Sep 14, 2009

Two types of homemade balance scales from recycling

We've had a bunch of recycling and craft stuff out in the kitchen 24/7 since the beginning of last week, and so lots of random bits and bobs have been made by both me and the kids. I put my back out and so many things have gone by the wayside the last few weeks, including the blog. Hopefully I will pick up steam again now that I'm feeling better. I think it was Thursday that we experimented with weighing things.

First I used three BBQ skewers, a drinking straw, a cotton reel, two empty pots of apple sauce, four old popsicle sticks, some string, a coffee stirrer, a little bit of styrofoam, a cardboard box, four plastic beads, and a few wooden beads that were lurking around to make a table top weighing scales that the kids could put together and take apart themselves. Here are the parts that I made for the kids to fit together.




The poles go through the cardboard box, with the beads being underneath to hold it steady. Then the two straws with the bamboo skewer glued into them are threaded through the center of the cotton reel. Then the two straws are fitted over the two poles, so that the contraption that is glued around the cotton reel pivots on the BBQ skewer. Then the pots are hung on either side (they are held on by hooking the string over the green plastic beads). I could have made it more sturdy, but I wanted the kids to be able to build it, take it apart, store it flat and build it again later.









We just used what we had handy, but there must be a bazillion different ways to make a simple device that you can compare the weight of two things with. The little red coffee stirrer with the styrofoam arrow made it easier for the kids to see which was heavier when it was a close call between the two weights.

I provided the kids with a bunch of different objects to try weighing, some small and heavy like coins, some larger and lighter like corks. It wasn't long before they went off to find other things they could put in the scales as well, like small plastic princesses and toy animals.










Once they had played with that one for a bit and we'd tried a few different activities with it, we set about making a larger scales that could hang in the doorway. This one was even easier to make. All we used was a plastic coathanger that had hooks on either end, a wooden bead as a weight on a string to always mark straight down. Then I glued on a bamboo skewer with an arrow at right angles to the bottom of the coathanger, so that it would point to either side as the coathanger pivoted. We hung two cardboard strawberry punnets on the hooks at either end of the hanger.



The kids played filling the buckets with various stuff to see which was heavier.



Later that night I figured why not make it into a proper game, so I got out some larger matching buckets to hang on it and drew a little dial that could be threaded over the weighted string that the wooden bead was hanging from. I had to cut the bamboo pointer a bit shorter to read the dial. It wasn't going to be accurate to read for real weight measuring units because the dial was too low for where the scales were pivoting from, but the kids were able to see who's bucket was heaviest and how many "points" they had won. Notice that because the dial is below the pivot point the pointer points to the lighter side, hence colouring the sides to match the buckets, so the kids could see who had won more easily.





If I was doing this again (and we probably will) then I'd loose the wooden bead thread and instead thread a dial onto the string that the hanger was on, so the center of the dial is where the hanger pivots from and have the pointer pointing upwards. That way the pointer would point to the heavier side and also if you had proper weights then you could calibrate the dial (with older kids). Kinda like this...



Anyhoo, they still had a tonne of fun with it and discovered that wooden blocks are infact heavier per unit volume than barbies. Barbie is not as dense as wood! I still don't know whether she is as thick as two short planks though (have I just confused all the Americans reading with that one?)

24 comments:

Inna D. said...

Great idea! I think my kids will love it. Thanks for sharing!

Vacskamati said...

You're awesome!! That's a really fantastic idea (again.. :D)!!

KylieM said...

these are so cool! TOTALLY love your ideas .. school holidays are coming up, and I can just see my boys getting into the scales!

Linda B said...

You are amazing!

M for Short said...

Awesome, awesome, awesome. You have quite a talent for making the simple things fun. I did get a kick out of your non-American English :) toss-ins like 'cotton reel' and 'punnets' - spools and baskets to us Yankees.

Christine at Origami Mommy said...

This is such a great idea! Thank you so much for the step by step tutorial. I can see us trying this sometime soon. Educational and fun at the same time.

Sherry said...

Great ideas! So cool that is it all from recycleables too!

LiEr said...

Genius! Those amazing scales. The callibration! The way you stabilized the supporting posts - so smart. I am always so in awe when I read about the newest invention the filth wizards are enjoying. Funny pot-shots at Barbie, too. I read your posts feeling quite at home with the terminology you use - I didn't even realize punnets and cotton reels weren't American till I read M for Short's comment. Do they say "bale of cloth" instead of "bolt of fabric" in the UK, too? No one says that here, although that's what I think in my head every time I am in the fabric store.

LiEr said...

Sorry - didn't really mean pot shot. Thought it sounded a bit off, so went and googled the meaning and argh.....! So totally not what I meant. Sorry about that.

Valerie @ Frugal Family Fun Blog said...

I am so excited to try this! We have all the materials on-hand because I save just about everything for our "Invention Kit". I especially like the doorway scale. Brilliant!

Native American Momma said...

Wow you got all kinds of ideas once you started.

Mari said...

Very serious scientists!

Maiz said...

way cool! i'll definitely try this!

Liz said...

Oh how fun. My son will love this!

K said...

I don't have my own kids, but I do have a classroom full of them, and your ideas are great! Plus, your containers for organizing are clever. :)

Rachel@oneprettything.com said...

Wow, those are wonderful. Really, really creative! I also love your gift bag robot costume from awhile back. Heather of Dollar Store Crafts emailed me about it. It's genius! I'll be linking to it in an upcoming Costume Roundup. Thanks so much for all your fantastic ideas!

Jen said...

Very cool! My seven year old was just trying to make a scale the other day with recycled materials. I love the ideas that you posted. I can't wait to show her.

Jen
Creative and Curious Kids!
http://raisingcreativeandcuriouskids.blogspot.com

Heather said...

This is wonderful!! I like that we have everything around the house to make this. Great idea!! Thanks for sharing.

Karin said...

Glad I remembered this post today when we wanted to make a quick scale. I think I'll be posting a picture on my blog later this week. We made the clothes hanger version, though the first one you made seems really fun too. Just didn't have all the stuff on hand and wanted immediate results. Anyway, as always, thanks for posting this!

Ylime said...

You are fantastic! I love this idea!! I've listed it in a Spring Break roundup on my blog, The Handmade Experiment. I've got tutorials on things to make and things to bake and a couple of cool etsy artists for things to take this spring break. Come on over and check it out and thanks for the inspiration!
http://emilyflippinmaruna.wordpress.com/2010/03/08/spring-break-week-things-to-make-bake-and-take/

Janice Chuah Education Blog said...

Chance upon your blog while preparing a lesson on weight. What a lovely idea! Your kids are so lucky to have creative parents.
Janice from Singapore
www.teach.janicechuah.com

BadgerGrrl said...

Thank you so much for your page on homemade scales!!!

alavare said...

Great! Perfect for a quick demo during my library story time. I'll probably try something more like the hanger--so easy to set up.

Molly T. said...

Thanks, I love your recycled scale ideas. I've been wanting a scale for my 4 year old class. Now they can build it themselves!!