Low-Friction Test Bed 1


There are few more satisfying experiences in engineering than letting your work speak for itself. Nothing can quite compare to the ability to point to your system and just say “Behold: It works!” – if a picture is worth a thousand words, a physical demonstration is worth a thousand pictures.  That’s a lot of words.

Since before the New Year, I’ve been working on such a physical demonstration of eddy-current actuator project by building an experimental test bed.  The goal is to recreate the microgravity conditions of space here in the lab.  This isn’t an easy thing to do because of inconvenient things like air (that causes drag on moving objects) and gravity (that causes friction.)

NASA has massive (70 feet by 98 feet!) air bearing floors for recreating a microgravity environment, but since that’s several times the size of the entire SSDS lab, we have to think a bit smaller.

Our solution to the problem is a heavily modified air track.  It’s like an air hockey table, but with carts that move along a track rather than a puck on a flat surface.  In addition to avoiding friction that would come with moving parts, the track constrains movement to a single dimension. Dynamics along a line allow us to eliminate many extraneous variables that would make measuring and modeling the effects of the actuator much harder.

Here’s a video of the track in action:

On the left you can see the actuator cart that will eventually use magnetic fields to control the target cart on the right.

It’s got a ways to go, but this air track test bed is an exciting addition to the SSDS toolbox.


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