Building .25” steel tables for a Ras

[Bobby Robbinett]

I guess this could be more of a metal working question. But it is for my Dewalt GE ras so I would like to get some input from you guys.

I want to build a couple of 8ft x 24” extension tables for my RAS that are similar to the Original Saw Company’s tables they sell for their RAS’s. I want to build it out of 1/4” steel for the top with a 20” wide x 30” tall set of industrial legs for the far ends with the other ends mounted to the saw on some angle iron.

I am curious to know from some of you guys how I could insure that the 1/4” steel top is flat? Would I need to find someone, perhaps a machine shop, with a large hydronic press? Could it be pressed flat? I don’t want the expense of having it machined. I was quote $1,900 for having it machined flat. Any suggestions?

[Carroll Courtney]

I had a similar setup years ago, but for me I didn’t use it that much to take up all that space. I had some cabinets mounted along wall above but it was challenge to reach. To me RAS are not that accurate to justify tables of that caliber. I seen another guys setup where he was using roller tables for his in/out feed, it was neat. Made it easy sliding plywood. But, we all have our own ideas, so go for it make it work for you.

[Richard Coers]

First off that piece of steel will weigh 163 pounds. The flatness will be established by the structure under it, not the slab itself. That piece of steel can sag over the length just from the weight of the steel itself. The hydraulic press would be to straighten the welded steel stucture under the top. If you have done much steel fabrication, you should know that simply welding all the parts together will draw any structure out of flat. It would have to be welded on a large bed plate or super heavy welding table. If I wanted a structure like that I would build a wood torsion box for the top and structure under it resembling a workbench.

[Bobby Robbinett]

First off that piece of steel will weigh 163 pounds. The flatness will be established by the structure under it, not the slab itself. That piece of steel can sag over the length just from the weight of the steel itself. The hydraulic press would be to straighten the welded steel stucture under the top. If you have done much steel fabrication, you should know that simply welding all the parts together will draw any structure out of flat. It would have to be welded on a large bed plate or super heavy welding table. If I wanted a structure like that I would build a wood torsion box for the top and structure under it resembling a workbench.

No welding will be done. Might make a frame out of aluminum extrusion though. Every thing will bolt together. I suppose I could also use a slab of quartz. My local shop would sell me one for a deal

[Jim Becker]

Bobby, regardless of the material you choose, you'll need structure to support it as Richard correctly points out. Steel, cast iron, stone, wood, whatever...it all can sag, albeit at different rates.

[Bill Dufour]

Stone slab is a poor idea. I did it for my outdoor RAS with marble. Threw a heavy timber on it and cracked it. But it was not on. plywood just supported by outer edges and some i n the middle parts.
Design the table so feet are adjustable and top sits on bolt heads to flatten the metal.
Bill D

[Richard Coers]

I had no idea you would try to build it with just the legs and the angle iron alone. You'd have to use something like 1" thick steel if you didn't want any sag, and even then I wouldn't guarantee that. What's wrong with melamine or plywood?

[Robert M Richardson]

How "flat" do you want it to turn out? I made three work benches for our shop out of 1/4" hot rolled plate with 1/4" x 2" stiffeners welded perpendicular to the undersides. I never checked for flatness but I could do that if it would be helpful. Speaking from experience I'd be surprised if a piece of 1/4" HRP could be machined flat period. Too many residual stresses from the rolling process, every cut will relieve some stress and the plate will move, at least that's been my personal experience.
Robert

[John TenEyck]

My RAS bench is 8 ft long, two pieces of particle board glued together, with a Masonite top, sitting on top of cabinets. It has stayed flat for 30 years. If I wanted to make extensions I would do as Richard said and use torsion boxes. Easy to make, light, and they will be and stay flat as long as they are when the glue dries. I don't see any benefit of steel, but if you want a steel top surface, then glue or screw a piece of 16 gage stainless to the top of the torsion box.

John

[Bradley Gray]

My RAS bench is 12 ft on each side, made of 2x4's with double 3/4" ply top. It has been flat 40 years despite having big timbers plopped on it and other abuse. Why metal?

[Bobby Robbinett]

I had no idea you would try to build it with just the legs and the angle iron alone. You'd have to use something like 1" thick steel if you didn't want any sag, and even then I wouldn't guarantee that. What's wrong with melamine or plywood?

Richard I should have mentioned in the first post that I never intended on building it with out a frame under it. As I posted yesterday the frame will be made of aluminum extrusion with an industrial leg on one side and a piece of angle mounted to the saw on slotted holes on the other side. That way I can adjust the flatness relative to the table on the saw end, and use leveling feet on the other. This will all be bolt together. No welding. Including the 1.5” x 3” aluminum extrusion frame

[Richard Coers]

Richard I should have mentioned in the first post that I never intended on building it with out a frame under it. As I posted yesterday the frame will be made of aluminum extrusion with an industrial leg on one side and a piece of angle mounted to the saw on slotted holes on the other side. That way I can adjust the flatness relative to the table on the saw end, and use leveling feet on the other. This will all be bolt together. No welding. Including the 1.5” x 3” aluminum extrusion frame

You've priced the aluminum extrusion? That stuff got really expensive like everything else. It's sure out of my price range for letting a board lay on it while the trim the other end!

[Tom Bender]

How about making the frame out of double unistrut? It's pretty strong and is easy to bolt to. And you can add shims if needed to flatten the top.

Then you can hang drawers underneath.