These are some highlights of my Skewb Square-Antiprism Build.

I had already seen a 2x2x2 square-antiprism and I wanted to tackle the same shape with a Skewb basis. I knew it would be a painstaking process to arrive at a tidy puzzle.
I started to calculate some angles and measurements, but then I decided to use Google Sketchup. This is a 1:1 scale model.

I thought about a slightly truncated version (another time maybe)

Then I worked out the skeleton.  I really enjoyed messing around with these models.

From these two models I was able to take the angles of all the internal and external pieces I needed to cut. I also took length measurements but only as a starting point - as I made the first of each piece I was able to get actual measurements.
I transferred the angles onto various reference cards which I used to mark out each piece.

I made some card extensions to get the feel for the shapes. There are three extensions each used four times.

The first step in the actual build was to establish the antiprism shape with these top and bottom corner extensions...

... and next were the internal surfaces of the antiprism corners.

I made the four face extensions as separate units - each with its own base but without the outer skin. Each was glued on using thin card spacers to centralise them between the corners.

All that was left was the "cladding"... I had made the diagonal struts very slightly oversize and was able correct any errors in angle or offset by filing. I glued strengtheners into the larger cladding pieces.

Each outer piece was hand fitted to get the best outward shape.

Finally the stickered puzzle...
Stickered
Stickered2
Scrambled

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