Re: ATM Alt-alt telescope mounts and image rotation - long post

["James Lerch" <jlerch1@tampabay.rr.com>]

Mel,

Let's see if I got this right,

If I build an Alt-Alt scope, and place it on a base that rotates in azimuth,
motorize all three axis, I can have a scope that will track Mars (while at
opposition) all night long, with no field rotation, no polar alignment pains,
and dang simple construction to boot?

If this is correct, can you get Scope.exe to control 3 motors directly (as in no
Saa1042 field rotation chip)?  Lets say use pins 14-17 to control the third
axis?  My thinking is were going to want micro-stepping in all three axis, yea?

Otherwise, if we can live with half stepping on one axis, Scope.exe and your
control board is already capable of handling this type of mount, yes?

I've got an 11.25" F/7 primary that will be ready for an OTA and mount soon.
The goal was to have it ready for the upcoming Mars season.  I had originally
planed an Alt/Az with a rotating OTA to get rid of field rotation on the CCD,
but an Alt/Alt/Az would be SOOO much simpler to build!!!!!!!!!!!!

I just had a thought, I could use my Bino-scope alt/az mount (minus the
Bino-scopes) add a second Alt axis at 90 degrees to the existing Alt axis, and
I've got 2/3 of the work already done! :)

With regards to your question "I have the software routines - any takers <very
big grin>?" I'll raise my hand and do my best 'Horseshack' impression from the
TV show "Welcome Back Carter" <G>

Take Care,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction,testing, and coating site)