[This is a first pass at a 1/4"-20 mount for an Ablenet Micro Light switch. It currently is having trouble printing in ABS. I will update when we have good print settings, etc.]
AT Switches are used by people with physical challenges to activate devices, communicate and control their environments. Being able to use standard camera mounts (with a 1/4"-20 bolt attachment) is incredibly helpful for positioning.
This adapter is for the Ablenet Micro Light switch - https://www.ablenetinc.com/micro-light-switch
It adds a 1/4"-20 socket by inserting a T-Nut into a channel. This version requires a .6" tall T-Nut (commonly used to mount things in 1/2" plywood. (At Ace Hardware it is the "Tall" or "Long" version in the bin.)
Here's a video on installing the TNuts: https://www.youtube.com/watch?v=_fH-vgqx3uw&t=8s
[UPDATE: I have added support for both 3- and 4-pronged TNuts at heights of 5/16", 7/16" and 9/16" - note that I've only tested the 9/16" 3-pronged]
I have had a hard time getting this to print well in ABS - it tends to droop no matter what orientation you use except round-side up (which causes problems removing the thin support material). It prints great in PLA.
The T-Nut can be inserted with the barbs going into the small slots. Use a long (1"+) 1/4"-20 bolt to pull the T-Nut in tight. We will post a video showing this eventually.
When printing in ABS, take Pedro Ruiz' advice and print two copies (round stem down). That gives enough time for the layer to cool and to not sag and fail.
PLA has no problems with this design