RC Transmission capacity and power classification

Transmission capacity and power classification

Customer reviews
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Power to weight ratios are very interesting. The full size Pz111 had a power to weight ratio of about 12 HP/tonne, the dreaded Tiger 11 was only 10HP/tonne and the Panther 15HP/tonne. The post war Centurion was little better at 13HP/tonne. Today's gas turbine powered MBT's are in the order of 20HP/tonne while the lightweight Scorpion is the champion at 26HP/ tonne.

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WOT                  Jump
Wide Open Throttle (WOT)


Now lets compare that to some scale model tanks. A 30 kg 1:6 Stuart with a GX31 will be an enormous 40HP/tonne. A 50 kg 1:6 Panzer-111 with the same GX31 will weigh in at 24HP/tonne. It is interesting to compare these figures with, lets say, a typical electric 600watt 110kg Panther, these end up at only about 7 or 8 HP/tonne. The conclusion is that the I/C engines should have equal or better performance than with electric power, but it is all too easy to throw everything away with inappropriate gear ratios. A high powered lightweight is very agile with a high reserve of power and are therefore very forgiving. When determining the gear ratio(s), start off with the maximum speed at scale for your model at the maximum rpm of the engine you are using.

Indication of the capacity of the various units:


CG & CT1          Suitable for tracked vehicles up to 30kg.
CT2 & CT3        Gearboxes suitable for power levels 500 to 750 Watts (1.0 HP).
CG2                     Suitable for tracked vehicles up to 50kg.
CG2DD              A CG2 fitted with a Double Differential (Sturmey Archer’s) suitable for tracked vehicles up to 100kg.

CG3                 Double differential steering system suitable for tracked (1 to 6th scale) vehicles up to 150kg.


For heavier i.e. bigger scale vehicles commercially (surplus) gearbox and transmission components can be used. In bigger scales size is less of a design constraint so one can use components of go-karts, ride-on lawnmowers, mini bikes even car transmissions andwhatyoumayhavemore.

For example;


50 to 120kg Differentially braked transmission using  a ride-on lawnmower transaxle ( Peerless, Tecumseh, or John Deere etc.)


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100 to 500 kg Differentially braked transmission using a go-kart or lawnmower differential.


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