Basically you just drill a hole in the square hole on a lock bar to make it.
It considerably skinnier and should make axle joints more viable. It has roughly the same amount of slop normal bearings have and have way less friction. Due to it being metal instead of plastic.
I don’t really see any cons of it but if there are any please tell me.
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The thinner size would put more stress in one area and would create a line on the axle and would weaken it.
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True but if it’s supported on 2 sides of the axle this shouldn’t be a problem because the axles are made of steel and I don’t see how it would be damaged from being hit by the lock bar.
normal bearing are definitely better than this. metal on metal contact has more friction than metal on plastic, the lock bar is very skinny compared to a bearing so it will have much more slop, also it’s very difficult to perfectly drill that hole, and if you don’t do it perfectly there will be friction or slop on the axle. also like @ean said, over time the lock bar will eat away at the axle which isn’t good. The only time I can see this being good is if you have no space for normal bearings, and don’t care about friction or slop that much.
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Your drilling an attachment hole for the screw not the one the shaft goes through and the hole is perfect for an axle.
oh yeah forgot what lock bars holes look like for a minute. but all my other points still stand.
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I probably wouldn’t use this type of bering on my drive because that is where the axle will rotate a lot and that will cause a lot of wear on the axle. But using on other areas might not be very bad if someone doesn’t have space.
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While metal to metal has more friction the surface area touching an axle is much smaller
I don’t think that will compensate for the extra friction metal on metal creates
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https://www.tribology-abc.com/abc/cof.htm
Here are some numbers for the friction and the lock bars are 0.05 in wide compared to the 0.25 in of a normal bearing. So the normal bearing has 5 times the surface area touching the shaft.
but the smaller area means the shaft will be pushing harder on that smaller area than it would spread out over the larger area of the bearing.
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Probably the only down side and maybe use a combination of a normal one and a lock bar on the drivetrain and if it’s a shaft without wheels you could probably just use lock bars.
So many people on the discord and the forums really love pushing ideas to the grave. But I have to be honest that its not even suprising anymore, and for that reason I want you @9935E to know to ignore quite a lot of these opinions and understand its potential. Your idea is quite interesting, I did something like that on my VEX ITZ robot’s translation mechanism:
You probably can’t see it, but I utilized such an item to hold the 12 tooth gear as a low profile bearing flat on the translation gearbox on the left side of the robot. Friction was so little it allowed my translation mechanism to work with only one motor, which allowed me to make finals in South Texas States and make it to the VEX World Championship back in 2018. Your idea about that has extreme potential as something that is almost frictionless and low profile, allowing you to add compact gearboxes and make advanced mechanisms (provided that they don’t require too much torque).
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This is terrifying
If you want smaller bearings use green insert bearings. Theyre even smaller than this design and they’re plastic so they have a significantly less CoF
edit: here’s a pic of what I mean. You have two ways to make them- drill and file a square hole in c channel and push the inserts in, or sand/file the inserts themselves to fit snug in the c channel holes. I recommend the second option. Do note that these bearings should be drilled out, just to ensure their ID is the same. Vex has poor tolerances on these. But after that is done, you will have very nice compact and reusable bearings.
(Posted wrong pics first time cuz I’m on mobile oops lol)
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Ethan have you even tested it in real life or just speculation. When I can I’m going to post my results of spinning a shaft with the lock bar for as long as a battery/motors doesn’t burn out. With weights on the shaft to see if it messes up the lock bar.
I have. Ive played around with a lot of parts like this. I’ve been searching for better bearings for a long time now and I can tell you this is not a good solution. Just being honest
the green insert bearing are definitely better. less friction, less slop, and just as low profile. I would use these if you need a low profile bearing.
This only would happen if you apply enough stress, but if we’re talking about a compact and low-profile mechanism that isn’t as reliant on torque, I would have to say that this mechanism would be perfect.
This depends. My VEX Turning Point robot had more friction with the HS bearing flats, so I took them off and used metal which worked pretty well at intaking multiple balls with a 600 RPM motor. Now, it probably has slightly more friction than a drilled out HS bearing flat, but I needed the low profile to keep the robot small and nimble:
Metal on metal is frowned upon, but in the right context, it can work very well if torque isn’t as much of a necessity and low-profile is a necessity.
I do agree that mechanism would work very well, but there are certain times where I would rather risk a bit of friction than risking the insert from falling out mid-match. There are benefits and drawbacks to either design, but it’s purely up to the context as to what would work better or for worse.
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That’s really good for putting in a spot without a motor but if you need a shaft connected to a motor you should probably use the lock bar since you don’t won’t the shaft misaligned with the motor. Also it’s roughly the same size.
Seems that the drawbacks are pretty stacked on the metal on metal bearing side