A Workshop Luxury- Build

[William Fretwell]

Mark, you need three points to level something; such as an accurate balance or my commercial laser level. All the commercial granite plates are flat by design but not necessarily level! They all have a metal frame with four legs, level is not a requirement. I do agree the fifth leg is a royal pain and agree with Brian it will just pull the other legs off the floor. I considered bolting it to a concrete plate with a spacer in the middle to provide leverage as an attempt to flatten it.

I may have solved my problem however. It may get sold to a local pharmacy as a balance table for their new compounding room. The mass of the granite counteracts room vibrations for accurate weighing. The fifth leg is gone and the drawer back! Money raised should cover a Kijiji listed commercial granite plate!

[Mark Hennebury]

You need three Points to support a Flat surface without distorting it. The three points of the triangle are placed to evenly distribute the weight. The base may have four legs. But the tops is supported on three points on the base. Four legs placed at the corners will not properly support the load, and would need to be individually adjusted to carry the same weight, and still won't properly support the weight.

[David Carroll]

You need three Points to support a Flat surface without distorting it. The three points of the triangle are placed to evenly distribute the weight. The base may have four legs. But the tops is supported on three points on the base. Four legs placed at the corners will not properly support the load, and would need to be individually adjusted to carry the same weight, and still won't properly support the weight.

We have a huge granite surface plate here in our machine shop. I think it's 2-feet x 3-feet x 4-inches thick and weighs a lot. It was purchased on a welded stand that I needed to cut down shorter so it wasn't taller than our benches. Just as you say when I took the stone off of the base (no easy task) it was supported by a triad of metal pads welded to the top of the stand. Very Cool.

DC

[William Fretwell]

Most interesting! It does make sense for such a weight. Have to calculate where the three supports would go.....
Even a small triangle would not solve my dip problem!

[Will Blick]

I too have a desire for a large FLAT surface.
for flattening long plane bottoms, wouldn't a long piece of float glass be more ideal? such as 14" x 36" ? not so heavy, maybe 1" thick I would guess.
Easier to store, so won't take up so much floor space.
Who makes this glass? Looked around for it once, but no luck... any ideas?

[William Fretwell]

Will, float glass will only be fairly flat but the sheet will bend also. I doubt very much it would be truly flat even on what you consider a flat surface (which won’t really be flat). The machined casting on one side of my table saw is probably the flattest surface in my shop but not even close to machine shop granite flat.

[William Fretwell]

Progress report:
Scribed the stretchers rotating them end over end so same side does not flip.
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Then used a large tenon saw to cut down. The right side cuts gave me more trouble than the left.
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Had to finish the cut with a bow saw:
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Clean up with a large chisel and/or Lee Valley large shoulder plane. Then the shoulder was tuned with the shoulder plane.
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Next step the mortices.
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Rotate! It will not!