I'm thankful I was gifted a retired and incomplete Geeetech A10 3D Printer, and I regard the missing pieces as features not bugs. Their absence meant I'm more likely to think of interesting ideas beyond the world of 3D printing. This was certainly the case when I looked at the Y-axis carriage where a heated print bed used to be.

The machine will still need a work surface of some sort, and whatever it is will still needs to be mounted and I felt there was an opportunity here. Some of my first thoughts were to make it motorized so I could dynamically control its angle. And while a fancy auto bed leveling (or deliberately non-level) mechanism might be an interesting challenge, it was not bold enough of a step away from the shadow of its previous life as a 3D printer.

Thought then moved away from mechanical actuation output and towards some sort of sensing input. I have many ideas for a 3-axis motion control chassis, and the visual measurement device was just the first idea I tried. What kind of smarts are worth exploring for a flat horizontal surface?

Being a technology geek, my thoughts went immediately towards touchscreen monitors and how I might turn the whole surface into a touch pad that can report events and their X,Y coordinates. While this would indeed be exciting, a little research indicates this wouldn't be a very easy and I should scale down my ambitions for a first draft.

The answer came to me during my morning routine, stepping on to the bathroom scale: I can incorporate a strain gauge load cell like those inside electronic body scales. (Or postage scales, or kitchen scales...) This collapses the grand concept of a large touch pad reporting X,Y coordinates down to a single reading distributed across the entire area, but it should be an interesting starting point to have a work surface that can report weight or pressure upon it.