0.8 Module for Kyosho MP10 and MP10e

The module of a pinion corresponds to its number of teeth in relation to its diameter.

Most of the pinions used on radio-controlled cars are in module 1, a standard used for many years. That's why we're used to using similar transmission ratios in the drivetrains, but also in the central transmission.

The unavoidable 13 or 14 clutch bells, and 45 to 48 teeth ring gears. The same applies to brushless electric versions, with pinions around 14 to 16 teeth.

As with a bicycle, torque is reduced by the ratio used.

If we divide the number of teeth on the ring gear by the number of teeth on the clutch or engine pinion, we get a decimal result which corresponds to the central transmission gear ratio.

Let's take the example of a 46-tooth ring gear and a 13-tooth clutch bell.

46/13=3.5384, which we'll round off to 3.54. We can transfer this value to the table below and proceed in the same way for the other values.

The smaller the number, the longer the gear ratio, meaning smoother acceleration and higher top speed.

Conversely, the higher the number, the more responsive the acceleration, with less top speed.

So, what is 0.8 module?

Quite simply, the number of teeth for a given diameter will be greater.

For the same diameter, a Kyosho crown has 46 teeth in module 1 and 58 teeth in module 0.8. 

As you can see in the table below, the ratios are very close between the 2 possible versions. So your car's top speed won't be affected.

Which gears should we use?

MP10 NITRO VERSION:

If you were to use the original gear ratio of the MP10 TKI3, for example, with a 46-tooth crown and a 13-tooth bell, you'd have roughly the same transmission ratio with a 17-tooth clutch bell and a 60-tooth crown.

Like me, if you like a little more smoothness with the 45-tooth spur gear, go for the 59-tooth crown and 17-tooth bell.

MP10e BRUSHLESS VERSION:

With these new options, you'll need a ratio of 19/58 to match the original ratio.

What are the benefits?

With the 0.8 module, the teeth may be smaller, but when driving, more teeth are in contact at the same time between the powerplant and the car.

The transmission is smoother and more efficient. Your car will therefore gain in driveability, and you'll probably also get a better mileage.

These options are therefore highly appreciated on slippery tracks. 

On high-grip tracks, however, there are no negative points. You can, however, go up in the gear ratio (crown gear with more teeth or bell gear with fewer teeth) to give your engine more "pep" and aggressiveness.

Technical details

The use of the 0.8 module requires more precise, and slightly tighter, adjustment of the tooth gap (gear mesh) than with its equivalent module 1.

Be careful when installing it, otherwise you may damage the gear prematurely.

With a correctly adjusted mesh, the lifespan is identical to that of the original version.

When using 59 and 60-tooth ring gears, it's advisable to use 1mm shims under the differential mounts. Otherwise the ring gear will protrude from the chassis frame and be damaged, or even worse, rocks could get stuck.

How to setup the right gear mesh with Yuichi Kanai:

See you soon for a new tutorial!

The Shark
Reno Savoya