I’ve designed this bearing seat adapter to fit 6901 bearings to 608 bearing seat longboard wheels. Essentially doing away with the issue of tiny ball bearings like the Skate Kastle kit. I’m looking for feedback on the design, and any recommendations on where to get them CNC milled. Initial pricing I found was around $200 USD for 8 plus shipping. If there’s enough interest I’d consider doing a group buy to bring the price down but would need at least six orders,
So far I’ve tested fitted with 3D prints on Duality trucks with single bearing pulleys and Matrix 3 trucks which need bolt on pulleys.
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Ahaa ! someone else with the good 'ol electric flywheels.
Am I correct in assuming that you have the extended 12mm Matrix Axles ? I asked MBS whether longer 10mm axles could also become available but I fear there is little demand for them.
Yours is an great idea but I would prefer longer axles and to go down to 10mm as I’m not planning on off-roading, doing crazy jumps or entering a donut eating comp for massive weight gain
It would be interesting to see how the quote for your design compares with a 10mm / 70mm length axle quote huh ? I couldn’t find anyone in London
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My first question is, why CNC? Seems like that may be introducing a barrier for you.
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Just the standard length axles were used, agreed 10mm axles is probably easier. Yeah an extended axle would be required for bearing wheel pulleys on Matrix IIIs, but the Duality trucks already come with extended axles - so not needed there at least.
mainly for strength reasons, I’d assumed 3d printed parts wouldn’t hold up to impacts and road vibrations.
I feel like he was implying that maybe having it lathed would be cheaper/easier 
Maybe Stanton would do it for you 
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I’m just seeing that $200 for 8 price.
And you know, the core of the wheel is already plastic, it only needs to be as strong or as accurate at that, anything past that isn’t really adding much.
3D printed FDM plastic I think could be strong enough, especially since everything is in compression here. But it also ages weird sometimes, and gets weak for no reason.
People are less prone to buy into something like that.
Having it printed out of sintered nylon, especially with a CF nylon, I’m sure (guessing) would be strong enough, that may be able to deliver a better price point, and could still have the feel of a real product.
I like the lathing idea, that has the potential to be pretty streamlined
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Yeah fair., I could simplify the design for lathing - removing the cutouts, they were there so that you could fit kegel pulleys, I like that nylon printing idea, I’ve never printed in nylon so I’ll look into that.
Ah, gotcha, lathing might be easier - I’d prefer someone a bit more local… 
Sintered nylon would be through a 3D print service. SLS printing.
Filament 3D printed nylon still has a lot of the drawbacks of FDM printing, but nylon filament also tends to be pretty flexible. Might be doable with carbon fiber nylon filament to get the stiffness where it needs to be. But not all CF filaments have enough in it to contribute to stiffness.
Nylon is expensive filament, and CF nylon even more so. And it shrinks, which means you need an enclosure and you may need to calibrate to get everything just right on a print like this.
And of course you’d need a hardened nozzle as well.
None of that is to discourage you, but tackling structural and dimensional nylon printing is a little bit of a commitment.
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