Need a little help

[wdp67]

Morning All
I have a project I am working on and need a little help. I am just a hobbyist, that usually makes parts one at a time, but I have a project that involves cutting multiple parts out of a single sheet of HDPE. The sheets are 8" x 24" and there will be 8 peices cut out of that sheet.

What I need help with is how to clamp the sheet to the table, and be able to flip it over to do the pockets on the other side lining up with the first side.

My milling table has a t slot on the front of it, so my idea was to build a fence that is on the front of the table to register the long side of the plastic. At the left end of the table do the same build a fence that is attached to the tee slots in the top, and use anotherthinner peice attached to that fence to clamp that end down. At the other end use some toe clamps.

What I am unsure about is when I flip it over, it is critical that the pockets and outside profile line up, I am not sure how to do this. Any help would be greatly appreciated.

Thanks
Walt

[Gmaan]

What I have done is drill a tooling hole thru the material that is not used for a part, note the position. When you flip the material indicate the hole and set you WCO as required.

[handlewanker]

Hi, when you turn over front to back, (not sideways), all your measurements are mirror image, that is still from the same edge.

But when you do them on the other side of your board you'll have to recalculate the pocket edge positions (or centres if they're round) from the opposite side as the mill doesn't read backwards on the Y axis.

The end measurements remain the same.

A handy tip is to mark them out in pencil when you turn over and check they line up BEFORE you start cutting, .....BTDT,
Ian.