Originally Posted by
Willis99
Quick question, I am new to brushless motors and was wondering if the following is true:
(Quoted from a hobby shop staffer):
"If you are running 17.5 motor, you need to change the spur and pinion to 64pitch. 48pitch is too big to make the right gearing.
64pitch 96t spur and 64pitch 48t pinion will give you the gearing at 4.00, which is good to start.
Internal gear ration of XI is 2.0
96 / 48 * 2 = 4.00 (Spur size / pinion size * internal gear ratio)"
Is this true ? And will the 64 pitch set up work with the car with pulley system, etc?
What motor size was the 48 pitch gearing set up for?
Thanks for your help. I am switching from Tamiya items and am not used to so many choices. Best
W
Well, it's
mostly true. You do NOT need to use 64 pitch to get the correct gear ratio. Several companies (3racing, Integy, Robinson) make 48 pitch pinions with up to 41 teeth (Robinson goes to 47T
but it's hard to get it installed in most cars). Spur gears are available with 60 or 55T, so getting a 4:1 FDR is no problem.
64 pitch gives you finer adjustments, but they are more fragile. If you're racing outdoors, 48 pitch might be a better choice.