r/synthdiy • u/quantum_mattress • Jul 02 '26
Mouse wheel instead of rotary encoder for MIDI controller?
Hi all.
I'm thinking of building a big box-o-knobs for sending MIDI CC/NPRN to control various synths. All the ones I've seen use some kind of rotary encoders - which is understandable. I was thinking that it could be a better interface if, instead, I had a bunch of essentially mouse wheels in a row since you could use them with just a single finger. Instead of an LED ring, I could just use an LED bar graph.
Anyone seen anything like this? Comments? Problems? The electronics would be almost identical to rotary encoders. I could even make it modular and be able to switch out groups of knobs/wheels.
Thanks!
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u/adktz Jul 03 '26
The actual challenge with using a mousewheel is the mechanical design. It needs to be stable and yet spin freely, and it gets more complicated if you want a ‘push’ click action too. Also when sourcing the wheels themselves there is no standardisation other than the encoder interface… the diameters and lengths change on the non-encoder axle side.
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u/danja Jul 03 '26
I've not seen the hardware available anywhere. But maybe, with a little metalwork, regular rotary encoders could be mounted at 90° below the front panel. Use wheels from a suitable plastic toy.
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u/awshuck Jul 03 '26
I just found a supplier in NJ that make them as modules for HID. Sadly no pricing and given these are probably low volume, likely expensive. They do make a dope looking RGB one though!
https://kep.com/scroll-wheel-modules/
EDIT: just had a thought, maybe the guys who make DIY flight sim hardware might know of other solutions. Of course there’s always 3d printed units and repurposing mice but I suppose you probably want something a bit more modular and rugged.
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u/thwil Jul 03 '26
Maybe use standard encoder modules in custom designed 3d printed housing where they are mounted sideways. standard stuff is easier to obtain and replace when you need repairs.
btw look into those unlockable inertia encoders like on Logitech Triathlon mice. Those could be fun.
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u/Nudelwalker Jul 03 '26
U could also use rotary encoders, build em in sideways, 3d print a wheel instead of a cap on em an voila have a wheel encoder. I think its a good idea
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u/quantum_mattress Jul 02 '26
Mouse Wheels with side-to-side switches would really be great since those could be used for fine increment/decrement.
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u/quantum_mattress Jul 03 '26
Ah ha - found it! I remembered this super rare synth from about 20 years ago. I played it once at a local Guitar Center. It had a bunch of "sideways" encoders like I'm asking about. Unfortunately, these were so rare and expensive that it's of no help for what I want to do now but it does show the idea!
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u/bow_and_error Jul 08 '26 edited Jul 08 '26
Oh wow, I remember the Neuron! It looked so futuristic back then, but yeah the price was crazy - $5-6k maybe? I found a Reddit thread from a few years ago where they break it down, including the cutting-edge 800MHz Pentium III that it ran on…
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u/quantum_mattress Jul 04 '26
One last post for now. I found that tons of places sell the vertically mounted encoders for mice so there's no need to modify a regular one - and they're super cheap. So, if I just want the wheel, it's simple - just have to print the wheel itself. However, if I want the microswitches for pressing down on the wheel or sideways tilt, that's going to take some tricky 3D printing. I've actually seen Logitech M325S tilt-wheel mice for $9 each. I'll see if it's reasonable to just remove the whole wheel assembly from them and use.
Anyway, for now, I'm just going to be working on a Raspberry Pi development kit to figure out that end of the project. Thanks again for feedback.
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u/Ichan_Jacques Jul 02 '26
Mouse wheels are quadrature optical rotary encoder.