Hello Guest it is September 21, 2019, 02:01:37 PM

Author Topic: Servo for lathe spindle ?  (Read 18199 times)

0 Members and 1 Guest are viewing this topic.

Re: Servo for lathe spindle ?
« Reply #70 on: October 05, 2014, 02:56:13 PM »
 Hi,
No it is impossible to get 7000 in Mach.Even with 3000 a lot of vibration and the servo behaves unpredictibly.
I went back to original settings of the drive.Then set it for speed mode.Then messed around all day with it.Lowered Mach speed to 1000rpm.Now i can jog smoothly up to 60%.Make it 65% and the drive vibrates hard back and forth.I am trying to read how to use scope that is integrated in Delta's software for tuning the drive.Trying to put Notch filters values where the resonance happens to smooth it out further...
By changing the gear it should increase the torque (i think) because i was thinking of using a bigger 60 teeth gear on the ballscrew so the ratio (having the same gear in the servo i.e. 24teeth-and having the same rpm in the servo)would be less turns for the ballscrew but with more torque isn't it?I was thinking this would possibly smooth things out a bit...

Tasbiz

Offline Hood

*
  •  25,853 25,853
  • Carnoustie, Scotland
    • View Profile
Re: Servo for lathe spindle ?
« Reply #71 on: October 05, 2014, 03:06:07 PM »
Ok I misunderstood regards the reduction, I still do not think it will help, it sounds like you need to play around with  the tuning in the CSMIO.

I am assuming your tuning from within the servo drive is good? ie when moving from the servo drives software itself.

Might be worth turning off the constant tuning in the drive, that is if you have that switched on and trying the semi auto mode or manual mode.

Hood
Re: Servo for lathe spindle ?
« Reply #72 on: October 05, 2014, 03:31:56 PM »
 Tuning from the servo drives software is perfect.Always without a problem-even from the start...I wish i could get so smooth movements from CSMIO as well...
I will try to semiauto..

Tasbiz
Re: Servo for lathe spindle ?
« Reply #73 on: October 06, 2014, 02:41:45 PM »
 Making some progress using manual and semi-auto tuning methods...
I have a strange problem: No matter what i do with the tuning,when i jog from mach or csmio what happens is jogging to the right is smooth but when jogging to the left the servo is very much faster and just by a short stroke of jog it picks up speed and goes and hits the left limit button...
Any ideas?

Tasbiz
Re: Servo for lathe spindle ?
« Reply #74 on: October 06, 2014, 03:53:34 PM »
 That is when i jog with 100% slow jog rate...

Offline Hood

*
  •  25,853 25,853
  • Carnoustie, Scotland
    • View Profile
Re: Servo for lathe spindle ?
« Reply #75 on: October 06, 2014, 04:35:01 PM »
Something strange there, almost like your encoder signal is fine one way but not the other.
Do you have this problem at lower rates, maybe 50% in CSMIO tuning screen?
Have you tried just commanding a small move back and forth in the tuning screen to see if the distance is the same both ways?

Hood
Re: Servo for lathe spindle ?
« Reply #76 on: October 06, 2014, 04:39:54 PM »
 No up to 55% everything is smooth and normal.
After some more tuning it appears that i need to increase the acceleration a lot in Mach motor configuration.Someting like 3000 or even 5000 acceleration rate.That is with 1000 motor speed.That way jog works at 100% both ways.Is that normal?

Tasbiz
Re: Servo for lathe spindle ?
« Reply #77 on: October 06, 2014, 04:40:54 PM »
If i try then to increase motor speed to let's say 1300 in Mach same thing happens...

Offline Hood

*
  •  25,853 25,853
  • Carnoustie, Scotland
    • View Profile
Re: Servo for lathe spindle ?
« Reply #78 on: October 06, 2014, 04:46:11 PM »
3,000 or more for accel seems high, suppose it depends on the machine, on a very light machine that may be doable and acceptable, on a heavier machine I think you would get a lot of jerking and banging.

On my Chiron I think I have around about 1,000, maybe 1,200, cant remember for sure.

Hood
Re: Servo for lathe spindle ?
« Reply #79 on: October 06, 2014, 04:49:58 PM »
Strange to me is the higher acceleration seems to correct the problem.Before that i had acceleration of 200 only and i could not tune the motor (very unstable)...

Tasbiz