Comm cut limit??

[twism86]

Hey, im was wondering if there a point were you cant cut your comm and further and need a new motor or armature? thanx for any responses.
-twism

[Grizzbob]

Yes, there is a point where further cutting won't help performance, & going too far can tear up the comm(& possibly the lathe's bit) completely. Now exactly how far is open for debate, but I think common wisdom says that .270" is about the smallest you want your comm to be, although I have cut a few down a bit further than that(but that's really pushing it).... :)

[jeepinator]

When the bit starts cutting into the shaft you have pretty much worn out the motor. I don't recommend going any further than this.

[Rick Hohwart]

.270 - .275 is the smallest you want to go. When the comm is this small you risk it flying apart while the motor is running and even worse flying apart while the comm is being cut which could ruin your expensive diamond bit.