MIDI Controller - as thin as possible

Description

A small footprint controller with just 3 fader inputs running on 'linear rails' (PLA bushings).
This is part of another project
An online drawing app that let's you change colors via MIDI Controller

Convential low cost faders usally feel a bit stiff, as part of an ease in/out feature I guess.
With the drawing app you change all 3 color inputs constantly and with just one Finger, so you want them to run as smooth as possible.

Details

- Arduino Beetle (AtMega32u4) with 3 analogue pins

- ground down potentiometer tracks to 0.2mm

- 2mm rails, overall height is 5mm

- carbon resistor tracks can't be soldered, had to mechanically fasten them with M1 screws. If someone knows a PCB service that will make 0.2mm PCBs with printed carbon resistors, let me know.

- the tracks are very heat sensitive with weird failure state (partially working)

- make one hole of the wiper carriage square and oversized, as done on commercially faders with linear rails, to make them more tolerant against misalignment of the rails.

- soldering enameled copper wire is a pain, I butchered the prototype until I discovered headphone cables

- made an USB cable from 4 core headphone cable (1.5mm) too, nice for such a light device.

- first layer typo is generated and exported as gcode via Sverchok, a Blender addon for parametric design

- arduino sketch has a multi-map function that allows you to remap the analogue readout in a non-linear way, to recalibrate 'linear' potentiometers or even convert logscale potentiometers to linear.

Files

RGB_single_nozzle.gcode

gcode - 2.86 MB - 02/08/2020 at 10:16

Download

photo5355253662227737537.jpg

one oversized square hole of commercial fader

JPEG Image - 98.49 kB - 11/12/2019 at 08:02

Preview

thin_midi_controller_CAD.stl

Standard Tesselated Geometry - 318.25 kB - 11/11/2019 at 16:51

Download

midi_controller_as_thin_as_possible_ARDUINO_BEETLE3_inputs_2019.ino

ino - 4.18 kB - 11/11/2019 at 16:51

Download

Discussions

MasterOfNull wrote 10/25/2020 at 18:30

The case you've made here almost qualifies as art for perfect under-extrusion at the surface. I like this a lot for several reasons.

Are you sure? yes | no

heinz wrote 10/26/2020 at 13:09

Thank you Daren, means alot coming from you.

Im afraid there is no under extrusiuon mastery going on.
Surface finish is the result of printing with 3 colors at the same time..or did you mean something else?

Are you sure? yes | no

MasterOfNull wrote 10/26/2020 at 18:40

Oh well that explains it. So what I'm seeing is the Colgate effect from a non-active mixing hot end feeding multiple filaments.

It's a good look though for this. I like it.

I did something similar on the Rose project where I used the infill pattern and order as part of the design for the petals.

Are you sure? yes | no

heinz wrote 10/27/2020 at 07:55

Now that you mention it, it looks like sparse infill filled from the back.

I reversed parts of the infill to go in a uniform direction to keep the finish consistent. (partly failed)
Toothpaste effect always looks quite interesting on the bottom layer, no matter the infill pattern.

Are you sure? yes | no

davedarko wrote 11/11/2019 at 20:27

pretty neat! I was thinking about flat faders the other day, when I saw one of those handheld winamp renders

Are you sure? yes | no

MIDI Controller - as thin as possible

Description

Details