[SpookyDad]

I was considering putting a 3/4" MDF sheet on top of the torsion box of my table as a spoil board. Then it occurred to me if I machined t-slots into the MDF I could also use it as a way of holding work down as well. Woodcraft sells a T-slot cutter that will do this.
http://www.woodcraft.com/family.aspx?familyid=1774

If the spoil board is anchored to the table first, then the slots will be parallel to the x axis automatically.

Has anyone tried to do this?
Any potential flaws in this plan?

[Geof]

....Any potential flaws in this plan?

Maybe someone else will chime in with a comment. I think a potentially fatal flaw is that MDF is not strong in tension; particularly tension in the direction you will apply it with a tee nut inside the slot being pulled up.

[lakeside]

I'm going with Geof board will give

[ger21]

MDF splits very easily, and it's weakest at the core. Cutting T-slots into it will give it a place to split at it's weakest point.

[2muchstuff]

If you are set on using wood then I would suggest using a piece of 3/4" veneer plywood. They are much stronger due to the numerous number of plys. I'm not refering to the stuff the Depot or Lowes sells but the stuff that can be gotten at a hardwood lumber store.

Another alternative would be to install aluminum T-slot rails sunk slightly into the MDF.

[gun_maker]

You could always do this. I will probably be building something like this for my machine once I build it. I have seen this done larger machines like router tables and table saws. You basically surround a Steel channel. I dont remember the exact name but they usually hang lights and air ducks off of these in industrial buildings. I know you can get it in large or small sizes (1/2" all the way up to 3") I hope the picture help I drew it up really quick in Sketchup

[2muchstuff]

I dont remember the exact name but they usually hang lights and air ducks off of these in industrial buildings. I know you can get it in large or small sizes (1/2" all the way up to 3")

The channel you are refering to is called Unistrut.