Celestron HD Pro wedge fitting to Pier

[jACK101]

I am planning to build a small observatory with a concrete pier. I plan to use a car brake disc bolted to the top of the pier to accept the wedge. My problem is that I am not an engineer and I need to transfer the Exact configuration of the holes in the wedge mounting plate to the brake disc and then drill and tap to accept the Celestron bolts.

 

Alternatively I could drill slightly oversize and use nuts to secure the wedge.

 

Does anyone have any ideas?

 

Thanks

 

Jack

[michael8554]

Hi Jack

I believe that the wedge has slotted holes to allow adjustment of the wedge's azimuth for PA adjustment.

So slight error in the placement of the holes in the disc shouldn't be a problem.

Get some stiff wrapping paper or thin card and place it over the bottom of the wedge.

Rub over the holes and the wedge perimeter to make a feint impression of the holes.

Go over the impressions with a pencil.

Tape the pattern  over the disc and drill away.

5/16-18 thread I understand.

Michael