I finally got my Yaskawa motor and amp to work with the Bob Campbell break-out board using the Pixie card to switch from step and dir to +/-10v.  The Pixie works great.  The basic problem was that during tuning I had to turn the K parameters to very low values (Kp=2, Kd=13, Ki-0).   The speed reference mode works fine so the Yaskawa amp does not need to be set up in torque mode.  What a relief!

Keith Clark

nice, good to hear the pixies work welll, I might be having to get some soon.
Hood

Keith,
When are we going to see a video of the lathe up and running

Keep up the good work!

Thank
Brian

Brian,

If I really am out of my quagmire and can finally move forward, I am hoping to be filling the air with sawdust within a month.  I have to go to Amman, Jordan to give some lectures next week so I will lose a week.  Darn, my day job gets in the way!

Thanks Brian, I really appreciate you!

Keith

Hello,
Can someone give me some details on what a "pixie" is and how I can get one.
I have a Matsuura that has Yaskawa servo amps and I want to drive it with mach 3 and a breakout board.
Thanks for all your help.

Pixies are boards that sit between the computer and analogue drives. They convert the Step/Dir signal from the PC into an analogue +-10v for the drive. you will find info at www.skyko.com
 I am about to use the CPU board from my Tek10 drives to do the same thing, I am not sure if CNCTeknix sell the CPU boards seperate and if they do how much they are but might be worth emailing them to find out, there web is www.cncteknix.com

Hood

Thanks,
I am familiar with stepper motors but my knowledge in servos is limited.
Can you explain how a servo drive works?
From reading the pixe datasheet, it looks like it wants a encoder input and the PID control lives in the pixe.
Does the servo drive only control the speed of the motors?
From looking at the yaskawa manual it has a tachometer input to the servo drive, So is the speed control closed loop also?
Also the speed reference input is 0 to +-6 for the yaskawa servopack, the output is jumper selectable on the pixe to -10 to 10 and -5 to 5, Are the voltages adjustable between these ranges?
Sorry for the million question.
Thanks for your help.

I dont know a great deal about servos and servo drives as I am in the process of using them for the first time. I do know how to blow up drives in a split second though
 I think most analogue drives use a tacho to read the speed they are moving the motors at and it is the control that needs the encoder (or resolver) feedback. The drives I have however need an encoder input and as far as I can tell dont have any input from a tacho, I am not sure but I think the encoder feedback to my drives may be needed for commutation of the AC motors but until I can find a manual I dont know for sure. The encoders signals to my drive pass through and would originally have gone to the control but now it will be the Tek10's that will use this to close the loop as far as out of position errors are concerned.

I dont know if the pixies can vary the voltage between the ranges you mention but I know the Tek10's can so I would assume the pixies to be the same.

Hope this all makes sense to you but as I am new to servos its hard for me to give precise and definitive answers.

Hood

Thanks man,
You are very helpful

How does a servo drive that is 2 wire know what direction and speed?
I have been reading the yaskawa manual and the speed input terminals description says:
2. is at SG 0V. The rated forward ratation is given at +/- 6V.

Does this mean that 0V to -6V is 0-100% speed one direction and 0V to +6V is 0-100% speed the other direction?
I would just hook it up and play with it but I really dont want to let the smoke out of the boards on my new mill.
Thanks