RA axis lost connection

[Mirandola]

Hello 
My friend has problem with his DDM85 mount. He has Windows 7 64 bit version and Autoslew 5.2.0.4 installed. From time to time his DDM85 looses connection with RA axis during slewing and  stops. The setup is perfect balanced with Autoslew software. PIDs are also quite good. 0,04 arcsec ticks in tracking mode is what we see on graph. In max speed everything also looks good. 

When we uncheck "Filter noise on" in "manual tune" window, the RA axis does not loose connection, but the mount is much more noisy.Any solutions?

Another problem is with Sequence software. When we connect all soft and start MLPT routine, the mount slews, then it makes exposures and.....nothing happens. In bottom menu wee see command that file can't be loaded ( I think CCD fits file is not loaded to plate solve). In MaximDL window, of course, we see that exposure is done, so communication between sotfware is working. I have DDM60 and have never seen such command. Waiting for your help.
 

Edited April 5, 2014 by Mirandola

[Renims]

interesting topic

[prefetch]

>From time to time his DDM85 looses connection with RA axis during slewing and  stops.

 

i think it would be helpful if you would post your friend's autoslew log that shows the error message when this happens.

 

>When we uncheck "Filter noise on" in "manual tune" window, the RA axis does not loose connection, but the mount is much more noisy.Any solutions?

 

sounds like you should keep the filter noise option checked.    

 

> In bottom menu wee see command that file can't be loaded ( I think CCD fits file is not loaded to plate solve).

 

one idea here is to find the .fits file in your file system and confirm that it is there, and also confirm that the file permissions are such that it can be accessed/read by other users (or applications.)

[Mirandola]

Both problems solved.

1. DDM85 has 2 counterweights. The bigger one was placed upper and smaller one lower on the shaft. We change them  and the problem dissapeared. Interesting ...  

2. We did not fill CCD horizontal and vertical pixels data in CCD setting window.

[Roger]

I cannot believe that this weight swap has made any difference to the underlying problem.  Generally less flexure and fewer low frequency problems will be experienced if the heavier weight is nearer to the fulcrum (as you had it before the swap).  The underlying problem sounds more like the one Lukas describes in "losing USB..." , eventually resulting in a return-to-base repair, with which he is now very pleased.

 

I hope I am not the prophet of doom, but I fully expect this problem to return to haunt you.

 

Post hoc ergo propter hoc.

[lukepower]

Hehe Roger, your prophecy on the electronics were right

 

I think that the swap itself made probabily not a big change, except maybe that the balance could actually change ins ome unusual attitudes, depending on the tube diameter, but that's just a guess. Honestly I think that the rigidity of the tripod and mount-tube combination are essential. I once tried the system with a loosened pier, man that was a funny sound in the observatory No way to get those vibrations out of the system. 

[Mirandola]

You are right Roger. The problem is not solved. Autoslew shows position error and  RA axis  stops. When we click button with error (I don't remember the name of it) which is placed above "Write log to file" the RA axis is connected again. Beside, we got another problem with sequence. We created a 50 point grid and after 12 exposures autopoint file was created. Sequence missed 38 points and decided ...the work is done.

Edited April 6, 2014 by Mirandola

[prefetch]

mirandola,

 

you really need to post a log file.  iirc, it's in the servo menu where you can set the log to have extra information in it.

[Renims]

ON CLOSED. - CORRECTED

Edited April 6, 2014 by Renims