NEO and Spark MAX questions

I ordered some NEOs and Spark MAXes earlier this week when the MAXes came in stock at REV, and I have a few questions/concerns as I try to get the first one set up.

NEO: I found that the shaft was slightly oversize and the keyway was slightly undersize compared to CIM and mini-CIM. I am mounting this into an AndyMark toughbox series* gearmotor. I have always been able to install keyways and pinions by hand, and only needed a tool (usually a nutdriver) to push the retainer clip in place for both CIMs and mini-CIMs with about 5-10# of push. With the NEO, I had to use slip-joint pliers to get a 2mm key from AndyMark into the keyway. LIkewise, the AM 14t pinion did not push onto the shaft with fingertip force. While I did not need an arbor press or even a vise, I found it necessary to mount the motor to a gearbox motor plate, set that in a workbench/vise, and push down with about 30-50# of force, using a nutdriver - significantly more difficult than putting a 14t pinion on a CIM or miniCIM. Is this normal, or do I somehow have a “swollen” NEO shaft? Should I have taken the “can” off to do a press fit at this amount of force, as required for the smaller pinions used by the latest generation gearboxes?

OK, also a MAX question. Where is the heat sink? Placing a finger on various spots on the outside of the (never used) controller, the black patch on top with the words REV ROBOTICS SPARK MAX is the only place which feels cool. Is this the heat sink area?

* Specifically, a TB 3-motor gearbox, one of the ones with a 1/4" aluminum motor plate, though I doubt that this matters here.

I had no issues installing keys or 10t and 11t pinions on the NEOs we preordered before the season and haven’t heard anything else except keyways occasionally being tight, but that seemed to happen with CIMs as well. You may just have a wonky batch (or possibly some undersized pinions); do you happen to have any mic’d measurements?
And yes, the heatsink is under the black area with the logo. It’s detailed in the CAD model.

We used the 32DP 15 tooth pinion on the NEO drive motors this past season.
Definitely had to take the can off to press those pinions on.
We had a couple that used keys. These were on custom gearboxes, but I don’t recall anything special in assembling.

We Ty-Raped the SparkMAXes (10 ea,) to aluminum gusset panels.
Electronics operated cool enough not to be the problems we needed to work on!

I’m fairly certain I watched one of our students easily mount/remove a couple NEOs from Toughbox Minis entirely by hand (and nutdriver) when we were debugging a mis-behaving motor (It had been mis-wired…)

The heat sink for the SPARK MAX is the black aluminum base. The logo is just pad printed to the top plastic case and isn’t in contact with the heat generating components.

The original SPARK had the logo etched on the aluminum heat sink.

Feel free to take some measurements and send us an email at

Whoops, got mixed up there. I was looking at a over driving the OG Sparks the other day and figured the heatsink would need to be modified. I kind of miss the aesthetic tbh.

I noticed while putting keys in neos this year that they were a little tight. I placed them on the groove and pressed them in with some pliers. I think we used 12t pinions and they slid on perfectly fine.

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I had the same experience with the NEO and KOP gearboxes.

We’ve also had similar experiences with the keys on NEOs, most of them needed a bit of elbow grease to go in, some went in a lot easier then others.