Tamiya TT02 17.5 21.5 and VTA Blinky Gearing

I've really enjoyed playing around with the TT02 over the last year. It's a very versatile chassis and the refinements over the TT01 help ensure that this is a much more capable car than it's predecessor. (here is the Review we made)

It's also good for those who buy an RC car and then want to sample racing at a local club, and one of the most popular classes are called Blinky races. Here you cannot change the Esc's settings, but you can gear the car to help change your speed etc.

17.5 Blinky is a popular class and ideal for beginners as you just need to gear your car to general ratio that everyone else uses and you are able to have a fair balanced race, where you can learn car control and the all important skill of keeping corner speed.

In smaller clubs a FDR (Final Drive Ratio) of 4.5 is quite popular, larger clubs it moves down to 4.0 and it can go all the way into the low 3's for larger outdoor tracks.

How do I calculate the FDR?

To calculate the FDR is very simple. You use the following simple equation:

Drive Ratio (Spur/Pinion) * Internal Ratio.

In the case of the standard kit TT02 you have the following

• 70t Spur gear
• 22t pinion
• Internal ratio = 2.6

So your FDR calculation is:

70/22 = Drive Ratio of 3.18 then you multiply it by the internal ratio of 2.6 to get the FDR 8.27

As you can see with the calculation, you need to change your FDR quite significantly to get to the FDR range for Blinky

Making a Blinky TT02

In stock form, the TT02 is unable to have the gearing needed to really compete in these blinky classes. The following items will allow you to modify your chassis to get a suitable range from the low 3's to the high 5's

The Items you will need are :

• Tamiya 54500 High speed gear set 
• Yeah racing TT02 adjustable motor mount
• Suitable Spur and pinion to get the FDR range you want. 

Tamiya high speed gear set

I did not use the included Spur, I used a selection of RW racing 64dp gears

The high speed gear set comes with a spur gear holder, This is something that you could never do with the TT01 and this is an important part for making the car more adjustable. With this you can fit any std 4 hole spur gear.

For the gearing we are looking to achieve you will not want to use the included 68t gear. I use a selection of RW racing superlite v2 spurs. In the following I used 82t and 70t (64dp gears) to test a range of gearing FDR's

All fitted ready to be installed

Adjustable mount

The TT02 adjustable mount is very cool, and when coupled up with the facility to mount any spur it gives you the same freedom to adjust your gearing as any high end chassis.

It not only allows the freedom to gear your car how you want, but also acts as a heat sink

Fitting in the car

Here you can see a 53t pinion and a 70t Spur gear

In the pictures above you can see I fitted the smallest spur I could find (70t) and the largest pinion I had (53t) these give a FDR of 70/53 = 1.32 (Drive Ratio) * Internal Ratio (2.6) =  3.43 FDR

The above fits with no modifications to the chassis, although you will need to file a little bit off the upper gear cover if you fit a pinion 50t or over as it may rub against it.

I just cut the area out, and then covered it with electrical tape.

I actually cut this area out (to take a look at how much space my 53t pinion needed. If you file away you can fit in the 53t pinion without making a hole. Although it is also just as easy to make the hole and cover it with electrical  tape to allow you to fit bigger pinions :)

Covered, and ready for even bigger pinions if ever needed.

Conclusion

So there you have it. Its very easy to modify your TT02 to run any blinky gearing you need. I hope to give it a run at Halifax soon to get some lap times and see how it goes. Maybe I will do this years national with the TT02 ;)