When Thriftybot first came out with Thunderhex bushings, the idea seemed pretty great. It was demonstrated to work at up to 3000 RPM, and even Vex has since made their own, similar product. Despite all this, i have yet to see or hear of them being used on competition robots.
What are some good examples of bushings- and more specifically Thunderhex bushings- in FRC robots? If you have any good examples, post them in this thread.
Absolutely Nothin’ (HUH)
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That being said, I know we ended up using them on smaller dimension, low-velocity “a bit of friction ok” intake linkage joints, and in some elevator parts. But I’m far from an authority on “bushings, good or bad?”.
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This year, all of the axles on the transfer between our intake and shooter were bushings. We machined a sheet of them on our router to fit the point to point on a piece of 3/8 hex.
We did this mostly so we could put a bushing in a piece of 1x1 tube as well as to cut down on weight. Overall we had no complaints with this approach.
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Technically they are not bushings they are bearings. Just not roller bearings.
We use the bronze and plastic bearings where we need a smaller package. They work great.
Swerve azimuths. (Runs, ducking for cover)
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They’re quite a bit lighter, so I’d say they’re good for weight savings.
I’ve used bronze bushings on shoulder bolts and 7075 aluminum or anodized aluminum tubes or shafts for low speed rotating joints and it has worked out okay.
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Turret.
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Bushings are good for low-velocity interfaces where you don’t want the complexity and weight of a roller bearing or ball bearing. Pivot points for arms are a good example of a place where a bushing is often an appropriate solution.
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They’re good where a roller bearing might experience an impact load capable of deforming the balls or races (single jointed arm comes to mind). Plain bearings can be damaged in the same scenario, but the failure mode is much less disastrous.
That said 1/2" hex bearings are so overkill for almost everything in FRC, the smaller footprint bushings are probably best for space savings, followed shortly by weight savings.
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We used them on the pivots of our 4-bar mechanism a few years ago.
After the 2022 season, we’ll never make a pivot on an FRC robot without a bushing again. They are cheap, come in a variety of sizes, and work great.
We used oil embedded bushings in 3 ways:
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Intake pivots
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Climber pivots
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2 Position pnuematic hood pivots
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What’s the best way to keep them from falling out?
I’m starting to incorporate more bushings into my designs. Typically we throw bearings everywhere, but I know that 50% of the time it’s not necessary
Probably similar to the methods in this thread.
Now I want to find one of my pictures of a 80,000-100,0000 pound capacity bushing 
Fraction pump bearings and gears, enhanced with extra rust…
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That is fed with oil pressure, wouldn’t that technically be a fluid bearing?
Stop being so technical, Mark. Oh, wait …
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To build off some of the responses in the thread - bushings are great for relatively-low-load and relatively-low-RPM tasks on your robot. They save space, weight, and cost compared to roller bearings in these applications. While you may want the full-RPM rating of a roller bearing for your initial intake-wheels that gather a game piece outside of your robot, lower RPM feed and indexing shafts could often be run off of bushings. Pivot-joints for things like intakes or small manipulator arms can easily be bushings.
The smaller size of bushings leads to compounding advantages when it comes to packaging and weight. If a team primarily uses aluminum box tubing to build from (like VersaFrame), a bushing allows them to place their rotation point in a 1"x1" tube, rather than needing the wide face of 2x1 or an additional gusset to hold the 1.125" outer race of a 1/2" hex roller bearing. That saves on not only the weight and space of the bearing, but also on all the mounting hardware required.
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Would you say bushings used on 1/2 hex for climbing be considered a high load?