Replies

1. 
   highfigh | Jan 27, 2007 10:35pm | #1

   Look for information on 'torsion box' here and elsewhere online. David Marks made an assembly table on his show a while back and it's basically a pair of flat surfaces (he used MDF) with a series of pieces glued/stapled parallel to the sides and ends. You can think of it as a floor system and a sheet of MDF glued and stapled to the bottom of the joists, with blocking glued and stapled between all of the joists. How stiff it needs to be will be determined by the amount of weight you expect to put on it.

   This needs to be assembled on a really flat surface, for obvious reasons. Once the glue is dry, it won't flex much at all. It doesn't need to be very deep, either. 4" should work. Attach stringers and legs underneath and it should last years. A couple of coats of poly should do to keep it from swelling.

   "I cut this piece four times and it's still too short."
1. 
   colebearanimals | Jan 28, 2007 06:36am | #3

   Thanks for your imput,

                  Paul

2. 
   colebearanimals | Jan 28, 2007 06:49am | #4

   highfigh,

        Who is David Marks and what is his show?

                            Paul

    

   p s   highfigh............ever used tub electronics?

1. 
   highfigh | Jan 28, 2007 06:59am | #5

   He had a show on DIY Network called 'Wood Works'. They still show repeats but his contract ran out and he/they didn't renew it. FWW has had issues that show torsion boxes, too, as well as threads here. If you do a detailed search for them, there should be something.
   "I cut this piece four times and it's still too short."

2. 
   nikkiwood | Jan 28, 2007 09:41am | #6

   Here is the link to Marks' web site and his torsion box:http://www.djmarks.com/stories/djm/Torsion_Box_Assembly_Table_94697.asp********************************************************
   "It is what we learn after we think we know it all, that counts."

   John Wooden 1910-

3. 
   nikkiwood | Jan 28, 2007 10:09am | #7

   Here is the same Marks' torsion box, but this link is from the DIY site, which seems to have more illustrations:http://tinyurl.com/2ed2f2********************************************************
   "It is what we learn after we think we know it all, that counts."

   John Wooden 1910-

1. 
   user-181778 | Jan 28, 2007 10:26am | #8

   The "torsion box" has been around in various forms for many years - in the theatre and entertainment industry we called them "stress skins" and used them as platforms  for staging.  Remarkably strong - I've cantilevered a 3/4" ply skin with 2"x2" interior pieces out 4' with no appreciable sagging - while being tap-danced on!

2. 
   colebearanimals | Jan 30, 2007 12:54am | #9

   nikkiwood and all,

   Thanks again for all your advice and suggestions. This is exactly the information I was looking for

                  Paul

2. 
   DonStephan | Jan 27, 2007 10:45pm | #2

   Build a 4' x 4' table first to see if the result is stiff enough for you. Torsion boxes can be built with thin strips of wood for the core, or with paper honeycomb available from http://www.vacupress.com. If the latter, the table can be made even stiffer by having two layers of say 3/4" paper honeycomb separated by 1/4" sheet good.

   When I recently built a 42" x 92" assembly table, the real question was how to get the top completely flat to use for glueups. I finally decided on two layers of 3/4" MDF which I covered with countertop laminate on both sides and the edges. I was going to run through a drum sander at a large woodworking shop but decided not to bother. I could shim under the 2x6 apron if I needed to, but it turned out flat enough to use. I noticed however that the table will twist to follow the floor's height, which dips in one spot.

   I also recently build support table for the table saw like you describe. I wanted to add 12" to the left side of the saw, and did that with a separate piece 12" x 30". That was a mistake because it is very hard to keep level with the sawtable and rest of the outfeed top. Next time I'd build one continuous surface.