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Motor Current Problems?


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#1 maxmirot

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Posted 19 March 2017 - 08:14 PM

Attached File  Capture.PNG   518.67KB   0 downloads

 

 

What is happening? This does not look ok.

 

Max



#2 MarkS

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Posted 21 March 2017 - 01:39 AM

Max,

 

This looks to me like the DE balance is way off. 

Did the system report a Position Error?

Which mount are you using and how heavy is the payload? (My DDM85 seldom registers DE current above 1A)

 

Mark



#3 maxmirot

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Posted 21 March 2017 - 04:47 AM

Dec Balance was perfect.

All sky positions at 2.2 amp scale.

I am estimating about  35 kg payload

 

Max



#4 maxmirot

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Posted 21 March 2017 - 05:03 AM

Two files

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#5 GeorgeCarey

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Posted 21 March 2017 - 10:26 AM

If balance is perfect then it may be that you have the dreaded 'rising current' problem.

My mount had this and had to go back to Austria. I never got a definitive answer to what caused the problem, but it was most likely due to a tight bearing on the DEC axis.

ASA put new bearings in and the problem was fixed.

 

The rising current problem was more common on DDM60 mounts, so I am surprised you have it on a DD<85.


ASA DDM60Pro, homemade 8" and 10" reflectors, QSI 683 camera, Astrodon 5nm filters, Pulsar dome observatory. Website: http://www.geoastro.co.uk


#6 maxmirot

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Posted 21 March 2017 - 06:01 PM

If balance is perfect then it may be that you have the dreaded 'rising current' problem.

My mount had this and had to go back to Austria. I never got a definitive answer to what caused the problem, but it was most likely due to a tight bearing on the DEC axis.

ASA put new bearings in and the problem was fixed.

 

The rising current problem was more common on DDM60 mounts, so I am surprised you have it on a DD<85.

Something is weird with the mount.

It has problems. I have played with balance for hours , it looks  good,  then tracking acts ups.

 

Actually It got Dec balance perfect at 2.2 amp scale. That's perfect at all ALT and AZ positions.

I could never get RA to balance as well. It would be several bars out at bellow 25 degrees E and W.
At 45 degrees E and W it would be excellent , less than a bar.

 

 I using a radial offset weight to get Dec perfect.

 

RA should be easy to get perfect in all position, I think.

But it never is.

 

The current should not ramp up from .5 amps to 2.0 in either axis. Eventually tracking gets flaky. I see it go bad more in RA the Dec. The is like because that most driven element.

 

Perhaps there is some adjustments but I kind of expect it  to go back to Austria. Martin emailed me to do a Skype- team viewer session.

 

Max






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