I need gearing help!!!

[yzinger02]

Im running a 1518 1250 kv on 6s in a muggy and I cant seem to find the right gearing. I've tried 16,19, and 22 tooth pinions and the 16 was definitely too low and the 19 was too low so I tried the 22 and it was overgeared. I have a friend with a xerun 4274 motor in his FLM emaxx and that motor hardly ever gets over 120F and my 1518 is hitting 170F at times but mainly in the 160F range. Im running a MMM esc and it gets about 115F and my battery gets to about 130F. Please help!!!

[brian015]

Here's what the top speed estimator gives me with your setup with the 19t pinion and, I'm assuming, 46t spur (had to guess on tire diameter):

Differential Ratio: 4.090909090909091
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 19
Total Voltage: 22.20
Motor KV: 1250
Tire Diameter (inches): 5.8
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor Coil Resistance: 0
Spur/Pinion Ratio: 2.42 : 1
Total Ratio: 9.90431 : 1
Tire Circumference (inches): 18.22 inches (462.82 mm)
Rollout: 1.84:1
Total Motor Speed: 27750 RPM
Vehicle Speed: 48.35 mph (77.66 km/h)
Effective KV Value: 1250
KT constant: 1.08 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

That seems like it should be a good setup - 48mph on 6s for bashing. Even with the 22t pinion, it has a top speed of 56mph - which your setup should also be able to handle (depending on conditions - tall grass, for example, would stress it more).

Did you get that motor used (I think I remember that you did)? If so, it's possible that the high temps are due to someone getting it too hot in the past - the magnets lose some of their magnetism and the motor becomes less efficient.

[yzinger02]

Thanks a lot brian and yes i bought it used and the magnet overheating is probably the case. Should i worry about 160f temps??

[brian015]

Originally Posted by yzinger02

Thanks a lot brian and yes i bought it used and the magnet overheating is probably the case. Should i worry about 160f temps??

No, that's not too high - if it doesn't hit 180 I'd just keep running it. My CC1518 in my Muggy usually tops out in the 130 range, though - that's why I'm guessing it's at least possible that your motor has been slightly damaged.

[_paralyzed_]

too tight of a gear mesh or any binding in the drivetrain will cause heat. Is everything good mechanically?

[yzinger02]

Everything spins just fine in the drivetrain. Thanks for all the help and I'm just going to keep running it 19/46 and not worry about a new motor cus it has a lot of power (backflips) so I'm not worried about it.