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J Smith
01-22-2004, 12:08 AM
I think the reason people are having there stock motors burn up is because they can't handle the torque of the 4wd direct motion drivetrain. To easily test this all you have to do is remove the driveshaft to make it 2 wheel rear drive if possible

That should be the easiest way to tell.

I mean just think about that motor spinning and thinking how instantly you get 4 wheel drive that is a solid 4wd because its a driveshaft. Lots a torque are probally recommended in a motor. The more weight on the car will also probally make the motor need more torque to push it.

If so maybe this will do the trick?

http://www.rcmart.com/catalog/product_info.php?cPath=144_22_506_105&products_id=508

Roelof
01-22-2004, 12:33 AM
Read this:

http://www.one18th.com/forums/showthread.php?threadid=4374

Actually the gearing is to high for a stock motor while the motor does not get much cooling.
The larger spurgear or a smaller pinion (15t HPI Micro), a hole in the chassis under the motor and a huge alu motormount will do the trick

CarpetMuncher
01-22-2004, 01:45 AM
Reading all this about the heat problems, I expected the worst. However, three of us have run stock motors for three weeks now at Indy Slots (this is generally a tight, technical layout) with no problems at all. They run a four-cell stock class, so that may be the saving grace. We're geared 17/36. We've all run 20 minutes or more at a stretch with no heatsinks, cooling, etc. ('til the packs dump, in fact) and still on our first motors.

EDIT: We all have made the A-main each time and had swept TQ's and mains, until the local hot-dog (microed) decided to rain on our parade last week with his RS4 ;). He raised the bar a notch but has a lot more experience than us. We're working hard to narrow the gap. It's nice to have a tangible performance target.

Raydee
01-22-2004, 06:12 AM
4 cells is most likely the difference there. I run 5 cells on my stock micro and if I gear it up from the 17 tooth to the 19 the motor will fry! With the 17 tooth pinion most of the other cars on the track pass me with ease. Wit the 19 they can't but my motor doessn't last the whole 6 min race. I am going to try a hole in the chassis and a cooling fan so I can still run the 19 tooth, hopefully it works. I know my local hobby store has the 42 tooth spur on order so that may help a bunch too.

LtB
01-22-2004, 06:43 AM
I race on 4 cells @ 19t pinion, and the motor can last forever, it is hot, but not HOT hot.. I've run cca 15 min. non-stop with no problem...

CarpetMuncher
01-22-2004, 12:24 PM
That's good news... I may try 19T tomorrow to see if I can get a straight line speed boost.

rchelitek
01-22-2004, 09:57 PM
Also good throttle management hrough the corners will go a long way. I remember doing a test with my micro that went like this. The track i run at can actually be run at full throttle all the way around if you turn in just right. lest say i pull a 6.2 second lap (short track) at full throttle all the way around. I take the temperature of the motor after a 5 minute run and it says 160 degrees. Then i actually drive the car around with good throttle management for 5 minutes with a average laptime of 5.9 seconds. Not only was my lap time faster but the motor read back 115 degrees and i used less capacity out of the battery pack. The full throttle run used 400mah and the throttle managed run used 274mah. My thoughts are purely about effeciency. If your tires are spinning or hoppingaround the corner instead of rolling, then the car is not running efficiently through the corner thus using more Amperage to get through the corner at the same speed. This basically ends up back in the world of suspension, weight balance, and weight transfer setup. My friend does run the x-ray with the stock motor and his motor never gets above 120 degrees.

CarpetMuncher
01-22-2004, 10:21 PM
VERY interesting post! This sounds exactly like Indy Slots. You can often drive the layout flat-out, but can be just as fast with good throttle control. And you're right--things stay much cooler, too.