I posted in <___base_url___>/index.php?/topic/13525-the-hexboard/page__view__findpost__p__128066&do=embed about what I was working on:
So rather than clutter that thread, I’ll start a new one.
This is my stupid hacky experimental jammer keyboard using Cherry MX keyswitches.
Inspiration is from here: http://musicscienceguy.vox.com/
You can read up about jammer keyboards, the Thummer, Wicki-Hayden layout, etc. This is intended to be a jammer with Wicki-Hayden layout, but you could make it do any other layout, like Janko.
Do you have any more detailed pictures of your own modified Cherry MX switches or maybe some information about how you did it? I know the principle behind how it works but I’d love to see how you solved the problem. I might opt for velocity sensitivity and seeing as I’m going to have 192 keys to deal with… Well…
This is my first attempt. The more refined version uses a larger, U-shaped contact glued to the actuator, but is essentially the same.
The contacts on the side of the switch are two pins from a female header. These are easily pulled out from the bottom and look like a two-pronged fork. I glue these to the side using superglue, then cut one prong off each and bend the other one down. They are placed lower than shown in the above photo, so after the bend, there’s clearance between the tip and the cylindrical part of the keycap which goes onto the keyswitch actuator.
The contact on the keyswitch actuator is made from the metal disc inside a typical 12mm tactile switch… it’s slightly concave so when in the tactile switch, it’s the part that acts as the switch spring and which makes the contact (shorts the switch pins). It’s just the right thickness, thin enough not to interfere with the keycap, stiff enough to cut into a shape and not wear away. I cut the disc in half, then with the half-disc, first cut a notch to match the actuator, and then trim the other three sides. I gradually trim it to the exact size of the actuator - it’s too small to do any kind of measuring and marking, so I do it by eye and then test fit it until it’s right, or until I’ve cut too much away and have to start again. I then superglue it on the actuator, making sure you don’t get any on the top, or up the actuator shaft. This is why I use a U shape now, instead of the thin strip in the first photo - the U shape means more surface area for the glue, and also makes it easier to align it when you’re gluing it, i.e. the “perfect fit” means it won’t slide out of position during gluing. What’s important is getting it as big as possible, so the contacts have a place to touch it, yet it’s not hanging over the edge of the actuator and rubbing against the hole (and getting pushed off during a depress).
In case it isn’t obvious, you do all that with the switch disassembled, wait until glue has fully dried, then put it all back together, make sure the keycap won’t rub the two top contacts, do lots of tweaking until you get good contacts (test using a multimeter). The spring of the Cherry MX will push the actuator (and the metal contact) against the other two contacts, and since there’s some slack in the actuator shaft, it will “touch” against both the top contacts sort of evenly. I’m not really explaining it right… basically it works, if you tweak the top contacts so they are the same height and a little bit lower than where the actuator wants to be when not pressed.
It’s not a very easy process, still at the experimental stage. There might be a better, easier way to do the same thing. This just happens to be the way I did it first, because it’s what I had on hand, hundreds of tactile switches lying around, and a few female headers. It’s not that cheap either, salvaging a bit of metal out of a 30 cent switch… but then maybe that’s not too bad… Worst case guestimate, I’ve used 100 tactile switches for 96 keyswitches, so that’s only $33. I’ll pay that to add velocity to a keyboard.
Anyone wanting to do the same thing needs to experiment and learn their own method of doing it, how much glue to use, where to position the bits, esp. how to cut the discs, since cutting is done by hand. I mean, I could write up how I do it, but then if you follow that process, it might not work for you. It works for me because I’m crazy and have good eyesight and can cut 0.1mm slivers off a tiny piece of thin metal that I hold down with a finger. You might be half blind with fat fingers and my process would be useless. DIY! It’s not rocket science.
In all likelihood, it would have been quicker and only marginally more expensive to buy an Axis-49, connect it to a Core32 and run my own firmware to get Wicki-Hayden layout, instead of requiring some PC software to remap the notes. That thing seems to have good travel, hex keys, velocity sensitivity, rubbery goodness. Why did I bother then?
What I’m doing is a hacked together experiment… I mean, it will work, it will have velocity sensitivity, it will even have blinken blinken.. the experiment is more to do with the ergonomics… does an isomorphic (jammer) keyboard need hex keys or round keys? can you use computer keyboard keys? does having the actuation point half-way down the travel (instead of at the bottom) make a difference to playability? does familiarity with PC keyboards translate into a shorter learning curve? does using a computer keyboard keyswitch, preferred by typists that prefer not to “bottom out” when typing, result in some advantages when used in a music keyboard?
I’ll be happy when it’s put together and works, I’m just not saying now that it’s going to be anything special, or some great leap in keyboard design. It’s just an experiment. At the very least, it will be something interesting to jam with and help me learn music without being held back by the classic piano keyboard layout.
