I have been building up a LEGO-compatible robotics building kit for my kids based heavily on the blocks designed by @MechEngineerMike.

https://www.thingiverse.com/thing:2415854

I got my first pass of it put together, and I realized that there wasn't a good way to turn it on and off other than plugging and unplugging the battery pack. So I started with the calibration brick and made it fit a SPDT toggle switch.

This is a 2x4 brick that is a little taller to accommodate a MTS-102 3-Pin SPDT miniature toggle switch. These switches are readily available either on Amazon or Ebay. The switch should be a tight friction fit in the block.

10 x MTS-1023 3-Pin SPDT Toggle - http://a.co/9XteXN0

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