4" Brass Flywheels for Sale from SDS

I’m excited to announce that we have 4" brass flywheels for sale. They increase the moment of inertia of your shooter. The flywheels would typically be used beside 4" shooter wheels. For reference, below is a photo of 2910’s 2020 shooter.


Not complaining my any means, but why brass?

It’s easy to machine and quite dense.


These look absolutely beautiful! $75 seems a little hard to swallow but I have no idea what other flywheels sell for and if there are even any others on the market.

But still, these look really good!

EDIT: is this for just 1?

Why did you choose the triangular cutout in the middle instead of a broach/something like VersaKeys for a VersaHub?

I’m pretty sure because it’s easier to machine.


That makes sense. I literally wrote the reply and then answered myself after giving it a second thought :sweat_smile:

Thanks! The price is for just one flywheel. The high price is due to the brass stock being quite expensive. In my experience it is 4 to 5 times the price of aluminum.


Can confirm. When we made brass flywheels in 2017, a 6" dia., 1/2" thick brass disc was about $85 from McMaster. That’s with the McMaster markup, of course, but still.

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That makes sense, thanks for the info. I can’t wait to see what else you guys come up with!

Those look amazing! Do they come off the CNC looking like that or did you do post polishing?


From mcmaster, A puck of Brass to make this flywheel is $80. Thankfully there are less expensive sources.

Thanks Andrew! They come off of the Mill looking like that.

We originally designed our flywheel this year to be made from brass, but chose to switch it to stainless steel in large part because of the price. Just as an example, a 12" long 4" diam. round brass rod is $400, whereas an equivalent 304 SS rod is $227. Their densities are just about equal (46.3 lbs vs 43.3 lbs). The real reason to use brass over SS is machinability, but we were machining them on our aeronautics sponsor’s industrial lathe so that wasn’t really an issue.



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Don’t get me wrong, I love the look of brass or SS…

But from a practical standpoint, 12L14 would be the superior option in terms of price and machinability. Not as much as brass but way, way better than any SS.

https://www.midweststeelsupply.com/store/12l14coldrolledroundbar <- $100 for a 12" long 4" diameter bar.

Yes, it easily rusts. But it also cold blues extremely easily.

I’d also say (and probably not the case for some teams), that for something like this, it rusting isn’t all that big a deal to us. This is something that by this time next year will probably be in a scrap bin (well, maybe not at the current price point :wink: ). While i’d love for all our robots to stay together and functioning, it’s just not feasible for many teams. So personally I’d love to see something a bit less expensive, while not so pretty :slightly_smiling_face: .

Either way though, huge fan of this new product development, and so early into the off-season too :sweat_smile:

Somebody is enjoying their new Brother Speedio at home eh? Nice work.


You’re using fat angry triangles spinning 9krpm the wrong way.


Heh… Wankel.