Mounting Guidescopes?

[riogrande100]

I have a 102mm rings and would like to mount another 102mm rings on top of this setup for my guide scope? what is the best way to do this? should i purchase another dovetail bar and rings?

[pmlogg]

For storage I have to be able to take my guidescope off. To avoid having to realign it every time I have an ADM mini-dovetail mounted on top of my refractors rings. The guide scope rings are attached to a short length of 2" wide x 6mm thick aluminium bar (from ebay). To the bottom of that bar are attached a pair of ADM clamps. So the whole thing just slides on and off. Alignment is maintained and balance can be adjusted by moving it back and forth along the dovetail bar.

When not on my refractor I can put it on my C8 or onto my grab n' go alt az mount, both of which are fitted with ADM rails. The manufacturer in the US is very helpful. For example, he drilled larger holes in the rail I bought so as to take standard 1/4 x 20 tpi screws. Delivery is quick and postage rates reasonable.

[steppenwolf]

I use a second dovetail bar mounted on top of my refractor and this makes for a very solid mounting.

[riogrande100]

I use a second dovetail bar mounted on top of my refractor and this makes for a very solid mounting.

How is the dovetail attached to the primary rings? are u using custom screws? or are they just the camera screw that comes with the rings?

[steppenwolf]

I bought two 1/4" Whitworth screws and drilled out the second dovetail bar to suit. These two screws then pass down through the new bar and into the existing camera mount holes in the top of the imaging scope's tube rings.

[riogrande100]

Thanks Stephen, will order a new dovetail and rings, and let you know how it goes.

[steppenwolf]

Hope it all works out for you as it has for me.

[riogrande100]

I bought two 1/4" Whitworth screws and drilled out the second dovetail bar to suit. These two screws then pass down through the new bar and into the existing camera mount holes in the top of the imaging scope's tube rings.

Ok got 2 1/4 Whitworth screws, have 2 dovetail bars, and 2 rings. how does the whitworth screw into the rings? the screws have quite fat heads which mean they don't sit flush in the rings.

[steppenwolf]

The Whitworth bolts don't screw into the rings - they should have come with 6mm bolts for that purpose. This is the order of assembly:

1. Remove any existing 'camera' thread bolts (these are essentially 1/4" Whitworths and we can argue the toss on this at another time! )

2. Attach the rings for the imaging 'scope to the first dovetail bar using 6mm bolts from underneath the bar

3. Drill out the two end holes of the second dovetail bar so that the 1/4" Whitworth bolts will pass though the bar

4. Attach the rings for the guide 'scope to the second dovetail bar using 6mm bolts from underneath the bar BUT NOT using the holes you have just drilled out - go inboard a bit, drilling new suitable holes if necessary

5. Finally, attach the second dovetail bar to the top of the imaging 'scope's rings by pushing the Whitworth bolts down through the top of the second bar - MAKE SURE THAT YOU EITHER CUT THE BOLTS TO THE RIGHT LENGTH OR USE PACKING WASHERS TO ENSURE THAT THE BOLTS CANNOT PROTRUDE THOUGH THE BOTTOM OF THE TUBE RING OR YOU WILL DAMAGE THE TELESCOPE!