To begin the tweaks I looked for a method to level my bed that was considerably more accurate than using a piece of paper and just feeling for the right gap. So we now have a simple (currently manual) bed leveling method that's much better than relying on paper to set an unknown gap from nozzle to bed...

After implementing this method my prints are actually better, it's Murphy's law in reverse (O'Toole Inverse Law), other things started to work better... it's true, absolutely true... ;)

To begin with I noticed that the hot-end and aluminium (aluminum) bed were electrically isolated from everything, that meant I could connect wires to them to form a normally open switch. If I then home the hot-end (to set its height and first location for the leveling procedure) and then screw the associated spring so that the bed raises and touches the nozzle, I could manually get perfect alignment of the bed.

As I actually required a gap of 0.1mm between the nozzle and aluminium bed, or more precisely the glass, I added some copper tape to the top of the glass bed and voilà the switch would activate exactly at the correct height...

The manual process:

Currently I use my multimeter connected between the hot-end and each of the copper tape sections and adjust the appropriate spring on the bed till I hear a bleep. The whole process takes about a minute and the first layers are now perfect every time...

The automated process:

This process could then be automated once I had update the firmware adding a boot-loader and the auto bed leveling code... (by default the printers firmware doesn't include a boot-loader)...

The only real issue is connecting the four pieces of copper tape together and adding a wire from them back to the controller along with a wire for the hot-end to form the new bed leveling sensor...