Hello Guest it is September 18, 2019, 08:55:18 AM

Author Topic: Servo for lathe spindle ?  (Read 18186 times)

0 Members and 1 Guest are viewing this topic.

Re: Servo for lathe spindle ?
« Reply #50 on: October 03, 2014, 11:22:57 AM »
 Dan: DAC offset is very very delicate.I have to adjust to0.0..something....
Let's hope Hood is going to help on that..
One more quetion:do you know if there are issues if i run mach3 under windows 8.1 64 bit?
Tasbiz

Offline Hood

*
  •  25,849 25,849
  • Carnoustie, Scotland
    • View Profile
Re: Servo for lathe spindle ?
« Reply #51 on: October 03, 2014, 12:42:39 PM »
Good you got the drive sorted :)

Are you entering values into the DAC box? If you are you should not do that, you just press the button at the side and it gets automatically set.

If you have been pressing the button and are still getting the issue then I wonder if you possibly have some noise on the encoder output wires from the drive, have you got twisted pairs for them?

Regarding W8, never used it but the CS-Lab site seems to suggest it should be fine.

Hood
Re: Servo for lathe spindle ?
« Reply #52 on: October 03, 2014, 02:43:21 PM »
Hi Hood,
no the wires are twisted but not properly done yet because i was looking all around for the problem.But is noise a reason for having the motor moving?
Perhaps is a wiring problem.When i program the servo for torque mode i don't get this (but i cannot set tune the motors).When i program it for Speed mode i get it.The problem is in Delta's instructions example it shows V-ref AND T-ref connected either for speed mode or for torque mode with 2 different +- 10V signals.Is that correct?I am totally confused about this.
Also should i connect Com+  of the drive with the encoder? CS lab suggests that somewhere...
Please since you are very experienced with Analog CSMIO help me on those matters..
If you have a simple drawing of the very basic connections between CS and drive (encoders and limits i have connected already and are working fine)...

Thank you in advance,
Tasbiz

Offline Hood

*
  •  25,849 25,849
  • Carnoustie, Scotland
    • View Profile
Re: Servo for lathe spindle ?
« Reply #53 on: October 03, 2014, 03:41:28 PM »
If there is noise on the encoder inputs then there may be the potential for the IP-A to think the axis is moving  and apply a voltage to move it in the opposite direction so as to make it stand still, so noise could possibly be an issue.

You say you can jog fine, is that from within the tuning page?
Have you got a massive error amount set? and when you jog does it constantly increase? Or is it relatively steady?

Did you press the DAC button or enter the value manually?

Not sure what you mean by Com+ but the way I have my encoder signals connected to CSMIO are with the A/A- B/B- I/I- signals connected, I also have the 0V from the encoder output of my drives connected to the Gnd for that encoder input on the CSMIO. I do NOT have the 5v connected as I do not need to power the encoder.

Does the drives manual not show how its I/O are connected? If you are not sure post a screengrab and I can take a look.

Hood
Re: Servo for lathe spindle ?
« Reply #54 on: October 03, 2014, 04:30:58 PM »
 Yes I can jog fine from the tuning page.Now i am at a point where finally the tuning screen works ok in csmio.It is very smooth and nice.But...
If i try to jog from Mach3 screen(after the tuning) the the motor is getting to full speed until it hits on the limit button... :-[.It appears that is getting a lot of acceleration very very fast(no time to hit e-stop button)
I am attaching 2 screenshots.In 1 you can see that the GND is connected to Com+ (nr 11) and this goes to 24V-.
In the other you can see the 2 different +-10v connections to the V-ref and T-ref respectively.
Please have a look and tell me what you think...

Tasbiz
Re: Servo for lathe spindle ?
« Reply #55 on: October 03, 2014, 04:33:46 PM »
 Why do you connect the 0v from encoder to ground of csmio?
Re: Servo for lathe spindle ?
« Reply #56 on: October 03, 2014, 04:37:31 PM »
Sorry i forgot.
I have set a massive error amount set...
Re: Servo for lathe spindle ?
« Reply #57 on: October 03, 2014, 04:48:01 PM »
additionally:
when i jog from mach from the keyboard with slowjog rate up to 30% it jogs ok if i jog more than 40% it is moving really fast and hits the limits.
if i have it on 30 or 20% and try to press shift and jog it is very fast agai and hits the limits...
Now i know why they say that servo tuning is very hard...

Tasbiz

Offline Hood

*
  •  25,849 25,849
  • Carnoustie, Scotland
    • View Profile
Re: Servo for lathe spindle ?
« Reply #58 on: October 03, 2014, 05:48:46 PM »
Ok what do you have set for the max RPM in your servo drive?
What do you have set for the max Velocity in Motor Tuning in Mach?
Do you have any reduction between motor and screw?
What is the pitch of the screw.


Where have you got the +/-10v output wires connected on the Drive?

Regarding your pics above, it looks like your drives inputs are sourcing only, that is a bit of a pain as the outputs from the CSMIO are also sourcing. That means you would need to use something like a relay if you are wanting to connect outputs from the CSMIO to Inputs on the drive.
You may be able to select to have the drives inputs as Sinking but from the above pic it does not look like it.

Hood

 
Re: Servo for lathe spindle ?
« Reply #59 on: October 03, 2014, 10:28:23 PM »
Max RPM on drive is by default 3000RPM (i haven't set it but is programmable)
Max velocity in Mach:(i started with low value 200RPM and then increased to 500 and 1000.After every change i redid the tuning)
I have a 0.8 reduction (i go from 24 to teeth on the servo to 30 tooth in ballscrews).My ballscrews are 16mm diameter 5mm pitch.
The +- 10V wires that go to the drive i get from +- analogue i/o outputs of CSMIO.
Sourcing vs sinking ? (sorry i don't know what that means-but i will search on the internet)

Tasbiz