Well, after a quick research the thing I was thinking about is very different from my memory, and there are patents on it... I like the way you're going, and I hope some day you will have the time to show us your math, it's amazing to me how quick you areby Nicope - Delta Machines
To get rid of the spring you could also replace the strings of the DLCJ with flexible blades , I have used such kind of self deploying articulations in the past ]by Nicope - Delta Machines
I have followed this thread from the start, and I think that if the firmware can't handle the math it would not be good for future development as adapting the slicer will be harder than the firmware. I guess Having the same articulation on all the arms could make it simplier for multi extruders (and for one too)by Nicope - Delta Machines