[Marko63]

Does anyone have any experience stacking multiple pcs of 3mm MDF on a vacuum table for routing on a KOM router? WE have not had sucess doing this and normally have to clamp anything with multiple sheets.

 

[Stick486]

I would think the vacuum table will hold only the 1st sheet/piece..

 

[DesertRatTom]

1. Drill large holes in all the same size pieces but one, and put that on top. Probably needs to be fairly large holes, and plenty of them.

2. Or stack glued up pieces in twos, threes and fours--or however many you typically stack.

3. Or stack them and drill 3/8ths holes in all 4 corners, then cut 3/8ths dowels to lengths just shy of the heights that will fit and be just slightly below the top layer's surface. You'll have a lot of dowels, but dowels are cheap. Slight sanding may be needed to have them fit. Clamp BEFORE you drill the holes.

I am assuming you want the top layer to be smooth and flat for free movement of the router. Suction will hold the stack in place, but you could drill positioning holes through the bottom layer and the top of the sanding box, put a positioning pin in the bottom layer, and the whole thing will be in register.

 

[MEBCWD]

Mark, I think it will take a little time for the vacuum to work it's the way through the stack of MDF sheets. They would need to sit on the bed with something holding them flat, maybe weights, before the vacuum could work the way through the stack. Just like a new vacuum bed it takes time for it to work to its fullest ability. Remember the vacuum will follow the path of least resistance so if the sheets are not flat against the bed and each other you could be loosing too much vacuum.

You also say multiple sheets so that might be too many sheets to expect to work feasibly at one time.

 

[Cherryville Chuck]

MDF has a fairly slippery surface like melamine coated particle board does. The only way the CNC router could hold it at a place I worked once was with the rubber seals it sat on. They were sticky enough to keep it from sliding. I ran a CNC beam saw that could cut 7 sheets at once but it had a clamp bar that came down just before the saw made contact.