Side by Side East West Scope balancing Mod

[nexusjeep]

So,
I posted a while back about wide field with larger sensor or shorter focal length scope and after discussions decided to give it a go with my ED72 as an imaging scope rather than using it as a guide for my LZOS 130/780 and using the LZOS to guide it. My scopes are held in a tandem sided by side scope ring that I had laser cut the reason for them being linked was to guarantee they always pointed the same way and that they could not flex independently of each other which has worked great until now.

The issue was that now I have moved the light 290M guide camera to the LZOS and the filter draw, ZWO CAA and ASI2600MC pro to the guide scope so subsequently the rig has become very unbalanced east to west so rather than adding a humping great counterweight to the one side I came up with an idea. So, after a few days of machining swearing and occasional tantrums and beer I eventually machined the item below.

The new machined parts allow me to use an Allen key to unlock the four M8 bolts that clamp the two plates together and the bearings make sure the plate slides parallel east / west for adjustment of the centre of gravity for the two scopes via the turning of the M6 bolt, this can be seen in action in the video its very slow action so don't get too excited .

Tandem_Side_by_Side by Nick Davis, on Flickr

Tandem_Side_by_side_2 by Nick Davis, on Flickr

Video
Tandem_CG_Adjustment by Nick Davis, on Flickr

Cheers
Nick

[admin]

Hi Nick,

very neat - I like the little screw adjustment device for fine tuning!

I have my side-by-side setup with the mount dovetail holder horizontal in the home position and a Losmandy plate with dovetails bolted at right angles to it (similar to https://altairastro.com/starwave-dual-v ... -207-p.asp) - it doesn't guarantee the alignment of the scopes like your setup, but the side-to-side balancing is easy as you just unlock the mount dovetail a bit and slide left/right. I'm considering a new mount at some point and being able to work with the dovetail at horizontal in the home position is one of the requirements

cheers,

Robin

[nexusjeep]

Hi Robin,
My dovetail is north south as I use it to slide the whole assembly backwards and forwards I have a threaded addon for that that pushes against the saddle so I can dial in the adjustment that way as well for balance in that direction, the side-to-side adjustment worked perfectly last night, and I actually got the best east west balance I ever have had. To top that we actually had a clear night to image as well.

Cheers
Nick