[jdholbrook]

I'm about to use a fixture that is 17" x 23" x 1.25" 6061.
Parts will be 100% plastics.
I'm looking for ideas of how to mount to the mill.

Clamp it in two vises with the jaws on the outside?
Mill pockets on the bottom with a dovetail and mill two sets of vise jaws to match?
Mount to the table?

Ideas?
Suggestions?

[stevenSmidley]

That seems like a large fixture to me. Too big for mounting in any vise I've worked with. If you mount right to the table you only have to worry about 2 surfaces being in perfect contact. In a vise you'd have twice as many surfaces affecting the flatness of your fixture (the vise could be poorly mounted to the table). But if you do mount your fixture on top of your vises some how, you save yourself all the time of removing those vises.

The Kurt vises we use at my work have 2 clamping stations and they can not be used to clamp a single large part using the 2 outer most jaws for the clamping. The outer jaws have some springy action that is required for clamping 2 different sized parts in the same vise. So be careful if that is what you had in mind to do.

[Louis_Cannell]

I have mounted some large lumps of 39x6x4" Aluminium on an X1 micro mill by drilling a few holes in short lengths of 1" steel box section that straddled pieces as hold down succesfully get imaginative and think outside the box, there are no problems only solutions waiting to be found. As above post I would consider each additional level of complexity another chance to introduce error so keep it simple.