The only improvement I can think to suggest at the moment is adapting the design to use cage nuts. I imagine this would be straightforward given that you are using 10-32 screws.

I'm interested to know just where and how you envisioned the use of cage nuts on my gadget?

I was thinking of putting square holes in the bars and plate, into which cage nuts could be installed, where the existing holes are. This would provide some insurance against threads stripping at any point the lap bar's life since the offending thread could be replaced easily (with a new cage nut).

Of course, I could be off base.

Thanx for the input but so far things are working real well with just threading the holes in the body block w/a tap and calling it good.There's just not that much stress or weight bearing going on - mainly because it's a hunk of aluminum bolted to a hunk of plastic on an expensive instrument that's always handled very carefully (I would hope). Anyhow it's an "install it, and leave it installed" kinda gadget that in most cases will be installed/removed from the instrument very few times in it's lifetime. If somehow I needed more strength or started seeing soft metal galling or crossthreading in a device of this nature,I'd prolly just put steel heli-coils in there before I would deal with the hassle of milling or broaching square holes.

BTW, if I go to the NAMM show this year I'll try to bring one by the Stick booth so whoever wants to can check it out.

That is a very good idea.

I come from a tradition of overbuilding things (my father's cabinetry was often called "boat building" by fellow woodworkers), and that is somewhat aggravated by my spasticity (I can strip threads just by looking at them, it seems).