OWWWW!!!!! HOTTTTTTTTT!!!!!!!!!

[greg_in_michigan]

I have a Novak Dually ESC, a Trinity Topaz 11t triple motor, and a Trinity 2400mah battery pack. It's geared 17/84 with Pro-line Road Hawg 2 tires.

I have run the Dually and Topaz probly 7-8 times. They are both new. The Dually has never been run with another motor, and the Topaz has never been run with a different speedo. The Trinity pack is about a year old, and I think is getting a little bit of cell memory.

When I put a few packs through it for the first time in about a month this week, the battery and the motor were extremely hot. I ran it like that 2 times, and both time it was hot as hell. So I then cut 44 1/4" holes in the bottom of the chassis to cool my battery, and that worked great. I can now touch the battery with no problem. But the motor is still way hot. On that run (which was my last run by the way) the motor wire came off because I had a crappy soldering job. And I got through about 3/4 of the pack. The motor was hot, and the batteries were touchable, and the ESC (to my surprise) felt as if it had never been run at all. The heatsinks were cool a could be.

I brought it inside, and I took the motor apart, and when I took the brushes out, they were half the normal size. So I thought the timing was off, because I did this with my Garnet motor. But then I looked inside the hoods, and the rest of the brushes were in there! BOTH brushes were broken right in half. I'm not sure if that is the cause of my motor heat problems, or if that is an effect from the heat problems? If this was the case, how would my bettery heat be attributed to this?

I went to the Traxxas board, and let's just say the replies I got were far less than adequate. I got some people saying that I need to gear !!DOWN!! by putting a gearing of 20/84 or 19/84, and some people saying it's in the tranny, and one guy saying something I didn't even understand.

I think my timing may be off. I don't think I marked where 0 degree timing was on the can, and I took the motor apart, and I don't have a timing guage. So if there a way to put it at 0 timing without a timing guage? I think I am going to go to the LHS in a few days, so whatever I should get or do, I will need to know ASAP.

[greg_in_michigan]

I forgot to mention that I am going to buy a heat sink for my motor. There are 3 different ones I was looking at.

http://www.gpmd.com/images/ascc3928.JPG This is the AE long heat sink for the TC3. I like this one because it's cheap, and it had large fins. I don't think it will fit unless I cut some of the plastic out around the motor. But that won't be a problem.

http://www.gpmd.com/images/tric5652.JPG This is the Trinity large motor heat sink, and it looks like this one will fit without any modification. It doesn't look like it has very many fins though.

http://www.gpmd.com/images/ascc3927.JPG This one is the AE short heat sink, and this one also looks like it will fit with no modification, and it has alot of fins.

Anyone use any of these heat sinks?

[Jason C]

I have the short AE heat sink on my Green Machine3 in my TC3. It works nicely and speeds up cooling a lot more when I aim a small fan at the motor between runs. I think Holeshot also makes heatsinks and you can find them on Towerhobbies' website.

As for timing, if I recall correctly, timing is at (or near) zero when the brushes are centered over the magnets. Turning the endbell counterclockwise will advance timing and vice versa.

[Serius Black]

The replies you got from the Traxxas board were probably dead on.
First of all, you didn't metion which car you're running. Which Traxxas? If it's a Stampede or Rustler, those gearing suggestions are probably valid.
An 11 turn motor is a fairly hot (i.e., fast)motor, especially for bashing around the yard. If you run the stock pinion, it's going to overheat. You need to gear down.
Do you run the battery until the car is running at a crawl? If so, don't! Run the car until you notice it slowing down. Finish the pack off on a discharger.
Other than gearing, you may have some binding in the drivetrain. Remove the pinion gear and spin the tires. If they spin freely, it's probably fine. Make sure you don't set the mesh too tight when you reinstall the pinion. If the wheels don't spin free, you may have a bad bearing, or something going on inside the tranny.
It really sounds to me like you have a combination of improper gearing AND you're trying to squeeze a little too much run time out of the battery.

[Serius Black]

Oh yeah. You said the motor was brand new, so the timing is probably where it needs to be from the factory.
Work on getting the gearing in the ballpark before you even consider adjusting the timing.

[outsider]

Also, it's not the amount of fins but the surface area of the fins that counts.

[greg_in_michigan]

JasonC:Thanks. I will have to look around at my LHS for some different heat sinks.

Serious Black: The car I am running is a Rustler. I'm not really bashing around the yard, I am right now trying to get my driving skills up to par so I can race at the track that a buddy of mine is building next year. This thing is being run very hard, and at full throttle for probly 90% of the run. I don't have a discharger, and I don't plan to get one any time soon because this battery already has a little bit of cell memory, and when I get serious into my racing, and get some high end batteries from Ballistic batteries, I will then get a discharger.

Outsider: Yes that is true, but the AE large sink has more fins which also means it has more surface area.

[Lotus00]

I had that same problem with my XXX-T so i cut some sections out of the back of the body and covered them with the mesh lining from a swimming suit. then i painted them black. my motor still gets kind of hot, but i can run the whole pack with out a wire fallig off. the mesh stuff looks really cool too!

[Serius Black]

Ya' gotta get a discharger, man. It sounds like you've only got one pack, you should try and take better care of it.
Dischargers aren't just for high-end packs. Any ni-cad battery will develope a memory if you don't cycle it properly.

[roadrage]

Awesome idea lotus!!! I got to try that. Not only do i get better cooling, I get looks to. And since im driving a pan car, I'll also get less resistance because air builds up in the back. Sweet! 11T ruster must also be sweet! :D

[greg_in_michigan]

PLEASE HELP ME UNDERSTAND GEARING!!!!

Right now, I think I have a 13/44 final drive ratio. 84 spur, and a 17 tooth pinion. I found that if I get a 78 tooth spur, and a 20 tooth pinion, I get a final drive of 10.60. If I go 74/22, I get a final drive of 9/14. I think I did it right.

I took the spur gear and divided it by the pinion, and then I multiplied it by 2.72 (The final drive ratio of the Rustler from what I understand) and then came up with the final drive ratio. Right?

I want the most speed possible from this thing. I still don't understand a thing about ratios and stuff.

[RustlerBoy]

Truy gearing it with a 15 or 16 tooth pinion.

[TB01 2NR]

Hey FYI sont get the TC3 heat sinks, those are for motor s mounted parellel to the chassis as you can see moving air goes across the fins. While they may seem cheap, easy and effective which they are but only on a chassis set up like the TC3 or TB01. Best bet is the Trinity those are well made. Also check for a traxxas one that might be cheap.

[greg_in_michigan]

Thanks TBO1. I never noticed that. I guess I will look for a Trinity one or something like that.

I'm going to put my Garnet in right now. I never had problems with that with gearing it 18/78. And it was wicked fast. I got like 10-14 minute run times too. And that was with a Novak Fusion.

[greg_in_michigan]

I put my Garnet in my rustler just 10 minutes ago, and it WHEELIES!!!!! I had onyl a half charged 2400, and my driveway is all wet, and the thing was pullin about 1 inch wheelies right off the line. No reverse to forward of anything. I don't even have reverse on this thing. It's so sweet. I think I will stick with this motor for now untill I can get the gearing figured out for my Topaz.