TT05 Gearing Help - What fits?

[Derka 2]

HI guys,

I have recently bought a used TA05 Raybrig NSX and it came with a 18T pinion and the stock 70T Spur gear. I believe the 70T spur is Tamiya 0.6 Mod pitch?

I ideally would like to change to 64DP or 48DP gears.

I currently have the kit 70T 0.6 Mod spur with an included 18T pinion which I can only assume is a 0.6 Mod pinion as I had no stripped gears or horrible sounds last night.

70/18 = 3.88 x 2.25 = 8.75 FDR which was just a tiny bit slower than I wanted on our tight carpet track. I'm running the stock Tamiya Sport Tuned Motor.

I am familiar with gearing to get speed/acceleration but need some help choosing a combination of spur and pinion to get the FDR of 8.5 and lower if needed.

The reason I ask is because I tried my 48DP 69T Spur with a 19T pinion and I couldn't get them to mesh, I needed a bigger spur or pinion (Or both!)

Could anyone point in me tried and tested gearing as far as it will mesh up OK?

I have seen the 105T 64DP spur mention a lot, but would  27T through to 30T pinions mesh up OK? This would give me a FDR of 8.7 to 7.8.

 

[Derka 2]

Right, I have spent a few hours coming up with something which I believe works as I've tried it out with a gear setups I have found people using via Google.

 

Firstly, the stock 70T 0.6 Mod Spur gear measures in at 43.2mm diameter.

Keeping to idea of not going much larger diameter wise, otherwise the spur gear protrudes out the chassis.

48DP biggest spur is a 80T which measures in at 43.39mm

64DP biggest spur is a 105T which measures in at 42.46mm

Now, I hope you can keep up with this...

According to the Tamiya TA05 Manual (Raybrig NSX 2005 - https://www.tamiyausa.com/items/radio-control-kits-30/4wd-belt-drive-on-road-(ta)-36200/rc-raybrig-nsx-2005-58353

the following pinions (0.6 Mod) can be used with kit included 70T 0.6 Mod Spur.

21, 22, 23, 24 and 25*.
Calculating the diamater of each of these 0.6 Mod pinions; (*Side note. My TA05 came with a 18T Pinion which its diameter is 12mm, so its safe to assume pinions from 18-21 Fit)

*18T 0.6 Mod = 12mm
*19T 0.6 Mod = 12.6mm
*20T 0.6 Mod = 13.2mm
21T 0.6 Mod = 13.8mm
22T 0.6 Mod = 14.4mm
23T 0.6 Mod = 15mm
24T 0.6 Mod = 15.6mm
25T 0.6 Mod = 16.2mm

Keeping up so far?

 

If you combine the total diameter of the 0.6 70T Spur and smallest and largest pinion you can gauge a safe zone for what size diameter combination you can run.

70T 0.6 Mod Spur 43.2 + 18T 0.6 Mod Pinion 12mm = 55.2 is the smallest total diameter you fit. You can of course fit a smaller spur gear and make up the difference with larger pinion.
70T 0.6 Mod Spur 43.2 + 25T 0.6 Mod Spur 16.2mm = 59.4mm would be the biggest combination of Spur and Pinion.

So to clear it up, the smallest combination of spur and pinion is about 55mm and the largest is about 59.4mm.

 

If you wanted to run 64DP Gears, the biggest spur would be a 105T and you could fit 27T through to 39T Pinions.

if you wanted to run 48DP Gear, the biggest spur would be a 80T and you could fit 20T through to 29T Pinions.

For both of these you can reduce the teeth count (also reduces the diameter) and fit larger than the biggest pinions above, as long as the total size of both the spur and pinion fall between 55mm and 59.4mm

I cannot check to see if there much more movement either side as I don't have the means to test, but let me know if you find this useful or if its wrong!