Easiest way to insert sheet metal into plastic housing

Question

I've been working on creating a mechanism similar to the common Cherry MX keyswitches found, except expanded to a much larger form factor. I'm looking to create similar functionality, where the actuation distance is somewhat earlier than the bottom-out distance by a set margin, along with the haptic feedback with optional click. I looked through the actual functionality diagram offered on the Cherry website, and this is the diagram they had for a Cherry Blue (average actuation force, haptic and clicky).

Overall, aside from pretty tight tolerances and a well-designed set of parts, this seemed relatively simple. However, there was one problem that I didn't know how to address, which was the fitting of the sheet metal (marked in black).

In the diagram, it just seemed to hang in the whole arrangement without any suspension, so it was really odd; I bought a set of them to analyze further, and I could see a similar setup as what they had in the diagram:

But in looking for how the metal contacts were added, it seems like they were just slotted in despite being really rigidly fused with the plastic housing (red dotted line marks where the curve in the diagram was:

Is there any way I could assemble this without any special machinery, as all I have access to is a 3d printer for plastic parts and (I assume) pre-cut sheet metal and other inserts that I could use? If not, is there any way that I could alter this schematic in my own design?

Any help is appreciated, thanks y'all!

Answer 1

It's difficult to determine from the images, but I suspect that the method used to retain the metal portion is similar to that used in Molex™ connectors and related types.

Crimp on connectors abound with a design containing a "barbed" finger protruding slightly from the overall profile. As the connector is pushed into the hole/slot, the barb is forced into line with the profile, but once on the "other side," the barb snaps back into position, preventing removal.

dazmode.com is the attributed site for the image below, but a 404 error results in clicking through for an appropriate link.

Note the point of the arrow marked "terminal" as it points directly to what is termed "locking tab." This specific tool is designed for rectangular holes, others I've used permit cylindrical pin removal.

In your second photo, the white extension angled to the left appears to be adjacent to a rather pointed portion in the diagram. It's possible this is the locking tab. Note that applications of this sort require spring steel, not ordinary sheet metal. Ordinary sheet metal will eventually take a set and remain in an un-sprung position, or the metal will fatigue and fail.