Recommendation for Max ripple voltage for DC servo drives?

Have you looked at the sine and cosine feedback. I have seen missing one give the same results on other systems. This is just a guess never working with the 7i49 but inductosyn systems will do this and find null every half cycle.

Scott

In the video are you driving the motor closed-loop at constant speed?

Maybe make a degree disc (nound to be one on the net) and plot out the 7i49 angle against actual angle.

Thanks everybody for the suggestions. I will look into setting up the resolver properly and make sure it was done right. I assumed because it traveled the actual correct physical distance as linux cnc shows they would be setup correctly.

I did get a shot of this x axis last night at "15" ipm jog.... actually varied from 9 to 16 by halscope readings...

My silly scope let out the smoke last night when I was trying to view dc and servo output waveforms.... now I will attempt the open heart surgery on this old machine....

Also notable I measure 0 capacitance on the rectified dc input to the servos when off, I think they have a cap but its tucked behind other parts and I can just see the edges of a large cylinder. Maybe the enable input switches incoming power circuit when off?

Also notable I measured a little over 100v dc and I know this system is supposed to be 90v.

So one thought I keep having is how simple it would be for me to just put some brand new dmm servos in here.

Are the old gn6 hiak really worth the trouble? Will I ever get "great" results considering the feedback is on the screw and not motor? I would assume I would have to compromise a bit on tuning for performance to account for the compliance in the drive belt arrangement.... then again I'm a newbie to servo tuning.

A simple but not riskless way to find out:
Take a rectifier, connect big c and feed that into your drives. You can scope voltage on the external. Not super precise but a good guess
Mike