🇺🇦 haxadecimal 🚫👑Apr 3

If you want Cherry MX keyswitches for future use, you might want to stock up. Cherry announced last year that production was moving to China, but today Mouser Electronics sent me an obsolescence notice for Cherry MX Blue.
:-(
#MechanicalKeyboard #CherryMX #CherryMXBlue

EDIT: sorry if I caused any alarm. As several people have informed me, just replace the MX1A prefix with MX2A.

Show threadMark J. BlairApr 4
@brouhaha Is there any remaining justification to buy real Cherry MX switches instead of one of the many less expensive knockoffs? For that matter, was there ever a justification?
Show threadResunaApr 4

@NF6X @brouhaha

Personally, I prefer any of the Outemu silent tactiles.

Show threadMark J. BlairApr 5
@resuna @brouhaha I had not heard of that brand before. I'm planning to use some Gateron silent brown tactile switches in a Color Computer 3 keyboard upgrade.
Show thread🇺🇦 haxadecimal 🚫👑Apr 5
@NF6X @resuna
If you make a keyboard PCB for the CC3, I'd like to buy one.
Show threadMark J. Blair
@brouhaha @resuna Cool! I’m still debating how to tackle connecting it to the computer. I don’t find any suitable pre-made flex cables available that would fit. How would you feel about desoldering the flex receptacle on the main board to replace it with a pin header?
Apr 5 at 8:54pmWeb
Show thread🇺🇦 haxadecimal 🚫👑Apr 6
@NF6X @resuna
Well, I'd prefer to be easily reversible, but it wouldn't be a disaster.
Do the cheap PCB companies in China not do cheap flex circuit? I haven't had occasion to look.
Show threadResunaApr 6
@brouhaha @NF6X you can get pre-made flexible flat cable and just have an adapter on your PCB.
Show threadMark J. BlairApr 6
@resuna The problem is that I do not see anybody stocking pre made flat flex cable jumpers with the pin count and pitch to match the flex socket on the CoCo motherboard (16 pin, 100 mil pitch). Thus, this discussion mod modifying the CoCo motherboard. The raw cable stock appears to be available, but I don’t ’know about stripping the ends as a home player. It’s usually done with a laser, I gather.
Show threadResunaApr 6
@NF6X I just repaired a keyboard where somebody had screwed up a section of flat flexible cable and there are an amazing number of options online for straight through or crossed flat flexible cables with 4 or 5 connectors on up. It can't hurt to look. Also, I managed to get a connection working by scraping the end of the cable with a pen knife and sticking a bit of heavy duty duct tape on the back, when I was waiting for the correct cable to be delivered.
Show thread🇺🇦 haxadecimal 🚫👑Apr 6
@resuna @NF6X
The one for the Color Computer keyboard is very coarse pitch compared to the stuff made now. Maybe 100 mil pitch? I haven't looked at one in years. It seems unlikely that there's anything suitable off-the-shelf.
Show threadResunaApr 6

@brouhaha @NF6X

Molex advertises 2.54mm pitch FFC on their site.

I think you could trim this cable to work:

https://www.molex.com/en-us/products/part-detail/211000012

Show threadMark J. BlairApr 6
@resuna @brouhaha The same page shows that 0 are in stock, samples are not available, and the minimum order quantity (MOQ) is 1000 pieces.
Show threadResunaApr 6

@NF6X @brouhaha

Oh bother.

Show threadMark J. BlairApr 6
@resuna @brouhaha Yup! If this was a 0.5mm or 1mm pitch FFC then there would be tons of options available in single quantity. I don’t think 2.54mm pitch is commonly used enough any more for distributors to stock the pre made cables.
Show thread🇺🇦 haxadecimal 🚫👑Apr 6
@resuna @NF6X
Cool! Thanks for finding that!
Show threadMark J. BlairApr 6
@brouhaha @resuna They do make flex circuits, but I don’t know how cheaply they could be made in small quantity. It’s worth looking into.
Show thread🇺🇦 haxadecimal 🚫👑Apr 6
@NF6X @resuna
Let me know. If it's expensive but not insanely expensive, maybe we can come up with a joint venture or something.
Show threadColin McMillenApr 6
@brouhaha Apparently JLC do those and they're about the same price as standard PCBs. @NF6X @resuna
Show thread🇺🇦 haxadecimal 🚫👑Apr 6
@colin_mcmillen @NF6X @resuna
Do they offer lamination of a stiffener for the connection end(s)? I know, I'm being lazy. I should just look it up myself.
Show threadMark J. BlairApr 6
@brouhaha @colin_mcmillen @resuna I took a lazy peek at PCBway this morning, and it looks like it might be practical to make the flex cables in small quantity. They do appear to offer stiffeners. I am not familiar with JLC's offerings, but I assume they're pretty similar.
Show threadMark J. BlairApr 6
@brouhaha @colin_mcmillen @resuna I'm not sure if a stiffener will be necessary on the end. If I recall correctly, the mylar tails of the CoCo 2/3 membrane keyboards do not have stiffeners. I'll take measurements when I have a chance.
Show thread🇺🇦 haxadecimal 🚫👑Apr 6
@NF6X @colin_mcmillen @resuna
Remember that when you remove the FFC from the socket, insert a very thin shim on the contact side, to protect the exposed cable conductors, so that the socket contacts don't scrape them.
You're likely already fully aware of that, but I learned it the hard way back in the late 1980s with a very expensive to replace flex circuit.
Show threadMark J. BlairApr 6
@brouhaha @colin_mcmillen @resuna My memory was incorrect. There is a stiffener for the final inch of the mylar tail. The mylar thickness is 3 mils, and the stiffener increases the thickness of the mating end to just under 16 mils. The tail has top side contacts, which face the rear of the CoCo when plugged in.
Show threadMark J. BlairApr 6
@brouhaha @colin_mcmillen @resuna
Show threadMark J. BlairApr 6
@brouhaha @colin_mcmillen @resuna Incidentally, this weekend I finally tried printing with TPU filament for the first time. One of the rubber washers on the rear keyboard mounting posts had crumbled, so I printed replacements for both of the washers. Everything worked out well. The only complications were me fumbling about because it was my first time using the AMS bypass path in my Bambu X1C, so I fumbled a bit with both the printer and the slicer.
Show threadMark J. BlairApr 6
@brouhaha @colin_mcmillen @resuna I assume that I may find that the grounding fingers which normally contact the keyboard's bottom plate may interfere with the sockets on the bottom of a hot swap mechanical keyboard PCB. The fingers are just clipped onto the main PCB, and they will pop right off if necessary. It's interesting that they glued the base of the lower left main PCB mounting post preemptively. Maybe they were discovered to be a weak point that broke in shipping?