Newbie- MDF stability question

[kvcummins]

I'm in the planning stage of my first CNC, and I am trying to figure out if I can put some cutouts in the MDF structure to reduce weight without overly compromising the stability. I'm planning on a fairly smallish machine (maybe a 2'x4' bed) with 3/4" MDF. While I'm not expecting micron accuracy, I'd like to actually be able to use it for some decorative work, and reasonably precise cuts (for a 2nd machine?!).

My thought was to cut out triangluar sections, leaving an 'X' shaped framework in the MDF. Will this still be stable enough? How large should I leave the cross-members? I tried some Googling, but I didn't get any useful help.

I'm a techie, and computers are my baliwick, but structural engineering is a black art...

[ger21]

Weight is actually your friend. The only problem is that the more weight you have, the more power required to move it.

MDF is very flexible when cut in smaller strips, so I'd guess that in most cases the cutting you're talking about would make for a weaker structure, but that would also depend on the design somewhat.

[ger21]

Substituting 1/2" MDF if possible can save you quite a bit of weight as well.

[kvcummins]

I'm following the basic design found at http://www.buildyourcnc.com, and was thinking I could reduce the weight, allowing me to use smaller motors (this is a really threadbare system; I'm avoiding the thought of controllers for now).

Cutting sped isn't as important for me, which (I think) will reduce the issue of chatter to a certain extent (or am I being overly optimistic?)