Sherline Speed Control kaput

[mikkojay]

Hi,
I was wondering if anyone has ever had to replace a component on a Sherline speed control. Mine just kinda "quit" without any spectacular failure. I tested the motor straight to 115 v and it ran fine, so the power, switch, and motor itself are fine. I just thought I would ask before going thru the motions of testing all the components on the board.
Thanks, Mike

[mikkojay]

Sherline Shmerline!
I ended up seeing a 15 amp router speed control (item 43060) on sale
at www.harborfreight.com for $9.99!
I have a feeling the triac is fried in mine. For 10 bucks, I don't care what is fried on it- the fact that it pooped out tells me that it is quite possibly an insufficient design anyway. If I replace a bad component in it, I don't want to worry about it going bad again. I can take the old one off the motor, which will be less junk that has to ride up and down on my z-axis! Ok, I've convinced myself I'm not too lazy to figure out what the actual problem was...
-Mike

[H500]

The mosfets on my mini lathe burnt out twice. I ended up using a better heat sink and a faster diode. No more problem since.

The harborfreight speed controller might not do a good job of maintaining speed when the motor is loaded. The built in controller is usually optimized for the motor.