Reddit mentions: The best toy interlocking gear sets

It's not the cheapest of toys, but one I am very glad I got my brother. This set of plastic gears. My four year old brother loves these things. And my one year old sister likes to mess up his creations. I could see a very wide range of ages playing with it. So, while you could get something cheaper, I'd expect this to get a lot of use out of it.
Another thing, this may be useful or not depending on where you're at, goodwill has a website. Shopgoodwill.com. They sell things like bags of marbles or legos. I'm sure there's other interesting stuff too, but that's what's on the top of my head.

If you really want to go into a rotating / clockwork system, you could make the entire dungeon a rotating labyrinth.

For your purposes, I think where you're starting is fine, but I'm not sure I'd use a "1d4 rounds" mechanic. Clockwork means it should be predictable, not random. Also, I'd have some sections move very frequently (more than once per round).

For the predictable part -- allow players to spend a turn analyzing and on a successful Knowledge Engineering (or equivalent) roll they can make a guess as to what will move, when, and in which direction, allowing them to plan actions. They would also get a bonus on dexterity rolls to stay on the platforms -- faster-moving outer sections are harder to manage, right on the pivot point is pretty easy. More importantly, the enemy should know those movements, and use them to his advantage where possible -- intentionally getting on a platform that will move him into range for an attack, and then immediately move him out again after, for example.

That's where multiple-times-per-turn comes in. Holding Actions, or Readying Actions for when platforms move. Put them into the initiative order so they spin all over the place. To ensure the fight doesn't end up static, I'd have nearly every part go into a danger-spot on occasion -- steam blasting out of a pipe, or one end of the platform sliding into a wall, or whatever makes sense -- to ensure the players can't just try to trap the bad guy in one spot and then fight him while ignoring the room hazards.

Beyond that... Platforms should only rarely overlap -- better to have them reverse direction if they would otherwise sweep across an existing platform. That said, if they do go across, you should determine in advance which is above the other, and you run them like traps, tripping people who don't jump them, and allowing people to try to get on / off as one sweeps over the other, and so on.

Gears could be more interesting in general -- look into using board games like Tzolkin or 5th gear or even a kid's gear play set if you don't want to make your own, but having players riding various sizes of gear as they rotate handles the dynamic but predictable element of the terrain changing, and allows for some potentially gruesome hazard-damage using push-attacks into gear-teeth.

Edit: I also strongly suggest they get to traverse it once with just the gears and platforms being the encounter, before needing to revisit the room while also in combat. Especially if it isn't as easily predictable as, say, turning a set of gears once or twice per round.

Man, you just gave me a flashback. When I was a kid there was a toy that was just a platform where you could set gears on a grid like Legos. There were different types and one of them had a crank so you could spin the whole thing to see how they moved. Pretty simple but it kept me entertained as I tried to figure out new ways to make them spin. I'll look around and see if I can find it online and give you the link

Edit: that was a lot easier than expected. Here's a link to it https://www.amazon.com/Learning-Resources-Gears-Gizmos-Building/dp/B00000ISYC

Love that Lego pen holder! was that from a mini-kit, or part of a larger kit?

Nice pen too!

Edit - found it I think - part of LEGO Creator 3in1 Deep Sea Creatures 31088 Building Kit , New 2019 (230 Piece) Amazon - is this right?

For art - this is for my special ed students http://www.amazon.com/dp/B0067QL5GO/ref=wl_it_dp_o_pd_nS_ttl?_encoding=UTF8&colid=29LN64LBT9RGA&coliid=I1EYND1P31H60I

For science - my students would love to learn about gears, build them, and then see them work.

http://www.amazon.com/dp/B00000DMCE/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=29LN64LBT9RGA&coliid=I1QM0GEG4QAFOH&psc=1

Thanks!! Also snagged 75229 for $22.19 (26%)

Do you think the kid's toy gear sets were for Tyler's girls?
here, here

Just build it out of these

Star Flex

https://skoolzy.com/products/star-flex-creative-connecting-construction-kit-for-kids-by-skoolzy-stem-manipluative-brain-building-toy-montessori-games-preschool-kindergarten

In the UK we had Marble Mania

What do you think

https://www.amazon.com/dp/B07BKTYKBG/ref=cm_sw_r_cp_awdb_t1_D.SDCbRKYZP8T

Try one of these bad boys.

https://www.amazon.com/BOHS-Mechanical-Building-Science-Educational/dp/B07HCN1V2L/ref=mp_s_a_1_2?keywords=Toy+fan&qid=1554955886&s=gateway&sr=8-2