hobbs101
Mechanical
- Aug 1, 2012
- 74
Hi. I'm developing concepts for a mechanism that I need to design. The requirements are
- move a metal block (4"x4"x8") along a circular path
- stroke angle = 11.5deg
- radius of circular path = 0.5m
- needs to be accurately positioned at any intermediate or end angle
- manual adjustment, i.e. very low speed.
- has to work in all orientations, i.e. changing gravity vector.
The problem is I can't use the centre point of the circular path as this is inaccessible. So, what I'm looking to do is use a clever design that gives me movement along a circular path in a compact envelope.
I was hoping a 4-bar linkage of some sort would be the solution, but as far as I can see this type of linkage would also give me a parasitic motion away from the virtual pivot point. This may not be an issue, but I don't think it's ideal. I'm not experienced in designing linkages, so perhaps I've got this wrong.
Another option is to use roller guides moving along angular slots. I was hoping for something more simple and elegant than this. Also, maintaining position with changing orientation is a challenge.
Perhaps a combination of linear and rotary motion might be an option? A linear slide with a coupling to a rotary mechanism?
Any thoughts on the 4-bar linkage? Any other possible solutions?
Thanks in advance for your help.
- move a metal block (4"x4"x8") along a circular path
- stroke angle = 11.5deg
- radius of circular path = 0.5m
- needs to be accurately positioned at any intermediate or end angle
- manual adjustment, i.e. very low speed.
- has to work in all orientations, i.e. changing gravity vector.
The problem is I can't use the centre point of the circular path as this is inaccessible. So, what I'm looking to do is use a clever design that gives me movement along a circular path in a compact envelope.
I was hoping a 4-bar linkage of some sort would be the solution, but as far as I can see this type of linkage would also give me a parasitic motion away from the virtual pivot point. This may not be an issue, but I don't think it's ideal. I'm not experienced in designing linkages, so perhaps I've got this wrong.
Another option is to use roller guides moving along angular slots. I was hoping for something more simple and elegant than this. Also, maintaining position with changing orientation is a challenge.
Perhaps a combination of linear and rotary motion might be an option? A linear slide with a coupling to a rotary mechanism?
Any thoughts on the 4-bar linkage? Any other possible solutions?
Thanks in advance for your help.
