Nice work on the LED head, very well put together and the finished product looks superb with printing results to match by the sounds of it.
I am new to APUG, but have been looking at this very thread for months now with interest - I just recently completed an LED head for my LPL7700, in an attempt to create a brighter light source with a VCCE head, but it was a complete flop. I wanted to utilize the existing mixing box and filter set in the enlarger head, which is designed for a halogen.The LED I used was top notch, a Philips HBM module, with the matching 1-10V controlled dimmer constant current driver, 6000 lumens, and 3000K colour. However what I did not count on was how concentrated the light source from a 100W dichroic halogen lamp is, and instead was focused on the lumen output of the module, without thinking about it fully. The LED module is partially diffused from the start, or at least is not focused by a parabolic reflector like the halogen, I see now why it did not work. The light output was poor, and most was lost before it got to the mixing box, not being directed and all.
Anyway, your design has re-inspired me to try a new project, as I have recently picked up a Devere 504 enlarger with a Dichroic colour head, and want to try and tackle a project based on the ilford multigrade head, and using a green and blue LED array in a configuration like yours and trying to emulate the Heiland LED VC source. I was going to use dimmers to control the intensity of the green and blue LEDS individually and try to come up with some 'grades' based on the step wedge I guess.
I just noticed you had a link to Stormpetrels VC head, do you know how that went in the end?
Thanks for sharing your work!