[Tibbs]

So what your saying about meshing, what ever gear I buy I can build the motor position to suit?

To a point, you are correct, but, as you have indicated that you wish to build sidewinder configurations, the size of the motor, specifically the width of the motor can, will dictate the diameter of the gears you will need to use.

Eg,.......Slot-it sidewinders (130 sized motors) come with a 6.5mm pinion, coupled with an 18.0mm Spur,....this provides enough distance (the diameter of both gears combined) to allow the gears to mesh properly, while allowing the rear of the can to clear the rear axle.

When using a "130" sized motor in a sidewinder configuration , the important figure is the  combined total diameter of both the pinion and Spur, so in the above example 24.5 mm (6.5 pinion + 18.0mm Spur).........so, any combination of pinion/Spur diameters that add to 24.5 will provide adequate motor/axle clearance and mesh.........so,.......you can use a 5.5mm pinion with an 19.0mmm Spur, a 7.0mm pinion with a 17.5mm Spur,...etc, etc.

A narrower motor (FF050), will allow the use of 4.5mm pinions coupled with 16.5mm Spurs,........with any set of gears with a combined dia. of 21.0 mm (4.5mm + 16.5mm) working just fine.

The above examples are for "pure" sidewinders,.........you can "cheat" a touch as does NSR/Thunderslot  by using a slight angle (2 degrees) on their motors in relation to the rear axle,...........this allows for the use of slightly smaller diameter Spur gears with in turn allows for smaller rear dia. tires, lowering the cg. and improving handling.

Cheers
Chris Walker

Here is a sidewinder using a 6.5mm pinion, and an 18.0mm spur,........just enough rear axle/motor can clearance





A  plastic MRSlotcar chassis (050 motor) using a 4.5 mm pinion and a 16.5mm Spur.



Another using a 6.5mm pinion and an 18.0mm Spur

Ah Chris, thank you so much.
I found one of your chassis pics on HRW, your explanation is perfect.
Thank you very much for taking the time to explain it.
Kind regards
Tony