[alex781]

Both look great to me. The latter looks a bit easier, maybe cheaper??? I was going to triangulate with 1 1/2 x 1 1/2 square tubing, since I have it. I might go for channel, I could use some for my lathe and justify a 6 ft length.

Alex, the cup washer is there so there is something between "loose" and "tight" for easier adjustments. It is not a locking device like a toothed or split washer. In practice, I doubt it much matters, but wave or cup washers are nice on smaller applications, like a QCTP height adjustment.

Not sure if you're suggesting building a column brace out of tubing? I guess it should be ok, the cheapest brace that appears to work is the one made by simpson36 out of 1/8" steel plate. I'm thinking it would be even cheaper and maybe stiffer to use two pieces of steel Angle, either side of the column nut. One would have to remove the cup washer (thx for the correct term!) but hopefully as you say it has no locking function anyway.

Did a 5 minute mockup in paintbrush

[knudsen]

With the square tubing, I would triangulate out the side, bolting the outriggers to the steel under the bench.