Sometimes I just don't have time for a great project; this system was originally for my 18" dob.......
I have a Tangent Instruments dual axis siderial tracking system for dobs. Yes, both axis motors make adjustments simultaneously. This is the same system used on the largest JMI reflectors. It interfaces with your existing encoders to provide the following rates:
2) Guiding...+-30% of siderial
3) Setting...12X siderial
Allignment is a simple two step process; point the scope vertically and press the VERT button; then point the scope to Polaris and press the NCP button.
System includes 4 motors (use one per axis ; use two for giant 30"+ dobs, etc), cables, hand controller, and computer box. Will work independently of a PC but can also work with PC
based programs like THE SKY, etc. Includes a simple manual that
shows basic installation drawings as well as how to set the correct parameters for motor direction and ratios.
System is complete electronics-wise; you will have to provide
a bearing to contact each axis, as well as some type of simple clutching system of the alt axis. You could use friction wheels
or a wire/pulley system similar to servo-cat setups.
$265 shipped CONUS. Paypal (add 3%; given purchase priority)
or Postal MO. If you use Paypal I ship to the "confirmed address"
Thanks for looking!
:>) Mark Dearing