I’m looking to find the mating connector for the Alchitry Boards. Ideally at LCSC, so I can incorporate it into a JLC build.
The datasheet from Sparkfun mentions 4ucon and 1660&1661, but digging into that further yields partial info. Is this part available in regular distributors, and ideally not with a Sparkfun part number?
Look at the Alchitry Platinum Planning thread for the upcoming solution to this issue- the new versions of the boards (expected quite soon, possibly before the end of the year) use more standard connectors, and in a more compact footprint.
I got around the issue a couple months ago by using the Br board, where I soldered the female headers onto it, and then set up 0.1” male pin blocks on my pcb to match. Not very suitable for high speed signals but my current needs are just in the 1MHz range, so it works fine.
This was a huge factor in switching to the form factor. The old connectors are from 4UCON (19022 and 19008). They weirdly aren’t listing the 19008 anymore but they’d probably still sell you some. Only issue is their MOQ is 5000. SparkFun is where you can get them in smaller quantities.
The new connectors are widely available. The mating connectors are C424645 and C294544. The connectors on the board are C5338326 and C5254351.
If you can get away with a 1.5mm stack height, the C312960 and C424646 also work.
I wonder, wouldn’t it be cheaper to have 3 identical connectors to reduce BOM instead a smaller one for Control?
Is there a reason to have them different?
Space and cost. The 50 pin connectors are about half the price as the 80 pin.
Oh, ok I didn’t though the price difference could be so much 
Thank you for the thorough info. I’m glad to hear you’re addressing the problem in the future, though it doesn’t solve my problem in the short run. My client wants a board designed and fabbed in a few weeks. We were hoping to have LCSC build the board, but will have to just hand-populate the 4UCON connectors ourselves.