undergearing brushless ?

[nickhudson]

can anyone confirm that undergearing a brushless motor will generate excess heat in a similar way to overgearing ?. i'm not talking about a silly low gear ratio (21/78 in an X6) running lipos and an orion 7.5 2008 spec motor.

i will be playing with the gearing anyway but thought i'd ask if anyone else had experience of this.

the motor was running fairly hot on this gearing last sunday (hot day) with cooling holes in the shell - approx 150 deg F (65 deg [ish] C)

it did seem to be topping out on acceleration about half way down the straight but seemed ok on the rest of the track.

[sparrow.2]

That is a wee bit short and yes it will overheat if run too short as well. Are your temperature readings a little off? 150°C would have melted everything :woot:

[super__dan]

Is it bonded or sintered? With lipo and bonded that's probably likely, the motor in an X6 gets warmer than most 2wd cos it's inside the shell. That said that's actually under the max temp limit I've been advised to comfortably get the motor running at. You'll probably find by gearing up it won't get any hotter but performance will be better all round. I run 24/78 in mine with a sintered 7.5 but not with Lipo.

You've got deg C and F the wrong way round.

[nickhudson]

you're right about the temp mix up of course - proabably shouldn't post late at night :blush:....

thanks for the replies - much appreciated

i'll try a couple more teeth on the pinion and see what its like