DRIVEN

When trueing comm, do you have to cut all the way across or just the brush contact path?

Speedie

all the way across.

fatdoggy

If you want to decrease the rotating mass as much as possible then yes all the way accross.

Randy Caster

iTrader: (47)

Also, when you are adjusting how deep the cut will be, set the bit so it starts cutting on the part of the comm with no brush contact. It might be good for a newbie to go over the comm with a black sharpie so it is all black, then it will be much easier to see when you are cutting into the comm.

Some people use oil when cutting the comm, but I dont make deep passes and just cut dry, but it is a good idea to lubricate where the armature shaft will make contact with the v blocks.

DRIVEN

The reason I asked because as I turn the wheel from left to right, the wheel gets harder to turn as after the brush contact path as I go from inside out. Am I cutting too deep at one pass? Also after marking the comm with a sharpie, only the slotted part of the comm usually still have sharpie left on it. Is that normal?

fatdoggy

You could be cutting the wrong way. Try cutting from the outside in. The cutting tip on the bit should be the leading edge for each cut. Cut the comm down till there is no black left on the comm. Also do alot of very light cuts instead of a few deep cuts.

Speedie

all of the lathes Ive seen use a one directional cutter. On my Cobra its right to left. You never want to backcut when cutting a comm.

EddieO

iTrader: (6)

If it gets harder as you cut across, that is sometimes a sign that the bit is not aligned correctly and its causing your lathe to cut your comm into a cone shape....the difference won't always be visible to the naked eye. Use a set of digital calipers to measure it at different spots to see.....if the comm varies in areas....thats bad.


Later EddieO

DRIVEN

If looking from the top, my bit is installed like this...

|\
| \

I am cutting from left to right. Is that correct?

jeepnyy

RIGHT ..........lol......

Speedie

What lathe are you using? ANd what way does the arm turn?

The way that bit is pointing it should go right to left.

DRIVEN

I am using the Team Orion lathe, If looking from the top, the arm spins away from the bit.

dsrbltoys

iTrader: (1)

I believe your going in the WRONG direction. The bits flat side should be the cutting side. So right to left is the correct direction.

acutts

Using a Hudy Lathe I am sure cutting from Right to left is correct!

Speedie

Definately right to left is the way to go. Right to left only. Just remember the number on the dial so you can back it off and bring it back to the right.