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Old 02-03-2018, 08:07 AM
Wavytone
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Wavytone is offline
 
Join Date: Jul 2008
Location: Killara, Sydney
Posts: 4,147
Hi Malcolm, it’s from Astro-Optical, and it’s a later version of their “Samson” or “Goliath” mount.

It had bush bearings for each axis, the RA circle is the white disk with numbers like a big protractor - slides onto the end of the polar axis, which should have a worm wheel and worm drive driven by a 240VAC synchronous motor for tracking.

The mount say on a pier which it appears you have, with three metal legs that bolted on the bottom of the pier. These legs had screwed feet at the ends for fine adjustments.

Adjusting latitude was crude - use a spanner to roughly adjust the tilt. Then the tripod feet are screened up/down to make fine adjustments.

Adjusting azimuth ... looks like you have that part on the top of the pier.

On the dec axis there was a large metal plate with cradle to hold OTA. Originally it came with a metal strap to go over the OTA but I found this was not very satisfactory and on mine I used a length of seatbelt webbing with loops sewn in the ends - this was far more satisfactory and kinder to the OTA - mine was a 10” Sonotube cardboard thing.

The motor was driven by a mains powered “drive corrector” (box of electronics) which typically puts out a variable frequency 240VAC output for the RA motor, such that the frequency can be altered between about 45 to 60 HZ to achieve slow-motion in RA (mainly for photographers).

The little box with the buttons is the handset to operate the RA drive corrector.

I see yours has the dec drive, consisting of a tangent arm under the cradle driven by a screw thread to move the arm. Most of us had a manual flexible cable to turn that shaft manually, in that era very few ever had motorised the dec axis.

As for the OTA ... I see you have a mirror, that can be recoated. Keep an eye out for a three vane diagonal holder, and a 0.965” focusser (probably Unitron or Polarex), though I guess you’ll replace that anyway with a modern one.

Before powering this up I’d strongly suggest get it checked by an electrician - if the insulation on the wiring has gone stiff with age and broken, or there are wires hanging out it could make the whole mount dangerously live with mains.

If you wanted to get it going again it’s usually not hard to find stepping motors and gearboxes that will work nicely from 12 VDC.

Last edited by Wavytone; 02-03-2018 at 10:02 AM.
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