Delta bed levelling

How exactly does delta bed levelling work?
I'm building a GUS Simpson, a grounded delta. Nicholas Seward is selling printbeds, but they're quite expensive, so I was thinking I might just use a sheet of glass. I was a bit worried, though, that the way the printbed mounts could be important to the levelling process, and I'd lose that if I were to use my own bed.
If I were to mount the bed in a way that couldn't be adjusted, would that be a problem? Is bed levelling a digital or physical process?

It's both a physical and digital process. You'll need to manually adjust your endstops and digitally adjust the printer radius, carriage offset, arm length, and tower rotation. It's a process, but once you understand how it all works, it's pretty straightforward

Does it ever involve moving the printbed, like it does on Cartesian bots?

Edit: Printbed, not printed.

Edited 1 time(s). Last edit at 01/21/2014 01:40PM by epicepee.

Did you mean "printbed"?

If so, no. The bed is stationary.

For the record, GUS's bed is currently only leveled digitally. There is no manual adjustment.