I'm trying to push a lever from a linear slide. To do so, I've joined two rose joints together. the linear slide is connected to one end and the lever to the other. This allows the lever to turn in an arc about it's mounting point.

There's a problem. If I push the blue pin in the picture in the direction of the big arrow, then the coupling turn in the direction of the curved arrow. This is because spherical bearings don't resist the movement.

I don't want the bar to twist. I just want it to push. What kind of bush / bearings do I need and where can I get them?
Rescued attachment bearings.JPG

pack it up with washers?

why did you not just use a tube with two holes drilled through it?

The drawing isn't clear. The bearings aren't sliding up and down the bolt, they are bolted down firmly. The applied force is very large. Even the small fraction that is pushing the bearing down is enough to twist the rack that is doing the pushing.

I considered a solid bar with holes drilled through for the bolts. Would steel on steel wear too much?

I guess what I would like is a piece of bronze tube that pushes into a 16mm hole, say, that in turn is a nice snug fit onto the unthreadded part of an M12 bolt. I don't have a lathe to turn up such a bush.

[Edited on 7-5-2008 by smart51]

Go to a local bearing factors or engineering supply place and ask for some oilite bushes.They come in varying sizes and you could find some to fit the bolt shank and a drilled hole.
Paul.