Custom bushings

[Gdeaver]

I've used 2 tapered roller bearing for turntables before. You could probably go down to 3/4" shaft size. Weight I assume is not an issue.

[David Guzman]

A great material for bushings is UHMW (Ultra High Molecular Weight Polyethylene).

We used this extensively, not only on the robot but at work for many bearing applications. It is very easy to machine, has a very low coefficient of friction and can withstand significant loads for a plastic.

You can get rods from McMaster fairly cheap.

[jman4747]

Originally Posted by David Guzman

A great material for bushings is UHMW (Ultra High Molecular Weight Polyethylene).

We used this extensively, not only on the robot but at work for many bearing applications. It is very easy to machine, has a very low coefficient of friction and can withstand significant loads for a plastic.

You can get rods from McMaster fairly cheap.

I would say +1 to UHMW, Delrin (Acetal Resin), or Nylon 6. All inexpensive all great bearing surfaces.

Another thing to consider if you can wait I would research different suppliers, Mc Master Carr is the fastest and arguably the best but not always the cheapest.

PS "All inexpensive" is a relative statement.

[asid61]

The thing is, the bushing looks pretty strange, and I can't really change the design at this stage (it follows an ultra-space-saving design that requires its weirdness). Basically I changed the design so it can use a smaller bearing, which is like 7/8" inner diameter and 1.125" outer diameter. However, it has a very large flange that's around 2" outer diameter. I'll look into using plastics for machining and cost without sacrificing strength. I've used UHMW in the past, but we tend to have a lot of acetal so I'll try that on aluminum too.

[highlander]

Originally Posted by asid61

The thing is, the bushing looks pretty strange, and I can't really change the design at this stage (it follows an ultra-space-saving design that requires its weirdness). Basically I changed the design so it can use a smaller bearing, which is like 7/8" inner diameter and 1.125" outer diameter. However, it has a very large flange that's around 2" outer diameter. I'll look into using plastics for machining and cost without sacrificing strength. I've used UHMW in the past, but we tend to have a lot of acetal so I'll try that on aluminum too.

In my experience Delrin machines really easily, while UHMW has a much lower coefficient of friction. However, UHMW is annoying to machine.