In our second weekly round-up of the Perpetual Testing puzzles we've been playing, you'll find a pair of elegant testing chambers--one little, one huge and twisty--and a terrific proof of concept for time travel, Aperture-style (the latter is built with the Hammer tools rather than the Perpetual Testing kit). Enjoy!

Download this week's tests from the Steam Workshop:

Expendable Human Launch Vehicle by ceski

Levitation Experiment by Friction

DaMaGepy's timetravel concept by DaMaGepy

Have you made your own test chambers? Seen any you think should be featured? Let us know in the comments below, or tweet us @gamespotuk!