ok i am starting over give me tips!

[mavrick0611]

ok i just bought a new motor i should have it by saturday. incase you didnt see my other thread i have severe problems cutting my comm. then my armature wouldnt move. this may be like beating several dead horses :D :D but give me good instruction on how to do this. i thought i had it down pat then my armature screwed up.

thank you,
aj

[HowieStern]

take a good look at the new armature you get....

what you want to get when you cut an old comm, is to make it look exactly like your new one....

you want to take off as little copper as possible when doing this... this means making as few passes over your comm as possible... so make a series of light cuts... when your comm looks like a new one... you are done...

we can describe how to do this all day over the net, and you may still not get it... you need to learn how do it a bit on your own... so don't be afraid to practice on your old comms...

peace out... :)

[JP]

I used to cut slot car armatures which are way smaller, so im not completely blind on this subject. We made 3 passes with them. Once the lathe got running, we put a permi. marker on the comm and let itself cover in black. I made VERY light passes, just barely enough to take the marker off. I then recoat it the second time with marker and do it again, for 3 times. Remember, start at the very end and slowly drag it across the comm.then recoat it in marker for your next pass. If its not thin, well, it already happened to you before, and you now know what to expect. Also, dont play with the controls to deepen it while your cutting. It may sound stupid, but if you even touch it, there is a chance that it will dig deeper.

[XXXER]

From what i understand, you can take actual chunks off of the comm(correct me if i am wrong guys), plus, i think it is hard on your bit, and also, are you using cutting fluid? You do need to use that, again, that is from what i understand.

[Leet TC3]

Do not ever use the ink method more than once. Why should you need that? The purpose is to shave as little off the comm as possible. If you ink more than once, you will NOT be truing your comm, you will ONLY be making it smaller.

If after the first pass there is still ink on the comm (usually where the brushes make contact), move the bit to the far end, move it in a VERY small amount, apply a little bushing/bearing oil on the comm, and make another cut. Keep doing this until there is no ink showing.

[ 06-19-2001: Message edited by: Leet TC3 ]

[mavrick0611]

ok after the first pass and you move the bit in slowly, do you just cut the black spot or the whole comm? i htink that may be where i messed up.
aj

[HowieStern]

you don't want to take a bunch off because this will give you less material to work with the next time ... basically, you want to be able to true your comm as many times as possible... if you only get one turn out of an armature, you might as well pitch your lathe and just buy new armatures every time your comm gets messed up....

every time you reset the depth on your bit, you need to go over the entire surface of the comm... never just true the middle..... the purpose of a lathe is to get a super smooth and perfectly round surface the entire length of the comm....

peace out.... :)

[Leet TC3]

Always true the entire comm, not just the "black spots". Download and watch that video. ;)

This could very well be what you did wrong the first time. the "black spots" is where the comm is a little thin when compared to the rest of the comm. If you just lathe the black spots, you are making the situation worse, not better. What you want to do is true the ENTIRE comm until all the ink is gone, thereby making the ends and the middle of the comm equal thickness.

Remember to add oil to the comm after that first pass...

[VexVegaz]

here check this out
http://www.veytrex.com/cutcomm200.rm

its a small video showing how to cut comms
u will need real player to view it though.

[mavrick0611]

k, i have a question. What happens if you take to much off of the comm?
aj