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Old 10-09-2003, 10:25 PM   #1
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Default motor tunning...

can anyone help me or give me any advice on motor tuning...i have some p2k2's and GM3 motors...and they're really in bad shape...tried to run off-road and won't give me any punch/torque/power...here's how i re-build my motor..

tear it down...
clean the can, end bell, brush hoods and bushings...
cut the comm..
replace brushes....
break in brushes for 10 min at 3 volts...
cut comm very lightly after break in....
commm drop on comm and at the back of each brush...

here are the spring and brush i use...
red spring on positive...
green on negative...
trinity 4499 e brushes...

after this the motor still isn't giving me any power...

help pls...
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Old 10-09-2003, 10:34 PM   #2
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10 minutes is a bit overkill on the brush breakin.. usually 5 minutes will do... Just make sure they are seated.. and then you are done.

How old are the motors? Weak magnets will make the motor week no matter what you do.

You left one step out when tuning your motors... "aligning your brush hoods". This is the SINGLE biggest improvment you can make to a motor's performance.

The other possibility might be that your cells arent' performing up to par... check those as well. All the other things on your list seem ok.. make sure that the drops you are using are OK for bushings... otherwise use bushing oil.
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Old 10-09-2003, 10:51 PM   #3
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I agree, 10 min is WAY too much for break in. Your wearing out your fresh com before you even go out to run. Heres what I do for break in:

1) Do the normal stuff (clean it, new brushes, skim com)

2) I use my pulsar and run it at 3 volts untill I get a fairly solid amp draw. It should sound funny and the rpms jump up and down when you have unseated brushes, so mainly just listen and look to see if it's arching bad. It should have a nice smooth consistant sound.

3) I will then just pump it up to 4 volts for a few seconds and listen and watch again. If the Rpms fluctuate then they aren't seated all the way. Just bring it back down to 3 volts again and run it for 1-2 more min.

4) Make sure you have the brush hoods aligned, have fresh brushes/springs, strong magnets, and properly broken in bushings. With that you should be ready to go. My total break in procedure takes about 3 min total. 4 at the most, but I use super stiff brush springs and high silver brushes so taylor it to your needs.

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Old 10-10-2003, 12:30 AM   #4
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All check brush hood alignment on EPIC copper hoods when you rebuild motor. Because copper is soft . You do know how to align hoods ?
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Old 10-10-2003, 03:39 AM   #5
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does polishing bushings make a big difference in a stock motor ? I would think so cause you'l have less drag on the armiture. What do you guys think ?
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Old 10-10-2003, 05:14 AM   #6
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Los1Fan - Is your car geared correctely?(most likely) Also, do you take care of your cells? It could be that your batt's a either old or mistreated and need to be replaced.

As everybody has said, 10 mins is way to long, I usually do 4 to 5 and extend if there not fully broken in. If you make a cut after break-in you'll need to run the motor in for another 30 secs after the slight cut so your brushes re-seat properly.


Also next time forget the comm drops and see if it makes a difference, when I used to run trinity drops they didn't do anything but make a mess and cause drag(hence now I don't use comm drops).

Align the brushes, cut a pair of brushes square and put then in and run for a few secs and see if there wearing in the middle, if not, you need to move the hoods slighly/as needed so they wear perfectely in the middle. Motors run much smoother if the brushes are aligned. You may have to slighly elongate (sp?) the holes that hold the hoods down.
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Old 10-10-2003, 05:23 AM   #7
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Fatdoggy, with the comm drops, today i had my motor tested on a friends dyno, and with the Tribo comm drops in, it gave it an extra 2000+ rpm and boosted everything else up too.

I also like to polish my bushings, inside and out, aswell as the shafts. I also use teflon shims on the bushing side from advice from a very knowledable racer.
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Old 10-10-2003, 09:03 AM   #8
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i do the same.
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Old 10-10-2003, 09:58 AM   #9
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Default motor tunning...

Guys;

I have found that all of the EPIC based Stock Motors work best with high Silver content Brushes (Putnam's).

Red/Green Springs for a Torque based Motor and Red/Red Springs for a Rpm based Motor.

As for using Tribo Com drops, my experience has shown a power LOSS on the Dyno (Robitronic).
On the Track, they seem to help a little if it's getting close to the time for a Rebuild, but the Brushes always end up being severely pitted afterwards. For this reason, I use the Tribo for Bushing lube instead.

A few of the EPIC Motors that I've seen recently have had Oversize Hoods, where the Brushes a very sloppy inside. This makes it very difficult to maintain a decent Brush alignment.
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Old 10-10-2003, 10:21 AM   #10
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POPS: I agree on Tribo. Works wonders on bushings, but hurts performance when placed on brushes or comm.
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Old 10-10-2003, 10:24 AM   #11
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Here is an article with pictures that shows how to tune a stock motor:
http://www.motortuningsecrets.com/tunestockmotor.html
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Old 10-10-2003, 01:33 PM   #12
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wow...i post the same question in trinity and the ratio is 10 to nuthing anyways...magnets are fine...hoods aligned (i can tell by how the brushes looks liike after breaking in, very evenly worn from corners to corners)...bushings i do polish and clean...i already tried running w/o the comm drops...batteries are good and fresh..fukuyama batteries....i run on-road mod touring so i know the cells are good...as for the magnets...is there any way to check?...i don't have a magnet zapper or anything...and neither does my lhs...and thnx for the response guys...i guess every one has their own way of motor tunning...

shiloh : thats where i get most of my ideas on tunning...and they do help a lot...
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Old 10-10-2003, 01:36 PM   #13
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The only thing left to do is get another stock motor that you know is working perfectly, and toss it in your car with the same ESC, batts, etc... if that motor runs strong as heck, it may just be time to toss that motor in the trash If the other motor is ALSO Weak in your car, the problem is somewhere else.
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Old 10-10-2003, 01:42 PM   #14
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did that done that.. ...i'm running out of ideas man...
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Old 10-10-2003, 01:50 PM   #15
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dude if you cut the motor why are you recutting it after breakin. once is enough .
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