Whole gear drive housing is CNCed by Al6061 t6 & hard anodized
There 4 small angular contact bearings for slave gears.
1 small angular contact bearing for motor gear
1 big angular contact bearing & sealant bearing for wheel gear
Motor gear/ Wheel gear made by steel (will use pom wheel gear next version)
salve gear made by POM
Helical, 20mm widths gear
Feature design:
*Claw coupling for connecting gear drive and hubs, reduces the impact for gears when it running and it can quick release the hubs. (housing CNCed by al6061t6, padding printed by tpu)
*4 Gears can extend the gear use life, due it increased the gear contacts and divided the transfer power into two slave gears.
*Angular contact bearings for all the gears, made the gear drive running more precision
I love the aesthetics of these drives. I just worry about things getting caught in between my tires and my gear drives. I’d prefer flat screw heads slightly recessed. Though, this does look very nice.
Epic! Would love to see the insides, how assembly works
Edit: It’s already in the first post, preview didn’t load for some reason
I expected a 4-gear drive to have double the reduction, interesting to see a design like this! Having the motor further from the hanger would definitely be beneficial on RKP trucks / urethane drives. Not sure why that was needed for Matrix 2, but cool!
How do you make sure both middle gears are engaged instead of just one?
There are a number of reasons why Acetal plastics are a great choice in wheel gear at this scale of application.
Not really accurate to call it a downgrade, just a specific material choice that brings certain pros/cons vs steel on steel (which has it’s own pros/cons).
@Ean.esk8 this design looks great! Super excited to see how this works out, and always fun to see new ideas in the mix.
Steel gears can mean a lot of things…mild steel (low carbon 1018) maybe 1018 case hardened at the teeth, maybe 4140 prehardened, maybe tool steel like A-2, D-2, or S-7.
High strength-to-weight ratio, high resistance to wear, the ability to enhance the physical properties through heat treatment, and competitive pricing.
I’d also case-harden the pinion but use medium-carbon steel for the gear that’s not hardened.
I’d also case-harden the pinion but use medium-carbon steel for the gear that’s not hardened.
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I like that, what do you mean by medium-carbon steel?
Just wanna chime in that a case hardened pinion and alloy steel wheel gear is the way to go.
Mine are 4140 steel, pinion nitride hardened, wheel gear as machined.
Steel gears offer the highest power transfer possible if space is limited (which it is). That is where I see the real advantage as our boards are space limited (especially in urethane boards). For eMTB gear drives, I think acetal plastics are a good choice because there is much more space to work with.
Cons are that they’re heavy and have unforgiving harmonics. They require rigidity to perform smoothly.
Personally I think the material choice for the wheel gear is just 1 of many important design considerations. People get way too fixated on it. It is proven that both POM and steel work well.
The hundreds of Kaly & Lacroix production boards actively in use over an accumulated hundreds of thousands of miles would be evidence weighing heavily against this statement being true.
I’ve personally commuted full-time on an OG Kaly POM/Steel geardrive for over 10k miles without ever breaking a tooth. In fact, across all of my geardrives I’ve never had an issue.
Not saying it can’t happen through mis-use, but to say that POM/Steel is inadequate for esk8 geardrives isn’t accurate nor backed by real world results. The situations that can break POM wheel gears can also break steel (ie: high rev unloaded slammed to ground) and aren’t within normal operating spec anyway.
I’m also not speaking against steel/steel solutions, it’s a matter of spec, preference, application at hand. But seems odd to disparage a clearly functional design choice (POM/Steel) given it’s prevalent use in esk8.
If I was in Germany, I might want plastic gears, or direct drive instead, just because of legal issues and noise.