I have read the post below on spindle control and I am confused as to how this is supposed to work.  I have a 2280 card, Mach R3.042.029, and Galil plug-in 4.4.0.0.  I am using a Yaskawa VFD for the spindle. It is a vector drive, but I am currently just using it in 'dumb' mode. If I recall, I can either run this -10V to 10V or 0 to 10V and use the forward/reverse inputs on the VFD for direction.  The machine is already wired for the second case, so it would be my first choice.

I will limit the drive to 120Hz and would like to configure it so that 120Hz = a 10V input.  The machine currently has step pulleys, so I would need to use the pulley ratios to calculate the correct motor speed.  As an example, lets say I'm using a 2:1 speed up drive and command an S5400.  This would be 2700 rpm at the motor (90Hz) and voltage out should be 7.5V (10*90/120).  Any way to do this?

If I can't do it with the above hardware, can I do it if I add a spindle encoder?

Thanks,
Mike
  

Mike,

Theoretically, you would set up your pulley ratios in Mach and use the spindle axis in the Galil plugin to output +-10v to control both speed and direction.  But...  I have not tested this at all.  My spindle uses and encoder and it is not using pulleys (motor speed == spindle speed), so that's a pretty simple setup.  Until I can mock up a VFD spindle, I can't say how the plugin will react.  But the code is meant to do as I described.  It's just not proven out.

Steve

Steve,

Thanks for the help.  I don't know what I was doing the other night, but the voltage was dropping with increased rpm.  I checked it tonight and it seems to be working okay. Pulley ratio does not have an effect, but that shouldn't matter because the signal is proportional to the max voltage.  In my example, a max rpm of 7200 on the pulley config will output the correct 7.5V at for an S5400 command.

There are a couple of limitations.  First of all, it appears that the minimum signal is 1V, so you can't go less than 10% of your max speed.  Secondly, commanding the maximum speed causes an error on the Galil.  If you want a 5000 rpm top speed, enter 5001 in the configuration.

Right now, I am just bench testing.  I have a new lathe with a Dynapath Delta 50 that I am working on now, so the mill conversion will have to wait a few weeks.

Mike