Plastic Hold down

[vetteboy86]

My company is thinking about buying a CNC machine, and I am the guy to lead the charge. A couple things I am trying to figure out is how to hold the material down, and also what if anything goes between the material and the table itself?

So as I am reading I learned that there are vacuum hold down tables, however I can also get T slot table to allow me to hard mount this material. What is better, and are there still other alternatives?

Also, how do you cut the material without cutting the table? I know the Z height is controlled but to route completely through, the tooling will for sure contact the table? I was doing some reading in finding something inexpensive to place between the material, and the table, but then that presents issues with vacuum.

Thanks in advance for the replies,
Craig

[Geof]

Do a search using the term 'spoil board vacuum table'

Something such as low density MDF is put on the vacuum table and the plastic to be held down goes on top. MDF is porous enough that the vacuum can 'suck' through it but a bit of holding power is lost.

Also look for posts and thread by CNCRob and greolt they have both provided a lot of info about vaccum hold down systems.

[vetteboy86]

Thanks for the search ideas. I did run across the use of the mdf board but didn't realize that you could pull vacuum through it. I figured one would have to route vacuum passages through it to hold the material.

Thanks for the info!

[Micro Rotors]

Are you going to machine plastic? If so what thickness?

We use Double sided stick tape for Plastic and Ren Shape but it depends on the thickness. Also we use industrial hot melt glues.

As far as the table, a piece of aluminum will do.

Bill