I made a macro keypad with 3D-printed switches
incoherency.co.uk
incoherency.co.uk
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.
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...
Switches have an advantage over these connectors in that they touch rather than slide. So wear and tear is much less of a problem.
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.
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.)
I played with gold electroplating pens but they are nasty.
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!
I can use microcontroller to read the measurements and want to dynamically change the puller roller speed. (It's a geared down stepper motor)
Pinch roller (puller) is very simple, it uses steel rollers which have sandpaper pasted (with epoxy) on it for gripping fimament - it can pull with force of 10kg before it slips.
I want to achieve tolerance range of +/-0.02mm in diameter
The way you've posed the system, my gut feeling is that your problems are going to come down to reaction time. Once a problem manifests in the system, how quickly can you a) detect it; b) react; and c) have that reaction take effect?
There are three things I'd look at. The first is to make sure the entire path of the plastic until it has set is tightly temperature-controlled. You can't have breezes varying the temperature of the plastic before it enters the bath, so you want a PID-controlled warming tube to control its descent into the bath. Similarly you need to control the temperature, depth, and turbidity of the bath so that the length of time the plastic is less-than-fully-solid is tightly controlled. If you do that, you've got a chance that you've controlled the physics of the filament well enough that quick deviations will be damped out, and slow drifts get picked up by the micrometer.
The second is mounting the micrometer as close to where the filament enters the bath as you can get it. That's the point that's as close as you can get to where the plastic's frozen and the thickness is determined, so there's as little lag as possible between where you're measuring and where you're having an effect. That will let the system react to much faster deviations than it would be able to otherwise.
Third, I'd make that bath as short as possible. The length of filament hanging in the bath will act like a spring, so when the rollers speed up to try to thin the filament out, that acceleration will be blunted as the filament lifts up into a shallower catenary. You can compensate for this in the control system, but it's better not to have to. In fact, if you could get rid of the need for a bath by instead rolling the filament immediately onto a chilled metal roller close to the extruder die, that might open up other possibilities, but that ends up baking stresses into the filament which you might not want to deal with.
It's a nice concept but the design of the switch doesn't intend this project to replace your keyboard.
A nice design nevertheless :)
Still. Why would you want to print your own switch mechanism?
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.