6 mm rod 140 mm long

Didn't want to bother with a metal rod so I printed one instead. 140mm long so it fits 3 lids of small/medium size.

There are two versions (I recommend #1):

1. One version which can be printed with the flat surface towards the sheet. Extend as you wish. Kudos to @Duane for the idea.
2. The other one, fully round, should be printed standing up at slow speed (I've used 50% and 10 mm outer brim). It's possible to extend it up to about 180mm without any major issues. >180mm is not recommended as it gets too wobbly at that height during the print.

Use M3x10 or M3x12 to fixate into position.

Additional part: rod.