I have a 3908 e-maxx that was suppose to have the mamba in it and I decided to run the Summit 775 motor because of the torque. After modifying the motor plate and a little grinding on the tranny, I now have the question of what gearing I should run. The stock 68t spur wont reach the pinion unless they make a large one. I'm also running Big Joe series 40 tires. Any help on the gearing for decent speed and torque without overheating?
Big motors like that typically need a 22T Pinion or larger to reach the spur gear. Make sure you get one that is 32 pitch. I'm not sure what the motor shaft size is, I think it may be a 5mm shaft.
Bigger question that comes to mind is what ESC are you going to use with that brushed motor? Brushless ESC's don't or can't run a brushed motor. I've read that some brands of ESC can be put into a "Brushed" mode but I'm not sure about the Castle ESC's
Try the 70t nitro rustler pinion with an 18t spur. I had that with my summit tires and 775 motor. This will give you some clearance issues, you'll have to dremel...
If its too slow, try 21/68 but that may be too much with those tires.
Last edited by Redsawacs; 12-04-2012 at 09:06 PM.
Castle's guide has directions as to how to operate a brushed motor with their brushless ESC's... more brushless ESC's can run brushed motors than most realize.
Whatever it is I just typed... could be wrong.
I was running a 20T pinion on a 68T spur with my 775 motor. After some work in the transmission case I was able to make it work. Not the fastest, but lots of torque.
Not enough space here
Thanks for all the info. I am running the EVX-2 in it. I will try starting with a 20t pinion and go from there. Again, thanks everyone.