|
Gday Robert
To do it properly requires a 2 stage process.
The first is to get the DEC axles perpendicular to the RA axle.
The second stage is to get the OTAs optical axis parallel to the RA axle.
Stage one isnt a simple exercise and cannot be done properly on a wedge.
Stage 2 can be initially validated by doing a spin test whilst looking at the triangular asterism at the pole.
Ie set the OTA to DEC = -90 and DEC axles horizontal
Note position of stars on either side ie L and R sides of the EP relative to the stop.
Rotate in RA by 180deg so that the DEC axle is again horizontal
and again note position.
You may need to tweak the DEC slomo to get the OTA perfectly at DEC = -90 whilst doing this spinning.
Once done
If they are the same relative distance away
then your "second stage" alignment is OK.
When its truly correct, you can actually spin the scope in RA
and the stars of that asterism should trace circles inside the EP.
Note. Stage 2 aligning can be achieved, even if stage1 aligning is incorrect, but unless stage1 aligning is correct, gotos will still be off.
Andrew
|