vaccum system for cnc machin 2

[jay6706]

I work maint for a furnicher manufacturer that uses a vacuum sys to hold a 8x4 foot sheet of plywood on a table for a cnc machine. flow throw score boards are used under the plywood. we have five vac pumps piped into a one manifold that branches off to six cnc's. before the operator runs the program vacuum is around 27 or 28 hg , by time program is finished hg can drop to 18 hg. my question is are the other cnc's (we have to or three running at the same time affecting the vacuum of each other. also some parts cut are small, about 1"x1" or 4"x4" does there size afect the amount of suction on thim.

 

[MintJulep]

If every thing is piped together in a common manifold then they are all connected, so yes what happens on one will affect others.

When you put on a new sheet of plywood all of the holes are blocked, there is very little air that can get into the vacuum system so the vacuum is strong.

As you cut more and more air can enter through the kerfs and the vacuum degrades.

 

[berkshire]

Somewhere on your machines there should be a pressure alarm that shuts down the XY travel if the vacuum degrades to just above the point where the table will not stop the part from moving.
If you are still holding 18" of mercury at the end of the cut I would say that is pretty good. That's still better than I was getting at the start of a cut with a worn wasteboard.
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor