Permanent X and Y position on a 840

Is it about producing the same part over and over again? I did so many different things on the CNC that there simply is no "one way of clamping" which fits all needs.

Basically you need jigs which lets you clamp down your work-pieces with a point (for example front left corner) that is exactly at the same position and exactly parallel to X or Y or both.

Once upon a time I build a table to clamp down PCBs, I have a flat vice which centers the work-piece and some more clamping tools. The key is that, if you want to switch from producing one part to another and you have to switch clamping tool, those need to be positioned at the exact same place. So I use stoppers for that or the natural boundaries of the machine.

Second key is, that your software supports this. In WinPC-NC it was easy, you only have to create different profiles. I think that profiles do not exist for EstlCAM. At least referencing has been added and you can then tell EstlCAM to go to position X/Y and set to 0 there. So you can keep track of the origins of different clamping tools by yourself.
Don't know how it works for UCCNC.

Hi. I set my M55,M56, and M57 in UCCNC to specific location on my spoiler board. (Upper left, lower left, and lower right respectively). I then use my laser to burn 90 degree reference lines to place my work piece. This allows me to quickly set up and repeat jobs any time I want.