What is the max size USB mini connector (on the cable side) one is likely to encounter?

It is my understanding that, retrograde though it be, USB Mini is something of a de facto cable standard in the MX keyboard world, especially when it comes to custom cables.

I’m working on a design that will have a USB Mini port on it and I’m trying to figure out how large to make the hole that accommodates the connector end on the cable. I know these are oftentimes made as custom parts that have shrink-wrap on the ends as a kind of hand-made custom strain-relief bushing, so I can’t necessarily just follow the USB spec. Can anybody provide me with any guidance on how big I should make my port hole such that it can accommodate the largest (plausible) USB Mini cable end size?

On the Heavy-6, I used 12.2mm x 9mm. I haven’t heard any complaints about people with cables not fitting, but then again I figure most people there are probably just using the stock FC660C cable, so it may not be representative.

Thanks for any help/insight!

I may be able to measure the sizes of my mini USB cases come Monday when I will have access to calipers again, I’ll let you know!

Any and all data points would be welcome!

I measured the USB mini opening on a few of my cases & the average was 14mm wide by 10/11 mm tall on them.

Thanks! Do you remember what size the largest was?

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NP, the 14mm by 11mm was the biggest I measured so far. Ill check some more of the cases I have once I get home! :+1:

Ok, so I measured all my cases that use USB mini on the PCB & here is what I came up with.

  1. RedscarfII+ ver. C - 15mm wide, 10mm tall
  2. ADK64 - 14mm wide, 11mm tall
  3. Clueboard - (aluminium) 14mm to 14.5mm wide tapered smaller on the bottom, 10mm tall
  4. Clueboard - (acrylic) 11.5mm to 16mm wide tapered smallest on the inside, 12mm tall
  5. Leopold FC660C - 12mm wide, 9mm tall
  6. Leopold FC660M - 15mm wide, 9mm tall
  7. NIU mini - 14mm wide, 10mm tall
  8. ACR60 - 10mm wide, 6mm tall
  9. Sentraq 60% sandwich case - 10mm wide, 11mm tall
  10. KBDfans heavy aluminum case (Lambo clone) - 10mm wide, 6mm tall
  11. XMIT HE KB ver. 1 bamboo case - 10mm wide, 5mm tall

Most of these cases are setup so that the USB mini cable doesn’t have to fit in up to the sheathing, but other than the smallest ones they would mostly accommodate stock USB cables with thicker plastic housings around the mini connector. I measured a bunch of those also just to see what they average & 10mm wide by 6mm or 9mm tall are what the majority of them measure. Not sure if that’s a standard or not cause I also have few bigger & smaller ones, but most generic plastic USB mini cables I have came out to those two measurements. Hope this info helps some!


Thanks so much @Rob27shred. This was enormously useful!

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No problem, glad I could help!