Hi Ken,
Looks like Super Polaris is very similar to my LXD75 (or Bresser.. or Meade... ).
It is pretty good in terms of transportability.
But the PE was killing it.
I wanted to add ST-4 guiding port to DUO controller that came with the mount and sort this out, but when having a closer look at how the buttons are connected and what they do, I found out the controller has a bug in firmware or just h/w problem: pressing the RA forward button increases motor speed 2x (which is OK) but backwards button did nothing (and in this case the motor is supposed to stop) so this controller was totally useless for guiding as it was.
Unfortunately I couldn't find the schematic or firmware listing anywhere on the net..
Interestingly, manufacturer did some wire modifications on the back side of the board.
One forum member gave me a following link some time ago:
http://bbs.astron.ac.cn/forum.php?mo...light=&page=10
Unfortunately there is no mention about DUO controller (board is marked as "KM JH DK-3").. or at least I think there isn't.
Google search for "KM JH DK-3" resulted in this link:
http://picasaweb.google.com/10000095...q3X2Zt-x9AnMwA
There were no wire modifications shown on this board !!! (in other aspects mine seems to be identical)..
Because DUO controller has two separate processors for RA and DEC axes, and the modification done to my board was not consistent for both processors, I tried to match it.. and voila, now the Left button stops the RA motor, and the controller is now suitable for guiding (pending the addition of ST-4 port).
However, the problem with high PE would still be there without guiding, so I decided to try belt modification (on second picture attached) in hope it would reduce the PE by down to 1/5) and to try to use my own simple controller I designed some tome ago, because now I need 5x higher motor speed.
The immediate challenge now is to finalise the code for 68HC705KJ (attached).
It's supposed to have the (almost) same functionality as DUO controller (DUO controller has two separate processors for RA and DEC axes, my solution has only one - which means my controller doesn't accept both guide commands at the same time - telescope guides only in RA or DEC ) ... I still need to test it.
Or, I will go with one of available arduino solutions.