While it's not apparatus it is an idea for a utility.

As some of you might know, on the day after Christmas of '07 my wife were plowed into by a drunk driver. Both of us got walkers out of the whole mess. Well, during cleaning for this past Christmas, mine resurfaced. As I looked at it the ides struck me that it could be made into a performing table. It's light weight and flattens nicely.

Right now I am experimenting with different size tops as there is a stability issue as the top gets wider so I may need to figure out some kind of bracing depending on the size top I settle on.

Will keep you posted on my progress.

The electrical area in your hardware store will have anchor clips for EMT tubing (conduit)... A few of these with a wing nut may make a good clip to attach the top surface securely. They also have some hammer in types that I have used to hold conduit pipes in place for cart axles, anchoring a larger pipe through which a smaller pipe passes.