alexy wrote:

My question is really about modifying store-bought furniture, but is
just as applicable to a chair I might make.

I have a bar stool with turned and slightly splayed legs. The bottoms
of the legs are cut perpendicular to the axis of the leg rather than
on the plane of the floor. I'm thinking of putting it on my bench,
and using a pencil or plane iron bevel-side down to mark a uniform
distance up from the bench, then suing a block plane to trim these leg
ends to be coplanar. And reason not to do that?

Willing to bet a considerable amount you won't get it done to
anybody's satisfaction.

snip

Any other ideas? (The floor is already
down, so mag-lev is probably not feasibleg)

You take a page from the Gougeon Bros book on Boat Construction
Mounting sheet winches. (they almost always get mounted at some goofy
angle).

Basically, you screw a sheet metal screw into the bottom of the leg
leaving say 1" exposed.

Set chair of floor and adjust screws till chair is level.

Apply epoxy fairing putty around screws in 2-3 applications, 8-12
hours apart.

When finished, allow to cure for about a week, remove screws and sand
smooth.

Attach new floor glide to bottom of fairing putty.

Couple of things to remember:

1) The above adds about 1" to 1-1/4" to leg length, may have to trim
leg before starting.

2) Fairing putty is white. Either tint during or paint afterwards.

Paint is easier.

Have fun.

BTW, all of the above assumes the floor is level.

Lew