I should have said I'm an *old* engineer, and we were doing layouts with press-on pads and tape and an Xacto knife. Millimeters were only used for nitpicky optical stuff (and spark plugs).BlindAssassin111 wrote: ↑I am also an engineer, but I tend to prefer mm, but for keyboards it is a bitch using 19.05mm for spacing, so I have to use inches...
You are correct about the spacing, but I was thinking because keycaps go in increments of 0.25U, the spacing would also follow that, which is true for most boards, this is the first exception I have seen. So it was unexpected, but it does make sense when you think about the spacing in inches instead of units. Center to center makes sense, but for layout it is easier to see a spacing than a center to center measurement when just laying out the blocks. I use both but each one has its' pros and cons.
The switches are laid out now, so I just need the locations of the screw holes in relation to the center of some switch...as the board edge is not going to be a reliable thing to measure from. Just use the same switch for each to make my life easier, or don't...if you hate me, lol.
Looking good so far! You might want to check the spacing on the insert and delete for the Plus versions. Those two have the stems centered on the caps, so those switches should be centered at 3/4U and 2-1/4U, not 1U and 2U.
Here's a couple old photos of a bare Gen3 PC board that might be helpful:
keyboards-f2/just-picked-up-an-omnikey- ... ey#p342941
It's interesting to see the alternate switch locations marked "Europe". I've never seen a Northgate with a "European" layout, but it's possible that some were produced.
I'll get you some measurements for the screw holes ASAP, and I'll dig out a Plus and Ultra to make sure there's nothing worrisome on those.