5 ms·
Those contacts will oxidise almost instantly. From running morse keys for years, you need gold or phosphor bronze.
by m0xte 6y ago
Those contacts will oxidise almost instantly. From running morse keys for years, you need gold or phosphor bronze.
- jstanley 6y agoThanks, I will keep an eye on this. Do you reckon gold plating would suffice or is it likely to get worn away?
- blackfawn 6y agoGold 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 6y agoI 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 6y agoYes, 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.
- mdszy 6y agoGold 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.
- russdill 6y agoMight give more flexibility to move to optical sensing and avoid the contact issue entirely.
- jstanley 6y agoIt 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.
- eknkc 6y agoWould 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.
- outworlder 6y agoWe need to stop at some point though. Do we need to make our own wires? That's surprisingly difficult to achieve.
- nkrisc 6y agoConsidering it's a personal project, one can choose where to stop. Sounds like they've chosen to draw the line at making their own switch mechanism.
- Sephr 6y agoUnfortunately, some optical key switch designs may be patent encumbered: https://aimpad.com/patents/ https://aimpad.com/patents/
- m0xte 6y agoBest 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.
- ezconnect 6y agoSearch google for optical keyboard switches, they are easy to 3D print. They have clicky designs and just sliders for quieter operation.
- pehtis 6y agoGold 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.