Gears

I purchased some gear kits from TeacherGeek. They have setup and lab documents available.
We start with the Setup guide that comes with the kit, then I tweaked labs a little (Gear 1 & Gear 2)
Remember there are some cool websites about designing gears
http://www.gearsket.ch/

https://geargenerator.com/

Lakeview Elementary was the first group that wanted to use them and we did a few sessions with them (though part of our sessions was general Q&A about science stuff). They explored and played and we discussed what they found/learned. We didnt get to the Mechanical Advantage Gear 2 lab, but were close and did talk about that idea with most groups.