Tracking problem

[apolkowski]

Hello,

I have been using my ASA DDM60 for over a year without issues. Unfortunately after last session in April the mount started to behave strange. It finds the home position, then I sync it to a star, then the tracking starts, but when I make a photo, the stars are lines, not points. When I stop tracking and make continuous 1 second exposures, I see stars moving as the the sky moves. When I start tracking the stars are moving in the oposite directions which means that the tracking speed is higher than it should be. At the same time the position of the telescope shown in Autoslew does not change as the mount would be pointing perfectly to the star. 

Location of the scope is taken from the GPS and is correct. Local time is OK too.

Servos tuning completes without errors and manual tuning shows that the mount behaves as it did before. Balance is OK.

The mount is set on a permanent pier and i did not change its position.

I did the factory reset, new Autoslew installation, clean installation with deleting data files, and I tried to use another PC. This did not help.

Do you have any idea what else I should try to fix it?

Regards,

Andrzej

[robertp]

Hello Andrzej,

very strange behaviour! I once had a problem with tracking speed being noticably off and tested everything I could think of. In the end, the problem was a parameter in the Cl-servo.ini file that obviously got corrupted. I only found it after comparing all entries in the ini-file against those of an older version, that I still had. The paramater was "Encoder Resolution per Revolution (or mm)" of the RA-axis. Somehow, the value was wrong which lead to the axis moving too slow or too fast. I had no clue, how this could happen but as in your case everything was fine and the next day the problem occured.

When you did a new installation of autoslew, did you also delete all ini-files or did you just deinstall autoslew and then installed it agains? In the latter case, autoslew takes over the old ini-files. Maybe you can deinstall autoslew again, delete all files in ProgramData/ASA/Autoslew (or better rename the directory) and then do a clean install. Or if you still have an older version of the Cl-servo.ini compare the entries.

Other than that, I can't think of why your mount should behave so weird.

Hope you find a fix for your problem,

Robert

 

[robertp]

Hello again,

sorry, I just saw that you already did a clean installation (even on a different PC), so a corrupt ini-file can not be your problem.

Robert

[apolkowski]

Thanks @robertp. I wonder if ASA has any "residual" memory in the mount that can influence the behaviour of servo drives.