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-   -   Cutting the comm? (https://www.rctech.net/forum/radio-electronics/236138-cutting-comm.html)

Chris__RC 08-07-2008 05:59 PM

Cutting the comm?
 
I have a P2K2 27t motor in which I race stock and a Novak gtx esc. It has no brushed limit but it doesnt do brushless. So brushless is out of the picture now. I have about 25 runs on my motor and I just got 2 sets of new brushes. I was wondering since I will be racing should I get the comm cut now or wait until say 40-50 runs? What will happen if I dont cut my comm? I have a couple motors being shipped to me, a Checkpoint 19t with 2 sets of brushes, Orion Element 19t 2007 version, Peak 13X5 and a 12X5 armature. But my LHS charges $10 for the 1st time he cuts it and $30 every other time!!!!! The motors I got have their comm just cut but I dont know how long I could go without cutting the comm.

And is there is "poor mans" method for breaking in brushes? My Duratrax Onyx 230 doesnt do motor break in.

Brandon A 08-07-2008 08:29 PM

I'd recommend cutting that comm now. It makes a huge difference in performance, especially when racing. If you don't cut your comms frequently enough they will cause your motor to overheat and may damage the motor.
Oh yeah and $30 dollars is insane for a comm cut. My lhs charges $3.00.

Bigshades 08-07-2008 08:55 PM

30 dollars is madness for a comm cut! Dont let them rip you off!

I purchased a used comm lathe for 30, a very good deal. With everyone moving to BL, you can pick up lathe's for cheap.

Chris__RC 08-07-2008 09:00 PM


Originally Posted by Brandon A (Post 4718811)
I'd recommend cutting that comm now. It makes a huge difference in performance, especially when racing. If you don't cut your comms frequently enough they will cause your motor to overheat and may damage the motor.
Oh yeah and $30 dollars is insane for a comm cut. My lhs charges $3.00.

Ya I know!!! I am getting 4 motors and a extra armature and I hope he will give me a deal on cutting them. Like $20 for everything.



Originally Posted by Bigshades (Post 4718876)
30 dollars is madness for a comm cut! Dont let them rip you off!

I purchased a used comm lathe for 30, a very good deal. With everyone moving to BL, you can pick up lathe's for cheap.

But I dont have a power supply.

I heard of comm sticks. Do they work good and is there anything else that I will need when I maintain my motor? I already have bushing oil.

I am thinking of using the bearings in a Peak 13X5 I am gonna get a put them on my p2k2 motor. How much of a difference will that make?

Chris__RC 08-07-2008 09:21 PM

I am looking for a website that carries all of Losi parts, RPM shock body wrench, RPM wheel and shock nut wrench, and a comm stick. DO you know of any? Horizon has everything but they are a little overpriced and only have a comm pen and Losipartshouse.com is underpriced but I dont think they have a comm stick and a main doesnt carry RPM. So any ideas?

Bigshades 08-07-2008 09:35 PM

You dont need a PS for a lathe, just a 3-4 cell battery.

Nothing will benifit a motor like a True comm lathe. Period. A comm stick wont do.

Chris__RC 08-07-2008 10:21 PM


Originally Posted by Bigshades (Post 4719008)
You dont need a PS for a lathe, just a 3-4 cell battery.

Nothing will benifit a motor like a True comm lathe. Period. A comm stick wont do.

I have a old Integy 1400 nicad battery pack that I never cycled. I could dissemble it and make it into a 4 cell pack. Will that do? I have a offer where I get a stock comm lathe for $30 shipped with a diadmond bit and all you have to do to cut it is take the brushes out. Does that sound like a good deal?

Castradamus 08-07-2008 10:24 PM

You should invest in a comm lathe. You can probably pick one up for cheap in the forsale section. I have a nice DC charger that will let you break in motors. APS Dyno/Charger S3.

See my signature and PM me if you are interested.

mauromj 08-07-2008 10:24 PM

I have a lathe I could give you a really good deal on, like cheap. Pm me.

Bigshades 08-08-2008 07:59 AM


Originally Posted by Chris__RC (Post 4719150)
I have a old Integy 1400 nicad battery pack that I never cycled. I could dissemble it and make it into a 4 cell pack. Will that do? I have a offer where I get a stock comm lathe for $30 shipped with a diadmond bit and all you have to do to cut it is take the brushes out. Does that sound like a good deal?

Yeah, that would work.

And a lathe for $30 with a diamond tip is a great deal. Go for it! :D

Chris__RC 08-08-2008 09:32 AM

Is there a way where you can like destroy a comm by doing it wrong or something?

Brandon A 08-08-2008 09:39 AM

Yes, if you dont mount the armature on the lathe properly and the bit is not flat against the comm you could gouge it so be careful. Also you only want to take a little material off with each cut so you dont damage it.

Chris__RC 08-08-2008 10:43 AM

Is there like a how to video on this?

JeromeK99 08-08-2008 03:15 PM

$30?!?!! and $10 each time after?!! Holy ripoff :batman:

I don't know the crowd too well at OCRC.. but at our track we're all pretty friendly and there is always somebody that would cut your motor for free if you don't have a lathe.. especially for the new folks.

Get the lathe if you plan on running brushed! To be competitive, I usually cut my motor at least every 4-6 runs or before the races start. Mostly what this does is gets all the brush residue off the comm and makes a cleaner contact point. If you are waiting 40-50 runs.. you got one slowwww motor guaranteed! That many runs and your comm is going to need several passes on the lathe to get it level again..

Brushed motors have to be maintained. Regular cleaning... I'd say at least once per track session... bushing oil at least once per track session... Brushes chip as well.. so you need to get a "hard" comm stick to take the sharp edges off and clean any crud left on the contact point.

You can definitely ruin your comm if you goof up with the lathe!

Cutting your motor won't make the motor last longer.. it just makes it perform like new during it's lifetime. I race just about every weekend (with a few practice runs as well) and I can get about 4+ months of out of brushed stock motor.

Good luck!

Jerome :tire::tire:

Chris__RC 08-08-2008 04:01 PM


Originally Posted by JeromeK99 (Post 4721244)
$30?!?!! and $10 each time after?!! Holy ripoff :batman:

I don't know the crowd too well at OCRC.. but at our track we're all pretty friendly and there is always somebody that would cut your motor for free if you don't have a lathe.. especially for the new folks.

Get the lathe if you plan on running brushed! To be competitive, I usually cut my motor at least every 4-6 runs or before the races start. Mostly what this does is gets all the brush residue off the comm and makes a cleaner contact point. If you are waiting 40-50 runs.. you got one slowwww motor guaranteed! That many runs and your comm is going to need several passes on the lathe to get it level again..

Brushed motors have to be maintained. Regular cleaning... I'd say at least once per track session... bushing oil at least once per track session... Brushes chip as well.. so you need to get a "hard" comm stick to take the sharp edges off and clean any crud left on the contact point.

You can definitely ruin your comm if you goof up with the lathe!

Cutting your motor won't make the motor last longer.. it just makes it perform like new during it's lifetime. I race just about every weekend (with a few practice runs as well) and I can get about 4+ months of out of brushed stock motor.

Good luck!

Jerome :tire::tire:

Briguy is selling me a Cobra Pro com lathe with Diamond bit and a couple extra comm's to practice with all for $30 SHIPPED. I am gonna make an order off Tower. I am gonna get 2 Trinity bearings (dont tell anyone :sweat:) Cobra comm cutting fluid, Trinity Comm pen, Trinity Formula 2000 comm drops, and Trinity Royal bearing oil. Is there anything else I need and what is the difference between the comm cutting fluid and the comm oil?


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