Footprint with a board notch

(Disclaimer: I looked, but if this is a FAQ that I missed, please let me know :slight_smile: )

I am trying to use a Samtec ERM8 edge mount connector in a design. This connector is keyed on the board side and requires a notch in the board’s edge to correctly seat.

Screenshot from 2021-11-07 18-07-11 scale annotate

I’ve tried edge cuts in footprint (yeah, I know), edge cuts on the board, and all I ever end up with is this:

image

I’ve gone through the edge cuts in the board, “traced” the outline of this notch (by opening the board outline to make a gap and then using lines and arc to form the notch), checked that all edge cuts are snapped together correctly and not leaving gaps. Yet, I don’t get a notch.

What is the correct way to do this? Pointers, well-placed whacks to the head, all welcome.

Thanks,
Christian

How about “I have no idea”? I have not bothered with 3d since I used Autocad in DOS in 3d to design my electronic workbench about 25 years ago.

I had a popup issue and couldn’t download the footprint from Samtec.

But looking at the needed slot, doesn’t the slot need to go to the edge?

Maybe something like this:

If so I would just modify the board outline (aka edge cuts)

I guess the smaller part of the cutout may be optional, I just saw the locking feature in your 3D.

There must still be some problem in the outline graphics. Can you copy the Edge.cuts layer to a new project (or delete everyhing else) and send it here?

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Christian,

It looks like the footprint has an edge with a notch already existing in the Edge.Cuts layer. These Edge.Cuts are an open shape. The 3D viewer has problems resolving open shapes.

Options:

A) Save an edited version of the component with nothing in the edge cuts layer and make the cut in your board yourself. [J1 in image] Probably the preferred method.

B) Save an edited version of the component with a closed shape for the Edge.Cuts and use that. This will cause a problem if that cutout overlaps with your board edge. Also, if you place it too far from the edge you will get a hole rather than a notch. [J2 in image] This could cause problems in manufacturing so many not be a good idea.

notches

Doug

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fairly simple to do it in a Footprint… have done quite a few of them and always works. But, we all have our preferences…

Here’s an image of something I previously posted that may help…

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You need to think about manufacturability. Inward cuts with square corners is a no-go (unless you want to pay extra for laser-cutting).
The PCB manufacturer cuts the PCBs with mill cutters in vertical spindles, and cutters are… round.
If you strictly need to fit in a rectangular piece to your PCB, use “Mickey Mouse Ears” instead.

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Thanks everyone. super helpful. Got it to work and went with the approach in A) above. I had been trying to figure out a way to do J2 and never could get it to line up just right.