[dav_Oz]

Robert Warden (original author of the paper "Cryogenic nano-actuator" (2006)[0]) did the first prototyping with Lego Technic [1]. From Lego to the JWST, I mean damn, like childhood dreams come true (:

[0]https://www.esmats.eu/amspapers/pastpapers/pdfs/2006/warden....

[1]https://m.youtube.com/watch?v=3WBrqUa_1yk

[beambot]

I'm having a hard time understanding the axial motion from the coarse adjustment. From [0]: The Ball Screw in Figure 9 has a 21 mm range. As the ball screw nut moves up, the housing moves up too -- but then the two halves of the tumbler coupling get displaced in such a way that doesn't seem to support a 21mm displacement. How does the tumbler coupling stay mated? (I feel like I'm missing something obvious?)

[phinnaeus]

Why are you supposing that the two halves of the coupler are moving apart? They are both attached to the moving section

[beambot]

Figure 9 implies that the coupler drives the blue gear (shaft of lead screw).

But let's assume you are right: Then how does the blue gear at top of the lead screw simultaneously turn the shaft and move upwards too?

[Linosaurus]

I believe that everything in figure nine moves together vertically except the yellow/orange ball screw nut and pink horizontal thingie, these are fixed to the satellite.

The sensor and stabilizer on the right side are flexible.

[formerly_proven]

https://www.youtube.com/watch?v=5MxH1sfJLBQ