Has anyone heard or have a auto tracker for a dob? If so how goos is it to track planets, nebula and clusters for astrophotograhy?

Look up Poncet tables (platforms) in google. You'll find a heck of a lot of them.

Turns a Dob into an equatorial as far as tracking is concerned. You can image without field rotation as you get if you drive a dob in alt azimuth as some kits allow.

Rick

Go to : www.roundtableplatforms.com Brian Reed now makes a double axis platform. He made a single axis for me and it works great on my XT-12. Just remember that your scope is going to be higher by a few inches. His prices are decent and his work is superior to more expensive ones.

The only modification I made was to replace the bubble level with one that measures in all directions. Levelling is where I spend most of the time during set up.

The scope will go through a sweep or swing for about an hour or so and then it stops and you have to reset it. It is worth the investment. I used my binoviewer and zeroed right on Plinius for several hours about 10 days ago. Looked great and neighbors were shocked. I put it on M13 and went inside for a 20 minute snack and it was still there when I returned.