In my STEM enrichment class for kids, during our Simple Machines unit, we do a session on Pulleys. You can learn about the science of pulleys and all our activities in my full post on pulleys. This post is just all about pulley systems you can set up for kids to have fun playing with.
If you prefer your information in text form, read below. If you like videos, here you go:
Safety Note: pulleys should be used under adult supervision, because anything involving ropes creates a possible strangulation risk.
For pulleys, you could use utility pulleys like these, or these Rocari pulleys, with 1/4 or 3/8 inch nylon rope. You’ll need 20 – 25 feet of rope for a fixed pulley system. More for more complex systems.
A fixed pulley. Raises a load from the ground to somewhere up high. Tie a pulley up high next to some place a child can safely stand, like a slide platform, a stair landing, or a tree house. Tie one end of your rope onto your load, then throw the rope up and over the pulley. You pull on the loose end of the rope to lift up a bucket. These systems are super easy to set up.
You can attach a flag to the rope and use the pulley to raise it. Or attach a sheet and raise it up then stretch it out to form the wall of a fort. You can raise a bucket full of water that you’ve punched some holes in, and it’s a sprinkler! You can set up a bucket at the bottom of your stairs where as the day goes on things that need to go back upstairs get tucked in it, and then when someone goes upstairs, they haul the bucket up and unload it.
The classic way to play with a fixed pulley is for one person to be on the ground, and use it to raise things up high to another person. You could attached the fixed pulley to a slide platform or a balcony.
Here are pictures from some fun posts about how parents added fixed pulley play to their backyards for hours of fun for their kids: https://innovationkidslab.com/backyard-pulley-engineering-kids/; http://happyhooligans.ca/a-bucket-and-a-rope/; and http://littlebinsforlittlehands.com/homemade-outdoor-pulley-play-idea-simple-machines/ One of the authors points out that even though it doesn’t really “accomplish” anything to fill a bucket and raise it up in the air, and even though it’s the same every time, kids will do it over and over and over.
Movable pulley. You can stand somewhere high, and use the rope and pulley to bring something up to you. (Good for kids who are playing alone. They can go down, load the supplies, climb back up, and pull the load up to them.) Tie one end of the rope up high, loop it down around a pulley, and back up again. Attach load to the pulley.
Compound pulley. Can move a load over and up (horizontally and vertically.) Requires two pulleys – it’s basically a combination of a moveable and a fixed pulley. Tie the rope up high, then run the rope down through pulley #1 that has a load attached to it, then up through pulley #2, then down to the ground. You pull down to lift the load up.
Here, we anchored one end of the rope to a nail on the wall, then ran it through the bucket handle (we cheated a bit by using the handle as the movable “pulley”) then up over a spool.
With this next one, we used a PVC frame, but you could do a similar thing on a tree branch or a playground structure. Tie one end of the rope to your frame, then down through a movable pulley attached to the load, up to a fixed pulley, down to another moveable pulley, up to a fixed pulley, then leave the loose end hanging down. When you pull down on it, the bucket is lifted high. Kids can lift a load that’s four times heavier than they could lift on their own!
Block and Tackle. There are lots of variants on block and tackle. They use multiple pulleys (and lots of rope). They make it possible to lift heavier things. If you have two pulleys, it takes half as much work to lift something. With four pulleys, it’s one quarter the work. For the simple version, anchor a pulley. Tie the rope to the bottom of it. Run the rope down around pulley #2, then up around pulley #1. Pull down to lift the load up.
A basket on a track. This is a variant on the fixed pulley, where you can get vertical and horizontal movement, as the basket travels up a slanted track, shown in brown. Run the track cord through the handle of a bucket. Then tie both ends of the cord to be your track. It MUST be taut! And be sure your bucket can slide easily up and down the cord. (If desired, you could attach your bucket to a second pulley, as shown, which would glide easily up and down the cord.) Then tie your pulley at the top. Put a rope over the pulley, with one end hanging down (to pull on) and tie to the other end to your bucket. When you pull down on the rope, the bucket goes up. This is the hardest pulley system to set up and make work well. For extra challenge: if the basket is heavy enough, then when the child lets go of the rope, the basket slides back down to the bottom of the track ready to be loaded. It takes a lot of tinkering to get that to work just right. If it’s not heavy enough, the kid on the ground may need to pull the basket back to the bottom by hand.
We used one of these pulley systems on Halloween 2020 to provide socially distanced candy delivery to trick or treaters. We were standing up on the balcony, and could clip an item on a pulley and send it down to the child, then pull on the rope to bring it back up.
The clothesline. Send a load back and forth along the track. Requires two pulleys. Attach pulleys to anchor points. Take a rope and wrap it around both pulleys, then tie it, making one big loop. Clip things on with clothespins, or tie a basket or other container onto it. Then you pull on one side or the other to bring the basket from one end to the other. Challenge: The rope must be perfectly taut for this to work! If it sags, it falls off of the pulleys. (And if it’s really tight, it’s hard for kids to get it moving.) If possible anchor one end on something you can move back to make the rope tighter. If you’re anchoring it between two immovable objects (like two trees), expect to spend quite a while (10 minutes?) on tinkering as you set it up to get it just right.
In this picture, we just had a clothesline that ran between a slide platform and a hook on the wall. It’s much more fun to set it up someplace where kids can access each end of it. They can write a message, clip it on and send it to their other child, who can write a reply and send it back.
Note: the links to pulleys and rope are Amazon Affiliate links, and I do get a small referral fee if you click through and purchase anything.