 1.5 kilos, prolly 4 times the weight of a OSC. But as gary says, keeping the weight low seems to be the go, it appears to cut the number of counter weights and they ride higher on the shaft which has got to be a good thing. Proof is in the images I guess :)

pvelez
15-02-2011, 12:35 PM
Robin

I have a heavy imaging rig - ST8300 + FW8 - hanging off the back of mine. I also have an Optec focuser which adds more weight.

I piggyback my short-tube ED80 on top and have a counterweight under the nose of the scope - its a reasonably heavy weight. It seems to balance ok - if anything it is not consistent between east and west - I suspect because of the location of the motor for the focuser.

Agree with pushing it as far forward as possible

Pete

Paul Haese
15-02-2011, 09:49 PM
I used a Losmandy dove tail plate suitable for a C9.25 which is a lot longer than the scope. I then installed some parallax rings up front and this gives me the room to balance the scope with the longer dove tail plate.

allan gould
15-02-2011, 10:21 PM
I know they say its to allow for a long imaging train but I think they should redesign the tube to allow for far, far less back focus. Just my 2c worth.

beren
16-02-2011, 02:07 AM
I use this (http://www.optcorp.com/product.aspx?pid=439-735-183-184-3452) :)

pmrid
16-02-2011, 06:41 AM
I have used one of these also but found them prone to shake a bit. The way the shaft connects to the mounting block is not particularly secure and the weight that screws up and down that shaft is fairly loos so that it will wobble if you don't add a couple of locking nuts. A bit of "re-engineering" will sort out those couple of issues though.
Peter