Ask Cub Reporter, Version 02.17.2010
Dear Cub Reporter, Audi R8 V-10 or Ferrari 458?
Hey Elliott, thanks for writing in. Ya know, the Audi sure is an awesome piece of machinery no doubt, but it’s not a Ferrari, nothing else is, so if you have an extra quarter mill sitting in the bank, there isn’t really a choice. To buy anything other than the prancing horse would be just plain asinine.
The brushless motor I put in my Strike runs around 200 degrees, what pinion should I put on to run cooler?
What’s up “Mista”? LOL. Gearing is so much fun! Here’s Cubby’s golden rule on gearing- start with the smallest pinion you have, monitor temps, and work your way up in pinion size without going over 160 degrees. Unfortunately for you, this rule won’t work. Why? Because if you’ve been shooting the temp on your motor, and it’s 200 degrees on the outside of the can, it’s gonna be much hotter than that on the inside. And because your motor has most likely been well over 200 degrees your rotor/magnet has gotten too hot and has been ruined. When you get the magnet inside your motor too hot, the kv of your motor will actually go up, but your motor efficiency goes way down. What that means to you is that your motor will pull more current for the same amount of power, and no matter how you gear it, it’s going to run too hot. Use your current motor for a nice paperweight (or replace the magnet if possible) and buy a new one. Oh and, don’t forget Cubby’s golden rule of gearing when you install your new motor.
YOUR Cub Reporter