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Unread 26-10-2016, 21:13
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Billfred Billfred is offline
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FRC #5402 (Iron Kings); no team (AndyMark)
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Re: [FTC]: Is this Mecanum wheel configuration acceptable?

Quote:
Originally Posted by ImMoMo View Post
Hey!

So I'm a college mentor for my old team, and I'm helping out with FTC.. so it's pretty late into the our build season, and we don't have a substantial drive train design..

So using what little CAD I learned in my intro CAD class in college, I decided to sort of mock up a way of connecting the NeverRest motor to the Mecanum wheel..

The students want to go towards the Mecanum wheel route, so we're going to try to CAD and assemble a similar structure, using
- NeveRest motors
- Andymark Mecanum wheels
- Tetrix Wheel Hub

It seems like it all fits well in CAD, but I would like another opinion if these parts would be compatible.
They say that if you say "AndyMark" three times we show up. Or sometimes just once...

Some considerations I see:

1) Those parts will all mate, but we'd suggest the Nub over the Tetrix hub for the D-bore. Set screws aren't a good look.
2) On one hand, cantilevered wheels will give you some flex that is desirable in mecanum drives. On the other hand, supporting both ends is beneficial as weights increase (especially for prolonging motor life). Our TileRunner chassis is certainly one way to accomplish that (and speed the motors back up, to account for mecanum inefficiencies), whether you buy it or just draw inspiration from it. A second Nub on the other side of the wheel and D-shaft into a bearing block would accomplish this too. And as Gus says above, make sure it'll actually clear (or just flip the drivetrain over).
3) You don't mention which NeveRests you're using. 20s are on the ragged edge in direct-drive applications for FTC-weight robots; teams using 40s during Fight Night had no problems, while teams using 20s were breaking gearheads (admittedly, under higher-than-usual voltages and abuse).
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William "Billfred" Leverette - Gamecock/Jessica Boucher victim/Marketing & Sales Specialist at AndyMark

2004-2006: FRC 1293 (D5 Robotics) - Student, Mentor, Coach
2007-2009: FRC 1618 (Capital Robotics) - Mentor, Coach
2009-2013: FRC 2815 (Los Pollos Locos) - Mentor, Coach - Palmetto '09, Peachtree '11, Palmetto '11, Palmetto '12
2010: FRC 1398 (Keenan Robo-Raiders) - Mentor - Palmetto '10
2014-2016: FRC 4901 (Garnet Squadron) - Co-Founder and Head Bot Coach - Orlando '14, SCRIW '16
2017-: FRC 5402 (Iron Kings) - Mentor

93 events (more than will fit in a ChiefDelphi signature), 13 seasons, over 60,000 miles, and still on a mission from Bob.

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