In the never-ending search for perfect printing, I've taken @dc42's Delta Calibration wizard code from his Escher3D site, and translated it into Java. I did this because I couldn't understand why it was giving strange answers , and I thought I could perhaps debug it. (Turns out I'd misunderstood what the outputs meant). Then I had a brainwave! and linked in a serial port library, so the program can talk directly to the printer. It sends the printer to each probe point at the press of an on-screen button. What was a tedious chore has become a quick and simple process: repeat several times [press "Goto" button, enter the dial indicator reading], press "Calculate", press "Send Gcode" (I've also added a button to send the calculated M665 & M666 Gcode strings to the printer). Probably it would be a good idea to have another button to save these settings to EEPROM. And a final step I still have to do (since I use Repetier) is to automatically update the Configuration.h file with the calculated values for the tower angles, diagonal rod length, and delta radius. And maybe even invoke the Arduino IDE to compile the source code and reflash the printer automatically?
Anyway, the upshot is that I now have what I think is a really useful tool, which I'd like to share with other people. My plan is that it would be Open Source, which Dave is happy with.
However, I'm of a curmudgeonly age, and a bit lacking in Java UI and Git skills (I'm aware of Git as a project-sharing mechanism, but my actual use of it has been limited to downloading zips of other peoples' work, and an occasional 'git clone' for the same purpose), so I'd like someone to set up a Git repository somewhere, and maybe teach me a bit about how to make that work.
And someone to redo the UI. The program does work, but it's a bit ugly, and gets uglier on different sized screens. I'd be happy with different people doing the Git and UI bits. If you're keen but don't like Java or JavaFX, I think it would be easy to translate into some other language. However, I'd like ot to remain cross-platform.
It would probably be good to have some people with non-Repetier firmware to test that it all works OK.