"Dave, I can't do that" wrote in message
...
Guys,

I hate to mention the topic of wood, but I want to mount a
3D-printer on a flat stable base so I can move it around without
disturbing the delicate (poor design) setup.

I cannot afford a 24" square piece of 1/2" aluminum and cannot lift
a 24" square piece of 1/2" mild steel.

So, I am looking at 3/4" MDF, OSB and plywood, but open to other
helpful suggestions, but low cost is the operative.

Which of those options is likely to be the most stable? The machine
has many brackets for attaching to a base, so flexing and stability
is at the pointy end.

Thanks

You might look for a used tooling plate.
http://www.ebay.com/bhp/tooling-plate
-jsw