For our Family Inventors’ Lab class (a STEM class for preschool and kindergarten age), we have built a fun tool, which encourages the kids to tinker – see my last post for how kids play with a wind tube. This post is about the tinkering process we used to build and refine our DIY wind tube.

We started with the directions from Exploratorium. We ordered from Amazon:

• a big, powerful fan – we use the Honeywell HF-910 Turbo Force. (My colleagues tried using a smaller fan, and smaller hoops to save money, and their version can just barely lift a scarf up and out of the tube. It’s just not nearly as fun as the bigger one. The Kodo wind tunnel uses this Vornado fan, and it’s larger cousin might be a good option)
• 2 14″ embroidery/quilting hoops and
• a acetate sheet  Ours is 40″ tall. You need about 48″ of it. Exploratorium’s directions called for .0075 ml thickness, we used .01. It’s a little pricier but it’s been very durable which is important to us because we transport it to several sites. (Other builders have used 1/32″ thick polycarbonate, but I haven’t found that in large sheets.)

We cut the acetate sheet, and assembled the tube with the hoops. Definitely a two person job. You can clamp the plastic between the inner and outer layer of the hoop, just like you would fabric. We then used clear packing tape to tape the seam. (We also taped over the metal clamps on the hoops, and the edges of the acetate sheet on one end, just so kids wouldn’t scrape themselves while playing.)

Then we needed spacers to lift the tube up off the fan. Exploratorium recommends wooden spacers that you cut a notch in. We built spacers with Duplos and set the tube on those. (You can see them in the videos in this post.) For our family, that worked fine, because it was easy to rebuild them if they got knocked off. For class, I wanted something I didn’t have to rebuild. I found some giant clothespins (like these), which worked great.

When using the tube with 2 – 4 year olds, I need to cover up the fan openings, just in case someone tried to put rocks or beans or coins or something into the fan. (Or fingers, of course. That wouldn’t be possible with this fan design, but it might be with other fans!) I bought 1.5 yards of black tulle with pretty sparkles (like this), and we wrapped it over the fan, tying it off below with a twisted pipe cleaner. The tulle does work great as safety proofing and looks fine, but it does diffuse the air flow from the fan a little, so some of the heavier things that would fly without the mesh on don’t fly well with the mesh on. I remove the mesh when I only have older kids who can be trusted if told not to try dropping small heavy things in…

At home, we just set the tube on top of the fan, but for class, I need to tie down the tube to the fan. Otherwise it’s easy for it to get knocked over and land on someone’s head. (Note: it doesn’t really hurt if it does, but it is mighty startling.)

Exploratorium recommended drilling holes in the spacers, disassembling the fan, and fastening the spacers on with zip ties. We decided it would be much easier to just thread pipe cleaners through the springs on the clothes pins, and loop those down through the fan and back up again (no dis-assembly required) and twist together to tighten. It was easy to do, worked great to tie them down, and is easy to undo later if desired. An advantage to the clothes pins is that it’s easy to clamp the tube onto the fan, then easy to un-clamp it for transport.

I’ve watched countless children age 1 – 10 play with this for hours. The under-one-year olds love just watching things fly up and out of the tube. The two-year-olds love shoving things into the tube and watching them fly. The three-year-olds start to make observations on which items flew best. The four-and-ups experiment with building things, tying things together, trying to put things in from the top, and so on. Some of the parents get caught into the experimenting too, folding paper helicopters and such to test what will fly. The kids play really well together – part of the point of this game is to put something in and LET GO, so there aren’t many issues with having to share something that someone was holding on tight to. They all play happily side by side. They don’t really need to take turns, as it works fine to have four or five things flying at the same time.

Here’s some of the items we have launched. (See some video in our Wind Tube post.) We look forward to more play and experimentation to see what other items we can find or build that will fly well in our wind tube.

Alternatives to our DIY wind tube

babbledabbledo describes building a simple “vortex” by just rolling a tube of poster board and setting it directly on the fan. Kids put a scarf or a balloon above the tube where it gets caught up in the rush of air. Super simple! I like that with our tube, the kids can put the item in at the bottom and see it travel up the tube, but this simple alternative may meet your needs just as well

Kodo Kids makes a wind tunnel that looks fabulous! And I know their materials are very high quality. I’d love to have it, but it costs $450 plus a $45 fan, versus the materials for this DIY tube are Around $140 before tax. [Fan ~$45; hoops $16; acetate sheet $50 ($35 for thinner material); clothespins $15; tulle fabric.]

Or you can buy the science museum version for $13,000.

There is also a DIY wind tube tutorial on Instructables. It requires that you own real tools, which I don’t. 🙂

For lots of ideas for STEM enrichment activities with kids, check out my blog www.InventorsOfTomorrow.com.