PDA

View Full Version here: : Balancing a SCT on a wedge


pmrid
06-02-2009, 01:31 AM
I'd be grateful to hear people's best suggestions for balancing a wedge-mounted LX200. I'm buying a 2d Bintel counterweight that seems well enough suited to a scope that is used primarily in the fork-mount in an Alt-Az configuration. But what about when the scope is being used equatorially on a wedge?
I find it hard enough to figure out how to set up my LX200GPS for southern hemisphere - but assuming that I can get that figured out sonn enough, I want to start putting a new guidescope on it and then a 300D. Thiose each add weight on a different axis and my question is whether a 2d system is workable with a wedge or whtehr it tends to limit the movement of the scope in Dec or RA because it bangs into things.

Peter

acropolite
06-02-2009, 07:11 AM
Peter, most of your questions can be answered by visiting Pete'e astronomy site (http://www.users.on.net/~pbl/art_adm_review.htm), he has images etc which show how he set up his LX90, guidescope counterwieght etc, you'l have to hunt around the site a bit but most of the info you need is there. Most people use an ST80 for a guidescope as they're quite lightweight. The weight system is designed in such a way as to not interfere with the forks.

Merlin66
06-02-2009, 07:23 AM
I find it easier to balance in RA and Dec independently.
The RA balance can be achieved by adding weights to the fork arms; then balance the Dec with weights on the usual dovetail rail.
This is much easier to control and achieve a satisfactory outcome.

GrampianStars
06-02-2009, 07:37 AM
G'day Pete
here's the setup instructions
balancing 3D is a must
(1) point scope east or west forks (horizontal) above each other
release dec lock add or remove weight close (along tube) of OTA to stop swing through.
(2) point scope north forks (vertical) slide weight away (out) from OTA to stop swing through.
must be done in this order

aworley
06-02-2009, 12:00 PM
That is what I do and I get good results for balancing.....Mike from Bintel showed me that method and it is simple and works....!! I have an LX90 on a wedge with an ED80 on top...

Alex

:)

Omaroo
06-02-2009, 12:08 PM
Because the Dec motor and gearing is held in the right-side fork arm it's heavier, and upon RA clutch release will swing that way in RA. I used lead weights stored inside the battery compartment of the left fork arm to counteract this. Mine was a 12", so I guess they're similar...

AndrewJ
06-02-2009, 12:27 PM
Just another fairly simple option for a "true 3d" system
Piccies added show a mod to a Losmandy slider i did for a mate,
to allow the weight bar to be swung to balance RA
Method
1) Set DEC axle horizontal and lock RA clutch
2) Loosen DEC clutch and point OTA vertical
3) Move weights in/out on rod till balanced
4) Rotate OTA so its horizontal
5) Slide weights along rail until OTA is balanced
The OTA itself is now balanced
Now point the OTA vertical again and lock the DEC clutch
6) Loosen the RA clutch
7) Loosen the weight bar lock and swing the rod sideways till RA balances
8) Lock the weightbar and you have full 3D balance
No extra "tacked" on weights required and its easy to reset as reqd

Andrew

pmrid
06-02-2009, 07:07 PM
Guys, thank you. It's a great thing about these forums - that complete strangers are willing to pitch in and help one-another. OK. That's enough gushing; but you all know what I mean.

Peter