Name of arm that moves in vertical plane?

[swwrobotics]

Hey everyone,

Does anyone know of an arm device that rotates on a single point, yet unlike a four-bar mechanism, the end of the arm will stay in the same vertical plane? I know a vex team did this in 2010 with picking up the inner tubes and I thought the device was really cool. I can sort of visualize how it works, but all I remember was there was a sort of "scissor lift" mechanism on the end.

Thanks

[Christopher149]

Can you sketch it out? Your description is a bit confusing to me, since it sounds like that's what a four-bar (parallelogram) linkage does.

[Mike Marandola]

Originally Posted by swwrobotics

Hey everyone,

Does anyone know of an arm device that rotates on a single point, yet unlike a four-bar mechanism, the end of the arm will stay in the same vertical plane? I know a vex team did this in 2010 with picking up the inner tubes and I thought the device was really cool. I can sort of visualize how it works, but all I remember was there was a sort of "scissor lift" mechanism on the end.

Thanks

I am not quite sure what you mean by "stay in the same vertical plane". Does a four bar linkage not keep the game piece in the same orientation/vertical plane? Could you clarify?

[swwrobotics]

This is a very crude sketch but it is everything I can remember. I think there might have been two fixed points on the joint mechanism, which is what the green dots represent. The red line shows that the end point of the arm always stays in the same vertical plane. A four-bar mechanism will not do this as it makes an "arc" as it is raised from the lowest to highest point.

[AGPapa]

It's a Peaucellier-Lipkin linkage.

[swwrobotics]

Originally Posted by AGPapa

It's a Peaucellier-Lipkin linkage.

Ah! Thank you!!!!

[asid61]

This guy has a bunch of videos on this:
https://www.youtube.com/watch?v=4xGNB2jlcVk
I think stuff like that is what you're looking for?

[kmusa]

And for a different perspective, there are the models that demonstrated the theories of Franz Reuleaux - link - 39 of which are straight (or almost straight) line motion.

-Karlis

[Joseph Smith]

https://www.youtube.com/watch?v=ioilEy1I8lY