from Hacker News

Rodin Bike Wheels

by jorgem on 4/23/14, 2:09 PM with 9 comments

  • by rodinwheels on 4/24/14, 12:41 AM

    Hi guys, a good friend of mine sent me the link to this conversation which is very good and maybe I can add some clarity. Patented 3Drsr is closing the gap between 3D Printing & mass manufacturing for hollow structural parts. 3D Rapid Structural Replication allows us to produce parts not possible with injection molding. In the case of the Rodin Wheels, injection molding cannot produce a seamless hollow wheel with hook bead rim, internal ribbing and variable wall thickness where needed to counter stress. 3D Printing can reproduce the wheel in the same complex form but they are not nearly structural enough, took 32 hours each to build on the FDM printer and ended up costing about $3,000 ea. In contrast 3Drsr will produce, under high temp and pressure the otherwise impossible complex fully structural wheel in under 5 mins for less than $200 each during the Kickstarter campaign. Also it really isn't BS that as the composite material cools it forms and aligns in interlocking chains that make the final cooled part want to hold the solidified state. As for the tooling time, we are not planning on employing rapid tooling techniques which we would normally do for more reasonable sized parts. Thanks for being interested and talking about 3Drsr Technology and Rodin Wheels.

  • by quasque on 4/23/14, 3:09 PM

    Sounds like they've just slapped a fancy sounding name onto injection moulding, given that they specify a 2.5 month timeline for tooling.

    That said, it's likely a novel implementation of injection moulding technique for this particular application, and so I don't mean to sound like I'm denigrating it - but it doesn't seem accurate to frame it as a successor to 3D printing (as the original HN title did).

    Edit: relevant patents assigned to the founder of the Kickstarter campaign - WO1994016911A1, WO1995004666A1; this is definitely injection moulding

  • by devinmontgomery on 4/23/14, 3:18 PM

    I got nothing from the project description, but here's the patent: https://www.google.com/patents/US6516866

    It sounds like a mashup of injection molding and lost wax casting (what they call "lost core molding").

  • by fest on 4/23/14, 3:03 PM

    Once I got to the part about material memory and molecular level, my bullshit detector tripped.

  • by rodinwheels on 4/24/14, 9:40 PM

    jorgem has it right. If you can get your mind around how complex it really is to make the entire wheel hollow with ribs inside with the flowing spokes getting wider as they get closer to the hub area while at the same time the wall thickness is increasing this can not be produced with "injection molding" 3D Printing can make duplicate the shape but the printed wheel is too weak, takes a lot of hours each to make and costs way too much.

    3Drsr Technology sets designers free to make amazingly complex hollow structural parts quickly and at reasonable cost.

  • by taybin on 4/23/14, 3:19 PM

    4D printing obviously. I want this in my hand: https://www.youtube.com/watch?v=5xN4DxdiFrs