As a matter of interest, I know a car’s diff gears are also spiral crown wheel and pinion. But they are unidirectional. By that I mean they can work in reverse (obviously) but it is for instance not a good idea to do heavy 4x4 recoveries in reverse because of the high torque load. It will strip the crown wheel.
Are these bi-directional?
Sorry, I am not sure I understand what you mean.
But I am sure it can be driven in reverse
That’s exactly what I needed to know. Thanks.
Just wanted to update y’all on the final design and how things are going. @MorrisHsu did verify the new-new-new design and I have them here ready for install, which I’m doing now. We determined that it would probably be a good idea to switch machine shops cause this one seemed to not be very good at what they’re doing…
When Morris contacted the machine shop about these problems they refunded his money right away lol
Anyways there’s a notable change that I’m testing, it might not end up being the final product anyways, but the gears in this version are no longer spiral. They’re simply bevel. Ive yet to see how this will affect performance, and if it’s negative he can switch back easily. Will report back!
what was wrong with the cat’s whiskers? 
Thank you for all your hard work on this product and for updating us. I really hope this gets figured out. I’m really excited about this product. Based on the time period that you’ve been getting all the beta versions, do you think this will be ready to hit the market by Christmas?
I would say so. I’m assuming I won’t have to do another round of testing after this, but we will see.
I forgot to mention that Morris now includes thicc spacers to take advantage of the longer axle on TB218s. So the gearboxes now sit wider apart on those.
Aight so here’s the latest:
New drive kit installed, it works well for the most part. I sealed the mounting hole with heat resistant silicon and added grease this time. Even a little bit made a big difference, and the seal made it so much quieter. Also the new mounting mechanism forces the mesh to be exactly perfect, so it runs super smooth as well.
As expected though, aluminum is absolutely too soft for this application so Morris is switching back to steel spiral bevel gears like the previous kits.
Thanks @sofu for her help.
She patiently and professionally helped me complete the test of this gearbox.
This was very inspiring and instructive, thank you and @sofu for this thread development.
Btw this design is lit.
I would say “enough”, though I didn’t measure. The gearbox is fairly compact but I wouldn’t go anywhere below 90mm on the extreme side
Thanks for all the praise 
Spend a year testing and improving
I will start making this gearbox.
I know these are caliber compatible, but doe that mean they’re also boardnamic compatible?
Do you know a final price yet?
Sorry, I can’t be sure that they are compatible, because I have not tried it.
The Gears Drive Kit (one gearbox) is priced at 160usd + shipping
Awesome. There was mention of switching shops so I wasn’t sure if that would have changed the price
As long as it’s the caliber hanger profile it should be ok. Morris includes thicc spacers for TB218 trucks due to the longer axle, so as long as the Boardnamic trucks are fairly similar they should work just fine.
