# Moving a Bushing in Circular Motion

I am trying to design some way of making a bushing move in a circle. Specifically, I want the center of the bushing to draw out a trajectory that is a 3" diameter circle. I do not want the bushing to rotate. Any ideas/mechanisms for how to do this? I may just be overthinking it. I cannot have a pivot in the middle of the bushing as I have something passing through it.

I question why you do not want the bushing to rotate relative to the thing passing through it because if there's no relative motion then there's no point for the bushing.

You're going to need more detail. Because based on what you little wrote inserting the bushing into a off-center circular slot on a rotating disc would be acceptable. Sure the thing passing through the bushing might rotate relative to the thing passing through the bushing but if it doesn't then a bushing is pointless to begin with. If there's no relative motion then there's no point to the bushing.

If you want to move the relative motion away from the inside of the bushing to somewhere else then use a ball or roller bearing instead of a bushing. If a ball bearing won't work because the thing passing through the bushing is sliding axially then we're back to the fact you already have some relative motion in the bushing so what's the point of preventing it from having some rotational relative motion?

EDIT:

To move a bushing like that, same basic idea I mentioned above about mounting the bushing in an off center hole in a spinning disc. You can just put bushing into a panel with four holes in the corner and mount the for holes off-center into four discs and then rotate the discs. I don't think you need to drive all the discs but you need to drive at least two. The remainder can just guide and support

Or you can just mount the entire panel on an X-Y gantry and have software trace out a circle for you. Or whatever else you want for that matter.

I stand by what I said about not needing to see why you need to prevent rotation between sheath and the bushing. The bushing is there to deal with the relative motion between the panel and the sheath. If you're worried about fraying the sheath then use a ball bearing and secure the sheath to the inner race. That moves the relative motion away from the sheath and bushing to the ball bearings and and the races

• Want something like this: youtube.com/watch?v=VTkULChFXkk Jan 25 at 20:57
• See edits....... Jan 25 at 21:06
• Why do I need the panel like plate with four holes? Is there any benefit to that instead of just having one spinning disk driven by a motor and then putting a bushing off center? Jan 25 at 21:19
• @GeorgijeStanisic It depends whether you need the point the bushing is orbiting around to be clear or not. The plate has everything to the side. The disc has everything right at the center. Jan 25 at 21:29

You can use a mechanism like a bicycle pedal. Connect your bushing where normally the pedal is mounted.

Either have it turned by the chain as in a bike or a servo.

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