how much can plywood move?

[knight_toolworks]

I got a job I bid on to cut these part out of 3/4" marine mahogany plywood. they are rectangles that have a bunch of 3" holes in them that are chamfered.
the thing is they have a tolerance of +.01 I will have to make a gage to check the holes but the thing is could the holes change size with the wood movement when they are shipped more then that? I know ply can change thickness not sure about length and width.

[dlcw]

Steve,

I've never had a plywood part change in size other then VERY minor change in thickness. The thickness change happens mainly in Goldply (the hybrid of veneer plys and MDF). The veneer plywood is extremely stable.

I've built many things with plywood that would have started opening up miter jointed solid-wood edge banding if the plywood changed in length or width.

[hh_woodworking]

Plywood should not change in length or width do to it's construction. Each layer is at a 90 degree angle to each other for stability and strength. the more layers the stabler the plywood is

[ken_rychlik]

The safest thing to do is have him supply a piece of wood and run him a sample or two.

Then you know for sure that he is happy with it before running a bunch of them.

[knight_toolworks]

this is a strange job. they are in another state about 3 hour drive. but they have the ply t a waterjet place. but that place did not want to do the bevels on the pieces so they found me and I bid on it. of course I will do them with a hand router. Then somehow they will pick up the part or have them shipped.
I have a friend going to pick the wood up and paying him to do it. It would be nice doing a sample but the part is too big for simple shipping.