Wood or metal, just be sure the thing is very strong,, and heavy.
Far as the top goes,, i,d want nothing other than a formed up sheet metal top, worth buying a sheet and getting the sides bent up in a brake, makes a nice top, very easy to clean up , especially oils, and chips etc.
Good description, Turbo. I have done that sort of thing for heavy loads. The elevator bolts aren't available over 3/8" as I recall, so they work well for smaller projects. Tee nuts can be fitted into the ends of the legs and then a jam nut snugged up against them to lock the leg in place.
I have my surface plate leveled with something like these:
There are rubber skid pads on the bottom. I have some in 5/8-11 that are delrin footed. When I finish rebuilding my compressor, they will go there.
You're absolutely right. You can't buy that satisfaction.
Those feet are about $13.00 each. I can't make them for that, to be sure.
I wonder if, on yours, you'd benefit by putting some isolation damping material under the feet, between the 4 x 6" and the concrete. Some scrap big rig mud flap material is very tough and would give a little and reduce vibratory noise. Just keep your eyes open on the road to find one that has fallen off a truck. Happens all the time.
I'm thinking that you may find a resonating rumble or droning just from the motor. It always seems to work out that way for me, and I try to get rubber under feet, especially if they are large, like your 4 x 6's will be. I'd definitely do it, were it mine.
It would be easy enough to come back later and do, if you needed it.
Maybe it's a Canadian thing but we tend to use hockey pucks for noise and vibration damping. They can be machined to fit the feet so they don't slide and drilled to accept a through bolt. Had them under my 80gal 5hp compressor for over 20 yrs.
I have them under a variety of machines, compressor, Press, workbench, pedestal grinder and they were used on my old lathe.
Easy to make, drill through 1/2" diameter and Counterbore 1-1/8" by 3/8" deep
Cut a 1/4" thick washer 3" diam. I use a 3-1/4" holesaw, drill out the pilot hole to 1/2" and mount on a mandrel and turn to 3" diam.
Use a 1/2" carriage bolt about 3" long and a few nuts and washers and you are ready to go.
No, Melamine is not Formica. You will see this type material in some bathrooms as walls (over drywall). It's water resistant and pretty hardy. It's not as hard or slick as Formica...should make a great top.
I like 1/4" Quench & Tempered hardboard for workbench tops, glued down with contact cement. Mine needs redoing soon, but has stood up to all sorts of abuse for better than 20 years including being stored outside for awhile.
My lathe tables I like a metal top. Or at least a chip pan made of metal, large cookie sheets work well. My current lathe has a deep metal drawer that acts as a chip catcher, well at least some of the chips, the rest end up in my hair and all over the shop.
Now speaking of all over the shop, got a fly cutter set for the mill not long ago, first time I used it, I had chips coming out like casings from a machine gun. I am still picking short curly chips from dark corners of the shop.