Hey folks, jus got a new Baldor Servo Drive(H2 Inverter). Had break down with previous one(got old). All is well except I'm hearing an occassional down shift in the spindle speed. While cutting through some material , you can hear that down shift come n go in 2 second durations. (Trying to figure if its the actual spindle motor or the axis experiencing some sort of periodic stall). Not that worried but am wondering if its trouble around the corner.

One thing I have now , I didnt have  previous to the new install, is Mach 3 spindle speed adjustment control. Use to have only ON/Off function. Its a nice addition having  real time speed overrides @ my finger tips.
Dont think thats a contributor, just wanted to mention.

Anyway, all my knowledgable compadre's out there! If you have any suggestion's they are more than appreciated.

Thanx-A-Mill.....

Is it just when loaded? could maybe be a parameter needing set in the drive to account for torque and current? Not familiar with the Baldor stuff I am afraid
Hood

Also, are you certain it isn't harmonics coming from the spindle? I have heard this many many times on large industrial machines. It makes no sense to me how a spindle running at 10,000 rpm can emit a sound with peaks and lows in a 2-5 sec. cycles, but it is very familiar.

Brett

Thanx for the suggestions my friends. I will look into those possibilities and get back to you.

again..thanx.....