I needed to make a backing board for a dolly / handtruck as it had a large hole in the middle that bags/boxes could fall through, I happen to have part pieces of hsw already so I figured why not just make it a hsw backing.
The gap is 10mm and uses M3 cap screws if needing to anchor on a bar like in the images.
I used perplexing labs hsw generator to make the ideal size hsw for my needs
The author remixed this model.
Added a 10mm partition board hanger to push into HSW