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by dirkderkdurk 732 days ago
Hah! I'm working on something very similar!

The screens are by far the most tricky part to get right, size and positioning. At first I thought about using one of the super thin Sony mobile screens for the entire thing, then using an overlay to separate them, annnd then to make it tactile with knobs, the knobs would touch the screen, and the phone would send the co-ords to the playback device (RPi in my case).

But that's because I wanted a very "thin" end product. Making it deeper allows for some more creative layout.

I've settled on a linear potentiometer driven by a stepper motor, and it's working out for me so far!

Good luck with yours! Got any links to follow it on?

Here's mine FWIW: https://youtu.be/GjmFbgqFeMQ

2 comments

Yes, thin would be super hard to do - I expect at least a good few CM in depth. The Alps fader alone is almost the biggest factor. This is a link to a German electronics store that offers the same I have been using: https://www.reichelt.com/de/en/alps-rsa0n-studio-fader-motor... I will see if i can find the box with my prototype setup because its way smoother than your setup is. its unbelievable smooth when using a cheap analog servo board.

From your video you came to almost exact the same solution I have. :) I really can suggest trying to run it from a servo board - it has all the stuff for smooth movement already in it.

I'm using a Pi Pico now with a stepper motor (no video of it yet), and it's super smooth, indeed!

I was thinking about using a "SoftPot Membrane Potentiometer" to bring the chonkiness down a little, where the knob on the front would have a little nub at the back which would press against the strip and give you the same kind of effect (but then you need a way to drive that nub, of course).

I also thought about using the stepper motor and spiral combo out of a CD-ROM drive, maybe putting an encoder on it, but the spiral isn't long enough, so meh.

I'm still waiting for screens from AliExpress before I make an updated video, otherwise it'd just be, "look, it's smoother now, yay".

I want to make this as well! Maybe we should all collaborate.
I'm currently doing tiny bits of way too many projects, so I'm as reliable as Trumpet Winsock sadly. But we could encourage each other to stop procrastinating!