Dual NEO 550 versaplanetary gearbox

Just an idea I came up with, since the 550s are unshielded outrunneers. Allows for two NEOs to drive something, while only needing one versaplanetary gearbox without a COTS dual-550 gearbox (such as this: http://www.banebots.com/product/BB150G-1.html).

If you don’t have access to a router or waterjet to make the metal bracket, it should be fine if it is 3D printed out of some sort of relatively tough material, as it shouldn’t endure too much force.


I don’t think they’ll like having too much torque that far away from the bearing/mounting - maybe some additional support would be good. Cool concept though!

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This is neat! I always kind of worry about cantilevering loaded parts off the end of outrunners, especially with such a thin bracket, but I like the idea a lot. Perhaps an elegant solution would be to have some kind of pulley that clamps around the can of the motor that could be mounted closer to the motors face + a thicker or more supported bracket. With the right belt selection one could easily be 3d printed!

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In practice, you could prove be right about too much force from being that far away from mounting, but I think they’d be fine with the bearing. On REV’s website, they mention that there’s two bearings in the design; one in the front of the motor and one in the back.

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I’m gonna go mess with that idea a bit. That’s a really good idea. I’ll let everyone know later how it turns out.


This doesn’t actually help too much as you’re just shifting more load into the structure of the bell itself. I would spring for something like a simple plate with bearings to interface near the back of the motor and distribute load.


100%, I think the effectiveness would be semi dependent on the bearing arrangement of the Neo 550s, which we don’t know yet. It was more of just a thought on how to keep the design fairly similar and complexity/compactness while helping a bit with the cantilever issue.

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I’m thinking that would be very fast for chain. Perhaps belt would be a better choice.

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I completely overlooked that, thanks for warning me. I believe REV sells belt pulleys that fit on the back, I’ll check in just a moment. If they do, I’ll try to integrate them with the current modifications that I’m making.

“Whaaaat?” “I can’t hear you over that terrible racket”

I still occasionally have nightmares about the sound of 973’s 2016 shooter.


I love this idea. Good questions already asked about its viability, but only the eventual release of more info or the motor itself will likely let us know for certain. My question is would the shaft of the 550 be able to handle twice the torque?

I think it would be able to, assuming it’s made out of the steel that most motor shafts are made out of. If anything were to fail here, I think it would be the connection between the primary NEO and the versaplanetary it is connected to. This could provably be avoided by using a set screw connection instead of VEX’s friction fit connection.

Well, that took longer than expected but I got it done. I implemented a 3D printed bracket to mount the secondary NEO to the versaplanetary gearbox, and added a second bracket (green in the picture) that holds two bearings. The bearings are to hold the two pulleys a fixed distance apart as to not harm the NEO. A rivet would be put in the hole circled in red to make sure the bracket doesn’t flex too much. There is an identical flange on the bottom of the part.

Edit: although it doesn’t look like it, the bearings do touch the pulleys. The pulleys have little nubs that poke out and go into the bearings. If you were worried about them having too much play in the system, a 3D printed spacer could easily be added.

Edit 2: I made the 3D printed bracket not a triangle, and it looks wayy cooler now. Shown in the second photo.


If the green part is only to keep the bearings a fixed distance apart, there’s not really much need to mount it to the versaplanetary. If you remove that, it also wouldn’t be too hard to add an additional NEO 550, though shoving that much power through a planetary gearbox might not be the best idea.

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Yeah, I’d be worried about that much power through a single versaplanetary. I only mounted it to the versaplanetary for convinience. If you need that much power, a single full size NEO would probably be cheaper and smaller than three NEO 550s (now that I think about it, it might also be cheaper to use one full NEO than this gearbox unless you really need a higher output speed than a standard NEO).

The AndyMark/Banebots planetary gearbox is sturdier than the VersaPlanetary (https://www.andymark.com/products/57-sport-options), but I don’t know by how much. Even if the 550 is only about 3/4 the power of a 775pro, 2 of them should be slightly more powerful than a NEO and 3 of them should definitely be more powerful.

Oh I had no idea Andymark’s gearbox supported 550 motors. Cool. I might make a system for their gearbox as well if I get the time. Thanks for the suggestion.

From what I’ve seen from people speculating, I think they were predicting about the power output of a minicim (maybe a bit less) and a bit less weight than a 775pro. This could definitely be wrong since it’s just speculation, but it seems like it could be accurate.

Fun fact: the 5 in “57 Sport” was short for 550. I’ll let you guess what the 7 was for.

Source: Was in the room when it got named

Also, for your knowledge in designing: The side mounting holes are on a 1" grid outside of the 4:1 (where it’s a 1/2" x 1" rectangle instead). Those holes are spaced off the output end, though.


Why wasn’t the 57 Sport not the 5Line Sport? Redline motor is AndyMark right

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  1. That’s smart. Good choice in naming. I probably should have guessed that, I just haven’t ever used Andymark gearboxes.

  2. Thanks, that’s actually really helpful. I’ll keep that in mind tomorrow when I make that. For now it’s almost 9:00 pm on a school+FRC meeting night, so I’m going to go to sleep.