[Jkurtis]

Hi- I am trying to use a Yaskawa ServoPack (SGDH-08) with an SGMAH-08 as a spindle motor for my "5Bears.com" style bench top mill. The spindle motor will drive a Sauter HSK40C live tool holder used as my spindle.

I have successfully used these servopack/motor combinations for the X,Y,Z (at the 400W size).

I am struggling to get this to operate properly as my spindle.
I am using a USB smooth stepper for the pulse train.

In the SS plug in (latest version, 17e I think), I have enabled Step/Dir for the spindle with 4uS pulses.
In Mach3, I have enabled the spindle with Step/Dir (again 4uS pulses).
In Mach3, under motor tuning, I set steps per at 8192 (2048 line encoder *4), the velocity at 3000 (though the Mach manual says this should be revs per second (thus 50), this did not work for me.

I can move spindle in both directions without difficulty.

My problem is the speed is not what I expected. When I issue an S60 command (i.e., 60 rev per min), I get 72 rev per minute. I do not yet have a Tachometer to check higher speeds (ordered last night for 13 bucks from Amazon...). I could easily play with the steps-per setting, but I am surprised this did not work more accurately.... The increased speed occurs in both directions. I have checked and the electronic gearing on the servo pack is off.

Any ideas ???

thx
jake

[LeeWay]

There are probably some settings in the servo drive that can be adjusted to get closer to desired speed.
My mill is a Novakon Pulsar and it comes equipped with a Servo Spindle. It also has a belt on it. The motor actually runs at 3000 RPM and I get 4500 at the spindle. At all the ranges I checked after adjusting the drive, I have it within 1 RPM over or under at 4500 RPM and gets better the lower it goes.
That is not bad. You will need to source a manual if you don't have one. You will need a tach too. It takes a little trial and error, but well worth the effort.