[HN Gopher] I made a macro keypad with 3D-printed switches
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I made a macro keypad with 3D-printed switches
Author : jstanley
Score : 129 points
Date : 2020-07-06 15:03 UTC (7 hours ago)
(HTM) web link (incoherency.co.uk)
(TXT) w3m dump (incoherency.co.uk)
| grooverut wrote:
| You mentioned the contours on top of the keycap being an issue. A
| good fix for that is tilting the keycap forward 45 degrees in
| your slicer. This does require supports but the top finish looks
| so much better. The tilt technique combined with your filament
| should look very good.
| rolleiflex wrote:
| I caught the same issue, from a slightly different angle. Using
| key caps with that much protrusion surface will render them
| unsanitary in a relatively short time due to dead skin
| deposits, which will cure and fill the ridges. It's not great
| from a health point of view. From what I remember when I was
| doing 3D printing, an acetone cloud bath could help to achieve
| a more glossy, thus more sanitary finish.
|
| Incidentally glossy finish on porcelain-ware for plates, bath
| tubes, toilet bowls and sinks are specifically for this reason
| -- gloss is achieved when the surface is flat to a defect rate
| smaller than the wavelength of visible light, which also gives
| bacteria and organic matter very little to hold on to.
| biggerfisch wrote:
| Usually acetone doesn't work so well on the PLA the author is
| printing the keycaps in. There are other sprays or things you
| can apply to PLA for a good effect though - I'm betting any
| of the things used to make PLA food-safe would work here.
| ChrisKnott wrote:
| Neat project - next time make one with only ctrl, alt, and del.
| Okkef wrote:
| Don't get me wrong, I'm heavily into the custom keyboard scene.
| PCB design, lots of tiny soldering, 'crazy' ergonomic layouts
| with only 36 keys and lots of layers and other tricks.
|
| Still. Why would you want to print your own switch mechanism?
| enchiridion wrote:
| I view projects like this along the same lines as maintaining
| classic cars. It a fun and rewarding project, and you learn
| things along the way.
| Pixelbrick wrote:
| There is a yak, and it is furry.
| EForEndeavour wrote:
| For the uninitiated:
| https://en.wiktionary.org/wiki/yak_shaving
|
| 1. Any apparently useless activity which, by allowing you to
| overcome intermediate difficulties, allows you to solve a
| larger problem.
|
| _I was doing a bit of yak shaving this morning, and it looks
| like it might have paid off._
|
| 2. A less useful activity done consciously or subconsciously
| to procrastinate about a larger but more useful task.
|
| _I looked at a reference manual for my car just to answer
| one question, but I spent the whole afternoon with my nose
| buried in it, just yak shaving, and got no work done on the
| car itself._
| gh02t wrote:
| Fun/learning. This is actually quite a sophisticated
| engineering challenge and there is a ton of stuff to be
| learned. I would love to do this if I had the time.
| iDemonix wrote:
| I've been undertaking a similar project, using an ESP32 currently
| for testing, also have an Arduino Micro Pro to test yet, during
| lockdown/furlough. I'm hoping to customise and sell them on Etsy,
| I've sold code + 3D prints before, but I'm just taking time to
| get the PCB right before I get my first ever board printed.
| Aiming for hot-swappable switches and some LED magic.
| manbash wrote:
| > The switch fits in a 14mm square hole (apart from the
| protruding wires), which is the same size as a Cherry MX switch,
| but the total height from the bottom of the switch to the top of
| the keycap is almost twice as large, about 45 mm vs 25 mm [...]
| This directly translates to increased keyboard height, so it
| would be good to cut this down as much as possible. I should be
| able to lose 2 mm from the wire support at the bottom of the
| switch, and another 1 or 2 mm in the height of the leaf spring
| attachment, but there's no way it's going to be as thin as the
| Cherry MX.
|
| It's a nice concept but the design of the switch doesn't intend
| this project to replace your keyboard.
|
| A nice design nevertheless :)
| jstanley wrote:
| It's easy, just cut a hole in your desk to accommodate your
| over-sized keyboard!
| archarios wrote:
| Could use a height adjustable desk and a book as a mouspad.
| That's what I do for my keebs that are too tall lol
| econcon wrote:
| It's a good project.
|
| If you print a lot, here's my project using which you can create
| tons of cheap filament:
|
| https://medium.com/endless-filament/make-your-filament-at-ho...
|
| If anyone can contribute diameter control algorithm, please let
| me know!
| regularfry wrote:
| Is it the control algorithm you're after, or an output diameter
| measurement technique? You don't mention how you're measuring
| the width at the extruder die or after the freeze bath.
| m0xte wrote:
| Those contacts will oxidise almost instantly. From running morse
| keys for years, you need gold or phosphor bronze.
| jstanley wrote:
| Thanks, I will keep an eye on this. Do you reckon gold plating
| would suffice or is it likely to get worn away?
| mdszy wrote:
| Gold plating is used a lot in electronics contacts to prevent
| corrosion, it's a pretty proven method that should work just
| fine without wearing away easily. As far as I understand it,
| the gold chemically bonds to the metal it coats, so it's not
| easy to wear it away.
| blackfawn wrote:
| Gold electroplating can utilize some relatively nasty
| chemicals such as cyanide and cobalt but some ways are more
| safe than others. You could more easily and inexpensively
| nickel plate it with household materials (and a nickel
| plating layer is often used as a flash layer for gold plating
| anyway.)
|
| Simply tinning the copper with solder would likely be the
| easiest option although I couldn't say how durable that would
| be against contact wear over very long periods of time. I'd
| suspect just as durable as nickel or gold plating would be...
| jstanley wrote:
| I wasn't suggesting I'd gold plate it myself, I meant I
| could just buy gold-plated wire, as long as it would be
| sufficiently durable.
| jackyinger wrote:
| Yes, hard gold plating is pretty durable. Take a look at
| the plating on PCIe card and DIMM contacts. Or just about
| any high quality connector.
|
| Switches have an advantage over these connectors in that
| they touch rather than slide. So wear and tear is much
| less of a problem.
| ezconnect wrote:
| Search google for optical keyboard switches, they are easy to
| 3D print. They have clicky designs and just sliders for
| quieter operation.
| m0xte wrote:
| Best to buy gold plated wire off the shelf for your design.
| Solders nicely as well!
|
| I played with gold electroplating pens but they are nasty.
| pehtis wrote:
| Gold plating wont cut it. It is a very thin layer of gold
| around the copper and it would wear out pretty fast. I'd
| recommend bronze.
| russdill wrote:
| Might give more flexibility to move to optical sensing and
| avoid the contact issue entirely.
| jstanley wrote:
| It would. I think a common option is to use magnets and
| hall effect sensors. If you use an analogue hall sensor,
| you can even make an "analogue" switch that can have a
| different effect if you push it just a little bit compared
| to pressing it the whole way down.
|
| Neither of these satisfy me, because in my eyes if you're
| using an off-the-shelf sensor of some kind, you're not
| really making a switch, you're just putting a little
| mechanism around another type of switch. Making the
| contacts out of cheaply-available material is important to
| me, although it's hard to really articulate why.
|
| I'm trying to do this from as close to "first principles"
| as possible.
| outworlder wrote:
| We need to stop at some point though. Do we need to make
| our own wires? That's surprisingly difficult to achieve.
| eknkc wrote:
| Would it be hard to make a buckling spring switch? You'd
| need to use a pre made spring but that does not feel like
| cheating :). Those switches have a fantastic feedback and
| sound.
| Sephr wrote:
| Unfortunately, some optical key switch designs may be
| patent encumbered: https://aimpad.com/patents/
| chrismorgan wrote:
| I wouldn't worry about those ones at least.
|
| I read through the claims of the US patents, and they're
| essentially describing "turn the arrow keys into a
| joystick". US8717202B1 explicitly limits the mechanism to
| a light-and-mirror sort of arrangement (thus, optical
| switches). US8922399B2 is a broadening of the former
| patent, removing that limitation (which weakens it a lot
| because it's not describing a concrete implementation but
| an abstract idea), and thus I _think_ it would be
| claiming other forms of analogue switches (e.g. magnetic)
| too. Either way, there are a number of products on the
| market that, if would be infringing these patents (unless
| their manufacturers licensed the patents).
|
| Besides all this, I don't believe _individuals_ need to
| worry about patents if they're doing things for
| themselves only.
|
| But beyond that, I would be quite happy to ignore the
| Aimpad patents because the concept was not novel, and
| prior art exists.
| https://www.youtube.com/watch?v=gEwDImE0DU4 was in 2012
| and I haven't gone searching any further. Taking the
| broader '399: the project in that video is, I believe (I
| haven't watched much of it, more just read a few comments
| about it and skimmed it), prior art for claims 1, 3, 5,
| 6, 10, 11, 12, and maybe others. For the rest, claim 2 is
| a supremely obvious extension of claim 1. Claim 4 is
| obvious and shouldn't be patentable anyway. Claim 7 is...
| "what? how else could you possibly do it?", _viz._
| obvious. Claim 8 is obvious (as in, if such noise is a
| problem, of course you're going to do this, it's been a
| standard technique on input devices for many, many
| years). Claim 9 is stupid ("slap the rest of the keyboard
| on it"). I think there's a good chance you could get the
| patents cancelled (that is, without waiting to be sued
| and getting a court to rule) if you wanted.
|
| (Although I wrote a fair bit of detail here, I'm in no
| way expert on patents. I've just picked up a few things
| over the years from public news and reading, when related
| things have interested me. Do not trust my conclusions
| here to reflect how USPTO, courts, or any other relevant
| bodies will look on things.)
| delgaudm wrote:
| Inspiring! This would be an awesome punch-and-roll macropad for
| voice actors... well, this particular voice actor anyway. I
| currently use a 10 key pad with tape covering all but the three
| keys I want to press.
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