I have no information yet on Mr Engels. Doing researh on the web on how the fingerboard might work I found a product made by Doepfer . It is call the R2M -> Ribbon to Midi controller. They used an industrial “Position Sensor” for the controller. Check the web site for more details http://www.doepfer.de , it is very interesting. You can download the user guide for the product for more insight information.
Oh yes and I almost forgot some of the most essential info— several synths in actual production have good ribbon controllers, check out Kurzweil sp 88, Roland Ax-7, korg triton extreme. I also saw and played with an old (70’s) big electronic church organ with a really long unknown ribbon controller. Electone model E-5AR.
Try to find a synth-organ repair man to help explain how these controllers work (that’s my next step here in SP , I already found the offical jap repair places, just need the time to go see these electronic wizard repairmen—
I just put all my web-site research addresses into one archivo, but its late and i haven’t been able to put them into the forum context- drrrr– So if u wish, send me your real authentic e-mail address and i will send this wealth of info to u John Spindler firstname.lastname@example.org
I´ve seen the Doepfer products, they are interesting. When I get the time Ill send you all the internet
> addresses Ive found (there are many) dealing with ribbon controllers, linear potentiometers, conductive plastics etc. I have had some success in my kitchen myself, creating quite a few linear potentiometers using various strange mixtures of epoxy, paint, graphite powder, carbon powder etc.