View Full Version : Servo 150 problems?

02-12-2012, 05:17 PM
Got a Servo 150 power feed on a mill at work.It came in not working,upon tearing it down and inspecting it the problem appeared as a burnt control board.Two caps,three diodes and one resistor all toast.Running the motor on another supply proved it to be functioning normally.

So I ordered a new board from Cal-Metrics(good people BTW) installed it and test ran it on the bench.Seemed to work fine.On the mill in use however it behaves oddly.

The most obvious fault is that upon being dropped in gear either direction it doesn't respond until the speed pot is cranked up maybe 1/3 of it's range.Every other Servo feed I have used responded from maybe 1/20th of it's range.When it does begin to move it will lurch to what should be the 1/3 setting,quite a suprise the first time I used it.

I'm wondering now if maybe the speed pot is fried too or if something else is wrong.Any clues to look for?

02-12-2012, 06:23 PM
Probably a bad speed pot.

02-12-2012, 07:01 PM
Same here bad speed pot.

02-12-2012, 08:21 PM
Easy to check the pot in circuit, measure the DC voltage between the slider and 0v (common).
If it shows no voltage until 1/3 rotation then it is the pot, if it shows gradual increase then the pot looks OK, and it could be a min speed setting etc.