FRC125, 2" Printable Mecanum (aka V.I.W.) Release (2019-2020)

The NUTRONs wanted to take a moment and drop these files into the wild before the heat of kickoff is actually upon us. We developed a printed 2" mecanum wheel that we were pretty happy with over the last 2 seasons. We first uncovered the wonder of the vectored intake wheel in 2014 and since have been deep in the V.I.W. (vectored intake wheel) game, particularly with printed parts. Even if not actively trying to ‘center’ the game piece, we’ve found capping an intake roller with a mec wheel helps to grab when out on the extremity of the roller.

Printing small mecanums makes a lot of sense if the game and game piece calls for it:

  • Intake rollers tend to be longgggg, so outfitting an entire roller with mec wheels becomes expensive
  • Intake rollers tend to get messed up, so having cheaper replacements also makes sense
  • Because the wheels can be assembled, they can also be disassembled, which makes them easy to be repaired, etc
  • Mecanum wheels tend to get heavy because of all the parts/pieces, controlling the weight with your own plastics is a big plus

There are 5 printable part files in total: LEFT-A, LEFT-B, RIGHT-A, RIGHT-B and the ROLLER.

Each individual wheel requires:
QTY (5) of 1.5" long, 1/16" diam, dowel pins
QTY (5) of #0 Thread Forming Screws (for plastic) - it’s possible to use fewer screws if you’re feeling lucky
QTY (5) of the printed ROLLERs
QTY (1) of a wheel’s “A” part
QTY (1) of a wheel’s “B” part

Tips/Tricks:

  • Due to the size of the hole in the individual rollers, we recommend chasing the printed roller with a drill bit to get a nice free spinning fit. We’ve had tremendous success with this technique making nice, free-spinning rollers.
  • The rollers can be a bit tricky to print, we’d recommend a raft for the printed part, or a support tower if you’re having issues

These wheels were used successfully in the 2019 season by the NUTRONs, 1678, 3476 and 1323.
We hope they help other teams in the future!

Without further adieu the STL files can be found here: https://drive.google.com/file/d/1xv5hIl8pUSDNbyTBSXNPV_aDzjY6zR6f/view?usp=sharing

STEP files here:
Right: https://drive.google.com/file/d/1P6F_jfHLSCmsnUrW3_ajvnYv_zUl2-JQ/view?usp=sharing
Left: https://drive.google.com/file/d/1LjsXnLDHOHSd92crhBou3zngerlbahTb/view?usp=sharing

Feel free to reach out if you have any questions/issues, or find anything interesting in the design. We love hearing from folks who used them and to hear any suggestions to make life easier in the future.

-Brando

111 Likes

This mecanum is dope. 1323 loved using it.

If we were gonna use a printed design this would be it.

3 Likes

What material are you printing each part with, and what’s the strand orientation on the rollers?

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Since you guys have used this printed wheel, what is the weight difference between this wheel and the aluminum mecanum wheel WCP sells.

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The wheels in the photo are PC, both hub and roller. However we’ve successfully ran these parts in PLA, Tough PLA, Onyx and PC (hubs and rollers).

Roller print orientation is pretty straightforward, like the image below.

  • Doesn’t need support
  • Better dimensional control over the profile of the roller (more round wheel)
  • The nature of FDM and printing circles makes for a nice glidy surface due to contacting on ‘points’ of plastic, versus a complete cylinder

4 Likes

Not sure, WCP wheel is heavier. The WCP wheel is thin steel with molded components.

2 Likes

Thanks for sharing this, we’ve already got our mcmaster order in and have some printing on our MarkForged, can’t wait to try these out!

2 Likes

We’ll have to try them out on ABS since that’s all our 3D printer can handle

Thanks for the release Brando, these wheels really took our intake from meh to touch-it-own-it.

We printed ours out of PLA+ and abused the heck out of them through 4 events and countless hours of practice. None ever broke, jammed up, or cut into the game pieces, a problem we had with other vectored wheel variants.

6 Likes

We loved using these wheels this season. They held up much better than the fingertech wheels we were trying to use at the beginning of the season.

Thanks 125!

-Mike

10 Likes

Are these exactly 2" like the WCP ones or 2.079" like the ThriftyBot ones? That could be very important for packaging reasons.

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FYI - Got a few requests, so I’ve added STEP files above for the Left and Right versions of the wheel to the original post.

-Brando

7 Likes

Thank You

These wheels are awesome. Thanks for sharing the files, Brando.

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Thanks for sharing, I’ve seen this design in season and like it a lot.

Very happy with how these came out, looking forward to doing some testing!

4 Likes

In your experience, how well do the printed rollers of different materials grip objects? Have you found certain materials that grip better than others? Or any that need additional grippy material on them to make them work?

2 Likes

One thing we’ve found is that if the game piece has any sort of ‘tack’ to it, and you’re trying to move it sideways, having some slip between the roller and game piece is actually quite nice. There’s definitely a balance between how well you can translate an object sideways, and how well the rollers grip.

That being said, we’ve had a lot of success messing around with rollers. We had an FTC application this fall where we printed TPU rollers, with PLA ‘axle hubs’ to get a much more grippy baby mec.

We’ve also printed different rollers that allows us to slide over things like surgical tubing, heatshrink or other grippy materials. A lot of possibilities. Makes it nice to be able to try things pretty inconsequentially and find something that really works for your application.

-Brando

20 Likes

This looks like an amazing printable design. How are the pins held in the hubs? Just from a brief look at the CAD and the images above, it seems like they could just slide out over time.

1 Like

Do you think it could work with wooden dowel instead of steel?