View Full Version : Leadshine EM / AM Anti Resonance & Current Loop Tuning

05-03-2015, 03:01 PM

I've done a fair bit of searching and found very little on this subject, and I was wondering if someone could give me some pointers please.

The setup is AM882 drives, with 4.2A parallel wired steppers, on a 4x4 plasma using HTD 5M belts and pullies (20T) with bearing guided carriages on 2" box section, with the Z having a direct drive trapezoidal 10/2 leadscrew. Power supply is a switched mode supply 42V / 600W. (I need the system collapsible / able to pack away when not in use so some compromises needed to be made somewhere)

I've found a load of infomation on the EM and AM drives for setting them up with regards to the current loop tuning, the best of which seems to be the following PDF.http://www.leadshine.com/UploadFile/Down/EMsm_P.pdf

The drives rune very smooth, and I'm very impressed (yup I was here a few months ago asking about TB6600's which I killed 3 off (muppet born every day) and they were really rubbish so thanks for the recommendations).

I've set up the current loop to the manual and have a very smooth with little overshoot and little oscillation square wave profile, but it does have a fair bit of a sloped lead, but presume this is down to the inductance of my steppers.

Question is, I've tried to fiddle around with the resonance tuning, and got no where as I can't seem to find the point of resonance. Note this is mainly on the Z as the X and Y are HTD5m with 20T pullies, hence 100mm / rev travel, so with the 1st resonance area being somewhere between 0.6 - 1.2 rps (3.6m/min - 7.2m/min), and the second being 1.2 - 2.4 rps (7.2 - 14.4m/min) and the 3rd being 2.4 - 4.8 rps (14.4 - 28.8m) and the drive being belt driven (rubber with steel wire inside the belt) with a table travel of about 1150mm between stops I can't run it that fast plus am not sure how much of the resonance the belts may suppress.

I guess the question really is, what should I be looking for when increasing the pulse generator slider within Protune, one click at a time using the arrow keys on the keyboard. Am I expecting to see the stepper stop, howl oer what as I can't seem to get it to do any of that?

Any guidance would be greatly received.