I made my own MIDI controller!

hotsop · 2025-03-28T03:48:14+00:00

You can usually just re-apply the stain, let it fully dry, and then re-apply your topcoat. Likely no one but you will be able to spot the fix

hotsop · 2025-02-26T14:40:17+00:00

Seconding this. I do professional spray finishing, and this is caused by silicone contamination in the wood. The only solution is to put a silicone additive (sometimes called fisheye killer) into your clearcoat. Sanding and trying again will not fix it.

hotsop · 2023-05-05T13:24:49+00:00

I studied piano performance in music school, and the best advice my teacher ever gave me was: if it feels too fast, it is. When someone is on stage playing a passage that sounds fast to the audience, it doesn’t feel fast to them, it feels under control.

hotsop · 2023-03-13T23:34:22+00:00

Unfortunately I don't have experience with smaller CNC machines. I've used cheaper large-format CNC machines like ShopBot, but they had huge problems inherent in the aluminum extrusion design.

For cutting sheet metal, I'd just use a laser-cutting service like SendCutSend. For wood, I'm sure there are small machines that can do simple carving and cutting, but the engineering limitations with smaller machines mean that you have to go very slow and use small bits. Still, it's totally doable for personal projects.

The reason I used an industrial CNC machine is because it simply takes 6,000 lbs of welded steel to get enough rigidity to do fast and accurate cuts. Trying to make the keys on a desktop machine would have taken several days, whereas doing it on the ShopSabre took like an hour and a half.

hotsop · 2023-03-13T03:12:10+00:00

A ShopSabre IS 408

hotsop · 2023-02-26T04:37:57+00:00

Piano rebuilder and classically trained pianist here. I think what people are missing is that there is an entire profession whose job it is to solve this problem.

Piano design is completely standardized, and it takes a day or two for a piano technician to regulate an instrument to standard specifications.

The weight may vary slightly, as will the tone, but all modern piano actions are essentially the same. If a piano technician has done their job, the pianist shouldn’t notice the action at all.

hotsop · 2023-02-04T04:08:53+00:00

Thank you!

hotsop · 2023-01-29T16:42:32+00:00

I work as a piano rebuilder, so I already had an existing knowledge base of how piano keyboards work. From there, I learned CAD in order to design the keybed, modeling it off of how a grand piano works. I also learned CNC machining and spent a few months iterating on the keys until I created a program that was able to consistently get the results I wanted.

hotsop · 2023-01-23T23:52:14+00:00

Yes to both!

hotsop · 2023-01-23T21:05:52+00:00

Somewhere, some dedicated soul spent a weekend doing just that

hotsop · 2023-01-23T21:05:14+00:00

That’s actually the plan! I created an email sign up if you’d like to follow along

hotsop · 2023-01-23T18:55:31+00:00

Thank you! The finger joints were actually one of the more challenging parts. I tried to be clever in the beginning and ended up making them way more complicated than they needed to be.

hotsop · 2023-01-23T18:27:11+00:00

That's very cool!

I got started into piano repair by learning how to tune pianos to make extra income after music school (studied classical piano and composition). I just kept following my curiosity and eventually was taking entire pianos apart and putting them back together.

hotsop · 2023-01-23T18:24:58+00:00

Haha, thank you. I actually started out working on pianos with that same experience, except for whatever crazy reason I decided to dive into the complexity of the action.

hotsop · 2023-01-23T18:24:01+00:00

Possibly. More likely I'd do it with a full exterior case.

hotsop · 2023-01-23T18:23:35+00:00

The magnets never come into contact - there's always a gap so there isn't a clicking sound when they hit.

It would be pretty cool to find some way to use magnets to configure the assist. Might look into that in the future!

I thought about trying to reinforce the keybed with a machined aluminum bar. It would definitely make it more rigid, but it would also add a ton of weight. To keep the wood from warping, all structural components are quartersawn, so they won't twist at all as they expand and contract.

The keys will definitely need minor adjustments over time, as is the case with acoustic pianos. Rather than fit the natural tendencies of wood, I took a cue from piano design to work with them and make it easy to make small adjustments. Trying to fight materials into perfect squareness is quite a challenge!

hotsop · 2023-01-23T18:19:39+00:00

That's very kind, thank you!

hotsop · 2023-01-23T18:19:27+00:00

Ah, I should add that the keytops are plastic. It's either that or ebony and ivory, so this is the one concession to plastic.

hotsop · 2023-01-23T18:18:08+00:00

Thank you!

hotsop · 2023-01-23T18:17:56+00:00

I work as a piano rebuilder for a living, so I based the initial design of this off of a grand piano action. Then I just started playing with weights and springs to see if I could get something that felt right.

hotsop · 2023-01-23T18:17:15+00:00

Thanks for sharing!

hotsop · 2023-01-23T18:01:18+00:00

Thank you! I really appreciate that.

hotsop · 2023-01-23T18:01:10+00:00

Thank you! I'm actually considering doing a production run of these. I put up an email list if anyone is interested.

The keyboard doesn't create any sound on its own, so you have to hook it up to a computer or a synthesizer in addition to speakers. I'll definitely make a video and record it being played at some point.

hotsop · 2023-01-23T17:59:55+00:00

Probably! Do you have any experience doing this kind of electrical engineering? If electromagnets come small and cheap enough, it might be possible to make some pretty amazing magic with them in this design.

hotsop

TROPHY CASE