Mechanical NumPad expansion card

I’m currently exploring the possibility of creating a numpad expansion card but I need more experienced people to give me ideas. I will more than likely use hotswap sockets. Are there any mechanical keyboard nerds that could help me.


As opposed to using a USB keypad?

This will be a built in one that uses the expansion card.

1 Like

I feel like this would take up a lot of space on the laptop’s side, probably blocking both of the card slots. Any plans to include a pass through for one of the slots so that you can still have that third card in addition to this pad?

I would be concerned about port durability. I think the “slides” are aluminum, sure, but how much stress do you think they could take? It might need to take two slots to keep stable when being moved, and if it shouldn’t be moved, then perhaps a USB form factor would suffice. This is all assuming it’s “hard=mounted”.

If it’s on a cable anyway, it might be difficult to remove regularly for storage or portability. I don’t mean to tear down your idea mate, but as USB one might suffice for most use-cases…

Yep I’ll do a pass through with some extra ports along with the USB-C.

You shouldn’t “hard-mount” anything larger/heavier than a thumbdrive to a port. Granted, the expansion card provide additional leverage, but I don’t think anything larger than a custom Dpad should be an hard mount.

A custom USB mechanical numpad keyboard would be very nice for accountants (me not included).
Sure, you can have a custom cable ending with a housing that fit in a expansion slot (to reduce clutter). That will be rather clumsy (however not so if the housing can be removed to become a regular USB-C plug)

Did a basic board

I’m planning on adding a second slot for stability and a passthrough USB C port.


I’m wondering, wouldn’t it be better to have the USB-C (male) plug sticking on the side of the numpad? It seems like the board would easily snap with a light smack of the side.

Instead of an expansion-card-merged-numpad, something like this crude ASCII render of a numpad would probably work best, as it can also just connect to the already-made USB-C expansion card:


As a benefit of having the plug on the side, it can be designed to be modular in case it breaks off and needs to be replaced.

I’m worried about snapping. I think the best play would be to have it take up both expansion card slots and passthrough the unused one, providing more stability (and access to that port which would be blocked otherwise!). Of course, that wouldn’t matter if this was only ever used on a desk.

Yeah I think the best bet will be to … get a regular USB numpad.
Having things sticking out the side is not a problem, but things such as the numpad can easily put way too many stress on the connection (even with a full-aluminum dual-slot design) if you, for example, put it in your bag with the numpad attached.

This would provide basically zero stability with how short usb c is. You’d be pretty much guaranteed to snap them off as opposed to the expansion card ports which have rails and are longer.

This would provide basically zero stability with how short usb c is…

Seeing how you’re comparing stability, I could also say the same thing with the current design.

My thought process being: Something longer = something more prone to being easier to snap off.

With the usb c on the side, the design could change the plug to become modular, so it’s easier to replace when it snaps off, as opposed to a broken pcb when you snap off the rails.

Or make it so that it won’t be damaged when it snaps off …

If the keyboard attaches via magnetic connectors (really, spring contacts, held together with magnets), then there is no possible way you can break them since it will be designed to “snap away”. You store the keyboard and laptop separately during transit, and snap it back to the side (of laptop) when you needed.
this actually sounds good, but I think it is just re-inventing USB numpads.