CG5-GT How do you balance you scope?

[spaceboy]

Hi All

Question time for me today so thank you everyone who is helping me out.

My question is how do you balance your scope on a CG5-GT mount with out having to do another star alignment?? I see there is some thing in the manual saying you can undo the clutches for balancing but it doesn't explain anything about the procedure ensuring you don't loose alignment.

SPACEBOY

[Martin 2]

Get all the balancing done before you start the alignment etc.

If you release the clutches after aligning you will need to go through the alignment again.

Martin

[spaceboy]

How do you balance the scope between EP changes GOTO mounts are more of a pain than they are worth.

[Moonshane]

maybe some kind of counterweight that you add to the tube for heavy eyepieces? I agree on the hassle factor - dobs rule!

[JohnnyD333]

Im curious myself about this. Once I balance my mount and align it, I have to attach a camera and a guidescope which weighs considerably more than an EP. I dont want to put unnecessary strain on the motors. Can I simply slide the telescope down the rings holding it in place?

[bamus]

How do you balance the scope between EP changes GOTO mounts are more of a pain than they are worth.

how heavy is your EP? I have never bothered to balance again when EP was changed.

[spaceboy]

how heavy is your EP? I have never bothered to balance again when EP was changed.

Don't ask you really don't want to know the difference between my lightest and heaviest EP. Re-balancing will be essential if I want my scope to remain in an up right position. I knew I would regret going down this road when I purchased my last EP. The views better pay off

[spaceboy]

Can I simply slide the telescope down the rings holding it in place?

The problem is the OTA has to swing freely to establish the COG. To do this you have to loosen the clutches. No sooner you do this the GOTO looses track of where it is.

[spaceboy]

maybe some kind of counterweight that you add to the tube for heavy eyepieces? I agree on the hassle factor - dobs rule!

In my mind this is the way I wanted to go but the total added weight between the EP and counter weight is going to be shocking and I doubt very much up to the capability of the poor mount. And yes Shane dobs on EQP's rule

[Carbon Brush]

I am ssuming here it is a bit of counterweight and tube sliding only.

Masking tape and biro.

Put bit of tape on the 'scope' and 'mount' parts of each axis.

Draw a biro or pencil line to link them.

Loosen the clutches, attain balance.

Tighten clutches to align again with biro marks.

Any errors are usually small enough to put right using sync.

Messrs Heath & Robinson showed me this one.

If you rotate the OTA, then whether you can get away with this method depends on how near together the OTA mechanical and optical axess are located.

[spaceboy]

This was another idea that entered my mind but using glow in the dark tape rather than masking tape. I admit I never gave the OTA orientation a thought. I don't have the usual 3 tripod legs to worry about but I still don't fancy it running into what I do have.

[dugpatrick]

... Once I balance my mount and align it, I have to attach a camera and a guidescope which weighs considerably more than an EP. I dont want to put unnecessary strain on the motors..

Here what I do: I balance the mount with the camera and guidescope attached. I align/calibrate using liveview. If you enable the liveview grid then it's easy to center the stars. If a star isn't visible on the liveview display then I us a finderscope to center the star, then I go to liveview to finish alignment.

Bottom line: I never use an eyepiece unless I want to use the telescope in visual mode. The only change to the balance of my scope is the finderscope, which I remove before imaging.

Doug

[JohnnyD333]

Thanks Dug, Ill give it a shot once the clouds clear

[ollypenrice]

Never in a million years would I dream of rebalancing between eyepieces. It just isn't necessary in visual use. If you like, choose a compromise balance point in Dec between heaviest and lightest.

As for putting on the camera, you can just balance with the imaging rig as it will be used and then do the alignment out of balance with an EP. In fact I find I can do an alignment quite happily from a well aligned finderscope nine times out of ten. To perfect it, align from the finder, expose a pic, centre using the camera, and Bob's your Uncle.

Olly

http://ollypenrice.smugmug.com/

[spaceboy]

Never in a million years would I dream of rebalancing between eyepieces. It just isn't necessary in visual use. If you like, choose a compromise balance point in Dec between heaviest and lightest.

I just can't see it working Olly. I will be going from 0.33lb to 2.2lb on a GT mount that is already at it's maximun load capacity. Would balancing the OTA on the mount at a happy medium not mean that no matter what the EP in the focuser there is always an uneasy load on the worm/gears meaning inaccuracies in the GT precision as well as risking unnecessary flexing of the OTA walls and possibly collimation issues depending on OTA orientation???