by HomeRacingWorld » Thu Dec 06, 2018 8:13 pm
Mike, well the short answer is YES you can use CB Design or Slot.it "15x8" wheels and your axle will be close enough on center of the motor shaft without the need for a hypoid gear.
I have used them many times and the gear mesh is smooth enough and with break-in, well even better.
The longer answer... :doh:
Standard FC-130 type (Piranha) and FK-180 (Jaws/NC-5) motors have identical motor shaft height when set flat. Or as close as it gets.
"Official" specs from China indicate a motor can height of 15.1 to 15.4 with a +- .03. Well...you can take that as gospel if you want to :)
In my measurements here, my average is 15.30 MM.
It DOES VARY from brand to brand in the slightest.
This is WITHOUT a wrapper/label/paint/anodized.
With some labels/paint, the average is around 15.50.
When my setup wheels were made they were turned to a 15.50 MM OD.
When you install them on an axle and line the axle with the motor shaft, it is about as close to dead on center as you can ask for.
The standard "15x8" wheel has an OD at the rib of 15.875
So the size difference is VERY slight and like I said, you can get away with it.
But you can make them more accurate by mounting them in your Razor/Truer and sanding them slightly to bring the OD to around 15.50. Does not take much!