Hello Guest it is March 29, 2024, 12:55:28 AM

Author Topic: G83 peck drilling - rapid plunge height parameters  (Read 22837 times)

0 Members and 1 Guest are viewing this topic.

Re: G83 peck drilling - rapid plunge height parameters
« Reply #20 on: December 21, 2009, 05:45:05 PM »
Hi Guys.

The DSPMC that I use does the same thing with the encoders. It closes the loop and then feeds the actual position back into Mach3. As I said prior and you friend has just said, it is the PID tuning of the servo drive.

If you slow down the rapids you can run a tighter following error. If you retune the PID loop the problem may go away without losing rapid speed. On the DSPMC there is a nice tuning "wizard which graphs the commanded versus actual position so you can see where and how much you are out of position. I believe that Galil has something similar.
 On slow moves I bet it tracks within tenths or better. On rapid moves and if the tuning is not correct, you can be off significantly and in your case the servo will overshoot and if the tuning is far enough out you can actually see it move back and forth until it settles in. Using too much "I" term in the PID will cause it to take time to settle in.

Hope this helps.
Merry Christmas.
Mike.

P.S. The reason I asked, other than I am a nice guy, is that a lot of times people forget to give the final solution to a problem and although only a few people have participated in the thread there are sometimes hundreds of people waitng for the answer.
We never have the time or money to do it right the first time, but we somehow manage to do it twice and then spend the money to get it right.
Re: G83 peck drilling - rapid plunge height parameters
« Reply #21 on: December 21, 2009, 08:20:15 PM »
Thanks Mike, I'll check into this some more - seems like very good info ( I'll see if I can get my friend to help - I've run cnc's for a while, but new to figuring out what makes them go - onsite, real time help will be a huge plus, and might save me from catastrophic mistakes). I always intended to post more, but since I didn't have any real resolution, or even progress, I thought I'd wait. I guess I should've been more impatient - I'm getting some good info. Thanks again, Alex