Torsion box thickness for a mobile base?

[Craig Stueve]

I am planing to build a torsion box to use as a base for my Jet contractors saw. The base will be approximately 2' X 4' and have 4” locking casters at the corners. I will be placing a cabinet with some provision for dust collection and drawers for storage between the base and the saw.


My question is if I am using 3/4” MDF or ply for the torsion box and cabinet construction how thick do I need to make the inner torsion box members? Is 3” necessary or would 2” or even 1.5” be enough for what I am planing? I assume that at some point the inner members become too thin to be of any significant structural value.


Thanks for any input,
Craig

[Ron Franssen]

Check out this link to DIY and David Marks. He built a 4 x 5 torsion box and the steps are relatively identified in the web pages.


http://www.diynetwork.com/diy/ww_materials_products/article/0,2049,DIY_14442_2278181,00.html

[Brett Baldwin]

I don't know if you are interested in a similar plan but this came to mind when you described your idea. http://store.woodstore.net/mosaroce.html
I was considering this when planning a mobile base for my saw but ended up making a metal one instead.

[Rob Blaustein]

I just built and installed (thread to follow some time later) a 27" x 20" torsion box extension table for my table saw out of 1 x3 poplar (so around 3/4" by 2 1/2 inch). The design was motivated by David Marks's table as referenced above. Mine has a 3/4" melamine top and it is VERY sturdy (and fairly heavy). I'm guessing the poplar is a lot lighter than the MDF and will be just as strong, though I have no data to back that up. Marks used 1/2" MDF for his rows and columns and framed it with 3/4."

[Bart Leetch]

Craig

You really don't need a torsion box base for your contractors saw base, it will rob room for storage from the cabinet your planning. The one in the link below I made for my C-saw it is a little over 5' long & is made of 3/4" plywood & has 1 2x4 spaced just in from the front & back with the ends rabbited back just enough to mount lockable castors. I could have done without the 2x4's. Check out the Grizzly castors they support I think 150 lbs each & lock the wheels turning as well as the castoring.


http://www.sawmillcreek.org/showthread.php?t=14597


The long cabinet in the above post has a torsion box base but then it spans over 7' & has a lot of weight in it.

[Howard Acheson]

I'm with Bart. A torsion box for a mobile base doesn't make sense to me. All the weight is on the legs so if you put rollers under or attached to the legs, you are set. Torsion box construction only is required when the weigh is over some other area not supported from directly underneath.

Do you have a picture or sketch of what you are planning?