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Old 01-04-2007, 03:18 PM   #2536
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I have noticed that by using a fan on the endbell it reduces the heat generated considerably. More so than just a plain heat sink on the can. The endbell copper draws immense amounts of heat generated by the brushes onto the comm. I run Epic stock, CO27, and Monster using the fan keeps them much cooler than without. Unfortunately I don't have a tempgun to get exact measurements, but to touch its way cooler. I use a Sunon 7.2v fan.
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Old 01-04-2007, 03:45 PM   #2537
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hi guys just a quick question.

what sort of dyno do you guys use that have them

many thanks
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Old 01-04-2007, 08:11 PM   #2538
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Quote:
Originally Posted by Boosta
I agree with that to a point but think that it's a case of the brushes on the comm generate the heat which is transfered to the can/mags then the temp of the can and mags get to a point that they can't disepate any more heat any quicker (the surface of the can is only able to get rid of a certain amount at any given time) which in turn means more heat builds up at the comm/brushes which in turn results in fade. It's kind of like a tap on a water tank you can open the tap all the way but it will only allow a certain amount of water to flow through it, so if the water tank was being filled (heat building up at the comm/brushes as you race) at a higher rate than the tap can release it, it would eventually over flow (more heat building at the comm/brushes = motor fade).
Hope that made sense
tcs =larger tap on tank ye
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Old 01-04-2007, 08:23 PM   #2539
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Quote:
Originally Posted by MR JOLLY
but then if we can get a good can heat sink this in turn will keep the motor cooler longer & no Motor fade

can/mag get to hot = motor fade
just remember this
there is a Plastic Endbell between the can & brush/comm & i have allways taken measurments from the can & not the arm through the can vents (as this gives you a false reading), so i`ve been told & taught

so if get the can to dissapate more Heat quicker then this in turn will keep the comm/brush cooler ??


Just curious, why does measuring the arm temp through the vent holes give a false reading ?
Thanks.
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Old 01-04-2007, 10:07 PM   #2540
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hey everyone im wondering wat i should use for rollout on my track every time i run my co27 it gets to hot and im running a t2 on foams with a 116 spur and the track is 80 by 35 also wats a good brush and spring combo.
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Old 01-05-2007, 12:15 AM   #2541
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My CO27 run very hot today and stop runing. Is this happen? Or my ESC got bad??
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Old 01-05-2007, 12:52 AM   #2542
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@jagthe arm runs cooler then the can does ,so most heat is in the hoods can/mags part

this dicussion is trying to see which bit is worth cooling more then the other parts IE;Endbell vs can/mags

i still think it`s worth cooling the can/mags is more important then the Endbell (yes Endbell is where the heat starts but it end up at the can/mags which in turn saturates the mags with heat then fades

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co27 gone bad
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Old 01-05-2007, 01:49 AM   #2543
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Quote:
Originally Posted by lignum vitae
tcs =larger tap on tank ye
It did make sense then for sure the tcs would equal larger tap in just the same way a heat sink on the can would or a fan blowing on the can would
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Old 01-05-2007, 02:02 AM   #2544
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Quote:
Originally Posted by MR JOLLY
@jagthe arm runs cooler then the can does ,so most heat is in the hoods can/mags part

this dicussion is trying to see which bit is worth cooling more then the other parts IE;Endbell vs can/mags

i still think it`s worth cooling the can/mags is more important then the Endbell (yes Endbell is where the heat starts but it end up at the can/mags which in turn saturates the mags with heat then fades

@atomapapa
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i'd say can/mags also not because i think the mags getting hot causes the fade but because it's easier to cool the can and more effiecient, i think to get the same amount of cooling on the endbell would need a completly new end bell design with some sort of cooling aspect incorporated into it. I did come across a web page that stated to totally demagnitise a magnet it would take a core temp of around 150c but didn't say at what temp heat would start to have an effect on them ie: at what temp it would start to fade. Ultimately it's simple keep it cool the best you can (no pun intended)
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Old 01-05-2007, 05:08 AM   #2545
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Quote:
Originally Posted by MR JOLLY
@jagthe arm runs cooler then the can does ,so most heat is in the hoods can/mags part

this dicussion is trying to see which bit is worth cooling more then the other parts IE;Endbell vs can/mags

i still think it`s worth cooling the can/mags is more important then the Endbell (yes Endbell is where the heat starts but it end up at the can/mags which in turn saturates the mags with heat then fades

@atomapapa
co27 gone bad

it is the can and magnets causing the fade.the current stock and 19 turn trinity motors have magnets that are heat sensitive.the motors fade when they get hot.if you run a motor and it gets so hot that it fades,it will need to be rezapped to bring the power back.if you notice,a checkpoint 19 turn has mod motor magnets that are much better than the stock and KD 19 magnets.they do not fade with the heat.
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Old 01-05-2007, 05:15 AM   #2546
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got a question about recently dyno'd motors, I used my APS to dyno two stock motors the first was pulling about 6amps, and was running at approx 23,000 rpm and the second was running at about 23,500 rpms. the motors dyno'd were Epic Stock 27t motors. Are these relatively good numbers? all were done at 5v, for 10 seconds...Thanks Jeff
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Old 01-05-2007, 09:48 AM   #2547
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Quote:
Originally Posted by skiv
hi guys just a quick question.

what sort of dyno do you guys use that have them

many thanks
We've got a couple in our shop:

- Our tuning workhorse is the Competition Electronics Turbo Dyno. This is a stand-alone slave-motor dyno that tends to be pretty accurate and consistent. It has historically the staple for motor tuners, but they are not being manufactured anymore, and the prices on the used ones are starting to skyrocket a bit.

- For the nice graphical dyno plots that go in our packaging, we use a heavily modified Fantom Dyno (custom hardware and software). These are flywheel dynos that connect to a PC. This dyno has been kicked around historically as not being one of the most accurate measures of performance, but it actually has a few things going for it: 1) You can still buy it for a reasonable price 2) It does put a load on the motor and measure way more accurately than a free-wheeling motor tester 3) If you use it to measure relative changes while experimenting, it's actually pretty useful.

The other big one was the Robitronic flywheel dyno - it is the best of both worlds to a certain degree. The included software is a lot more versatile than the Fantom dyno, and the accuracy and quality is very good. They are also gettting harder to find.
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Old 01-05-2007, 09:53 AM   #2548
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Quote:
Originally Posted by MR JOLLY
@jagthe arm runs cooler then the can does ,so most heat is in the hoods can/mags part

this dicussion is trying to see which bit is worth cooling more then the other parts IE;Endbell vs can/mags

i still think it`s worth cooling the can/mags is more important then the Endbell (yes Endbell is where the heat starts but it end up at the can/mags which in turn saturates the mags with heat then fades

@atomapapa
co27 gone bad

Hmmmmm. Should be possible to test quantitatively...... we could do something like this:

1) Baseline Dyno Run
2) Cool off Motor Can / 5 minute 2-4v pulsing break-in / Dyno Run
3) Endbell Fan / 5 minute 2-4v pulsing break-in / Dyno Run

The idea being that in #2, the can should be experiencing the benefit of being cooled, and in #3 it would be endbell only.

I can run the experiment in a day or two.... got to get ready for racing. Anything else you guys want measured?
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Old 01-05-2007, 10:31 AM   #2549
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jeff,

I too have an aps dyno.
5 volts pullling
6 amps @ 23,000 rpms is probably a good place to start.

fistI do an out of the box dyno run, if it is good I leave it alone.
If the numbers are low, I returned them to the break in mode. at between 1 and 3 volts for 30 minutes. clean the com/brushes cool down the moter and take another pull. continue this until you are pulling at a minimum 8 amps, take rpm reading to help you adjust your gearing on each particular motor.

for very low motors, you may have to do a complete blue print rebuild. cut com, align hood, center the arm, new brushes and springs and completely clean motor.

The highest numbers I have been able to get with my rebuilt cobalts are 6 to 8 amps @ approx. 25,000 plus rpms. with new monster and xx motors, 10 to 11 amps at 27,000 plus or minus rpms

according to some tuners 6 amp draw is good, the reasoning is the higher the amp draw of the motor, the hotter it will run. they detune them by filing down the brush leading and trailing edges.

My 6 amp cobalts are plenty fast when geared in the all allusive sweat spot.
I have yet to run the monster nor the xx motors.

I found that the cobalt likes to rev but they are torgue motors. I usually go up a tooth. maybe it's a p2k2 in a blue can? later
Wayne

Last edited by nagatahawk; 01-05-2007 at 10:42 AM.
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Old 01-05-2007, 11:26 AM   #2550
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Default co27

so I just picked up a couple of these co27 motors. and I was just wondering what spring/brush combo people are using?
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