Handrail Clamp keyhole

Emphasis has been on printing without support material. So that no time has to be spent on the removal of support material and post processing. Astronaut time will not be charged by additional work.

Clamping force is distributed over several teeth, instead of on one snap edge. This enables them to be made smaller instead of one large clamping edge. Backside provides a spring action which provides tension on the teeth, and also increase friction with frame. And this is also a prevention against slippage.

Compactor and stronger design version was a second point for improving this design. This is achieved by moving the slot to the side of the rail. Structural strength is added by capping off one side of the bolt slide. Bolt can still be added from the other side.

Material usage. There are lots of different infill patterns that you can use, and at different densities. Each pattern has a tradeoffs between weight, strength, printing time. Difficult to estimate at this time.

https://www.nasa.gov/centers/marshall/news/nasa-selects-winning-space-station-handrail-designs-for-grabcad-challenge.html