Tamiya TT-02 spur gear adapter

thingiverse

Because I wanted to use a 68t spur in my stock TT-02B, I decided to design and 3D print an adapter myself. This adapter makes it possible for me to use all Tamiya spurs and perhaps many aftermarket spurs without needing the high speed gear set and aluminum prop shaft and cups upgrades. This adapter requires 4 M3x5mm countersunk bolts (or something similar in imperial measurements). Since the hole in the 68t spur has a diameter of about 9.5mm, I needed to shave a bit off the stock axle pin, which is 10mm long. The stock axle pin is made of hardened steel, so this takes some effort. I printed this adapter in PLA with 100% infill and have tested it with a 68t spur, a 17t pinion, and using a 13.5 turns brushed Tamiya Dyna-Run motor on 2S. So far, it has survived, but more testing is probably needed to say for sure that PLA is strong enough. I'm not designing or intending this adapter for competition use, even though I'm pretty confident it will be reliable and durable enough. If it breaks during your glorious seconds of fame at pole position, don't come after me.