[BobWarfield]

Part of the reason why its better to work from the front left corner is because it keeps all of your X and Y values positive. Another is that materials are not always cut to the same relative size. That means you have to either find the smallest sized part and use that for your setup or adjust the datum further into the part to compensate for the occasional undersized block. That's something you learn from experience, not by taking a course or two in programming and calling yourself a machinist. :cheers:

If you've got the lower left corner of the fixed (rear) jaw as the datum, you will have negative Y's and positive X's. There's no worry with that I can see. If it bothers you, I suppose you can use a reverse vise so the fixed jaw is at the bottom instead of the top.

As for different sizes of workpiece, they don't matter either, as long as they're all bigger than the part. If the left and top edges of the workpiece are not squared, you simply leave a little allowance for the part so it isn't aligned on X, Y = 0 and let the profile operation do its thing.

That's the whole point of the approach, is you can bandsaw a close enough workpiece, pop it on the vise and go without changing the program, touching off, or anything. Just push the green button.

The system works well for the shops I've talked to, and I like it myself. Some of them are using fixture plates set up the same way. They'll even start their cad with the fixture plate or vise jaw on the drawing so they can line up the part. It's not perfect for everything, but it gits 'er done a lot of the time.

Cheers,

BW