Thanks for getting back to me and once again: awesome project!
aleath the key tops are made in two layers, 6mm mdf and 3mm white acrylic, which are then glued together. Laser cutting 9mm white acrylic would also work, but thicker material has a more prominent slope from the laser beam taking more material from near the top, and cost increases non-linearly with material thickness, so that it is often cheaper to laser cut two thinner layers and glue them together.
Yes that was my point. You find that 6mm is still cost-effective even when done for 50+ pieces (and spares) for a whole piano?
aleath I outsourced the laser cutting for this prototype, and it wasn't too expensive.
May I ask where an how much (ballpark, not exact figures okay)?
aleath The displacement of black/white keys towards each other due to rotation around the pivot point proved minimal enough that it could be compensated for with a minimally increased gap between black and white keys.
This is very good to know. From the video it seems okay. But I played one piano once with an increased gap between keys and it wasn't fun. So I hope this is really minimal and I plan exploring this myself too. Or alternatively (see idea below) making the lower plies smaller to achieve slope.
aleath I was hoping to eliminate as much manual labour as possible with this design, but it still takes a while to assemble… that's the unfortunate trouble with 88 keys!
That is part of the reason I said it was too complicated and/or expensive. Now that you have made vast majority of the setup in laser-cut parts, I am thinking of a way to reduce labor. It will work best if you could also manually create the laminated part of the keysticks by gluing them together. This sounds like more work, but keep reading and tell me what you think.
Have you considered using matching slots to align all the parts with each other? You could put tiny screws or tiny "blades" to keep all the parts in place, somewhat similar to how a key in a clavichord is kept from going letf-and-right with those slots and blades in the back of the rack (see pictures at http://www.bostonclavichord.org/what-is-a-clavichord/) -- having to glue each keystick would be more labor, but having the slots in place on all parts will make it immediate positioning with two blades per key and a single clamping of the various plies (potentially of different sizes to achieve slope and not having to have enlarged space between keys). All of that will work fine for the bottom parts, but can one make a slot in the white acrylic which is not through, but blind. Is that possible?
And most importantly: what would be the cost of this approach? Are there too many parts to cut to make it cost effective?
aleath I'm familiar with the Cybrid project! I followed it with great interest, and seeing the success of that was one of the things that encouraged me to embark on my own project
@CyberGene has really been the pathfinder for all of us. As you probably have seen from my other message I'm doing @JayKominek 's piano-conversion at the moment (and frustrated by the parts shortage)
aleath The repository is a bit messy, but the code is on github:
This is very cool. And very similar to my own experimentations, which you can check out, if you haven't already. The Pico-related experimentations are below (but do check the rest of the repo too if you have time. https://github.com/davidedelvento/Mybrid/tree/main/RaspberryPiPico
aleath I will probably make the drawings (for laser cutting etc) available somewhere (maybe as a release on github), once I have fixed them up. They are currently a jumble of many slightly different versions of parts.
I'm really looking forward to that. If I can, let me nudge you to share one or two "best" parts you have so people like me (who never used a laser cutter, but I used a 3D printer exactly once) can take a look and start experimenting. Even with the understanding that they are only temporary and not the final design, just to see what it entails.
aleath That haptic piano looks incredible, I would be fascinated to watch your progress if you tried something like that.
If I try something like your project, it will most likely be haptic. The most difficult part so far (besides building the keyboard which you are "solving" for me) is finding a suitable solenoid. Most inexpensive/small ones are too wimpy to produce enough force, and most good/strong one are too big and definitely too expensive (about $50 each, or more!!) to be viable for an 88 key instrument. I think something appropriate ought to exist, just that I haven't found it. Then, most electronics drivers are made to move the actuator in a specific point regardless of force which is typical and natural for any robotics or automation project. For this project, rather, one needs a specific force regardless of position which requires a different driving approach, not the one which you can find in off-the-shelf projects. The good news is that this other driving approach is actually quite simpler to design and implement, nevertheless it's an analog project which requires to be done from scratch.
aleath I would be interested to know the brand of enamel you used.
From your spelling I assume you are not in the USA, so I doubt you will be able to find it, but here it is anyway:
Brand: RustOleum Professional (related, but not the same as the regular RustOleum easily found in all hardware stores)
Model: High Performance Enamel.
As always, carefully manage the application environment (temperature, humidity, absence of wind and dust) is paramount to successful results.
Looking forward to chatting with you about these projects!!!
