On Wed, Apr 8, 2020 at 06:54 PM, Kane Mcvicar wrote:
This is a good strategy that is not in wide use yet.
The motors you quoted should do a decent job with very good resolution, using 1/16 microsteps.
And with that, you should be able to get 2.5 to 3 degree/second, so not slow at all (but not super fast either).
My concern would be the RPM of the motors. If you use 10:1 for RA, and 30:1 for DEC, the RPM is lower.
In that case 1/32 microsteps will be better.
The geared motors allow using the 1:1 pulley which need less space, and have less chance of obstruction.
Most imagers prefer not to have any backlash, and therefore opt for 400 steps motors and a 3:1 pulley reduction.
That leaves out only the backlash in the motor and in the worm/wheel.
But even with some backlash, things do work out. OnStep can compensate for backlash, and Ph2 too.
So worth exploring this approach.
See above. That is what most OnStep users do.
In that case, RA should work with 3:1 with good resolution.
However, DEC would be a challenge since you need 6:1 for a decent resolution.
Finding a pulley that is 6:1 will be a problem.
In the Wiki Showcase page, check the EQ3 and CG-4 mounts, some have a 65:1 worm wheel on DEC.