robot claw prototype

I've been thinking about building a miniature single-aisle (2d) ASRS, like this:

But simpler, and smaller.  Luckily, DIY CNC and 3d printing is fairly common now and I think i can use a lot of parts from those -- just tipped vertically.

One tricky difference is that instead of a cutting or printing head, I'll need a little grabber claw and I want to minimize the wiring, weight, and complexity -- i was hoping to get away with just one motor rather than something to extend/retract an arm and another thing to pinch/release.

That is: I want something that can reach out, grab something on a shelf, and pull back while holding it.  Then i want to be able to reverse it to put things on the shelf from the claw.

There are a million awesome linkages in the world, but i find them very hard to think about.
https://makezine.com/2015/04/20/understand-1700-mechanical-linkages-helpful-animations/
http://507movements.com/index02.html

I guess the one i hit on accidentally was sort of similar to this, although with different arm lengths.
http://www.mekanizmalar.com/hoekens_linkage.html

My high-tech prototype:


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