How can I create a mechanism for precise linear motion in two planes?

[Irish_]

Hey guys, I'm brainstorming some ideas for a mechanism that will be able to move an object in the vertical plane up and down, as well as left to right. Essentially I'm looking at controlling the X and Y coordinates of this moving mass. I want to be able to move in the vertical plane, lock it into place, then move in the horizontal plane and lock that position into place as well. To bring it to scale I'm talking about moving the mass at most an inch up/down as well as an inch left/right.

If there already is said object and I'm just not seeing it available, please feel free to point me in the right direction. I guess it would be easier to just buy the mechanism rather than manufacture it.

I was originally thinking of the idea of using 2 parallel tracks which works great in one plane, but makes it rather difficult when trying to change the other displacement.

Any feedback is greatly appreciated guys, thanks again!

 

[Mech_Engineer]

How much weight, and how big?

Edit: and what resolution?

 

[Irish_]

The actual mass is around 1 to 2 lbs-force, but this may be submerged in oil so it will have some buoyancy force. It's a cylindrical shape with 1.25 inch height and .75 inch diameter. Not sure on what you mean by resolution?

 

[berkeman]

The actual mass is around 1 to 2 lbs-force, but this may be submerged in oil so it will have some buoyancy force. It's a cylindrical shape with 1.25 inch height and .75 inch diameter. Not sure on what you mean by resolution?

He means, to what resolution do you need the movement/position to be accurate. Like, milimeter accuracy? Or micrometer accuracy?

 

[Irish_]

Ahh, to the millimeter would be great. If we could go to the tenths of millimeter that'd be even better and more desired.

 

[Mech_Engineer]

How about a pair of these mounted together with a right-angle bracket, they will get you 25 micron resolution pretty easily I think (the micrometer is actually less than 1 micron sensitivity).

http://search.newport.com/?q=*&x2=sku&q2=443

You can also replace the micrometer with a locking adjustment screw like either of these:

0.7 micron sensitivity (100 TPI): http://search.newport.com/?q=*&x2=sku&q2=AJS100-2
4.0 micron sensitivity (20 TPI): http://search.newport.com/?q=*&x2=sku&q2=AJS20-2

 

[Mech_Engineer]

Here's a nice off-the-shelf 2" XYZ stage from Thorlabs:

http://www.thorlabs.com/thorProduct.cfm?partNumber=LT3
http://www.thorlabs.com/thorProduct.cfm?partNumber=LT1

 

[Irish_]

thanks for the help guys, I probably should have mentioned that this will be immersed for the most part in oil also size of the mechanism needs to be as small as possible.

 

[Mech_Engineer]

I think either of the two options I gave you would work ok immersed in oil, but of course you could have them outside the tank with an arm that reaches in. There's no way for us to help you get any smaller than these without knowing something more about the geometry and the tank of oil it's going in. For 2" travel those are pretty compact IMO.

Remember that each of those is an off-the-shelf option that you can buy and you're done. Sure engineering your own exotic solution is possible; but it will end up more expensive, harder to document and support, and unless you're a precision motion engineer might not work as well.

 

[Irish_]

Exactly, I agree. Off the shelf is a best bet. Thanks for the input. I will continue to brainstorm ideas, I like the linkage arm idea outside the tank reaching in. This device will be working with a magnetorheological fluid application.