I bought two concrete tubes. One I did not cut; the second one I cut so I had two pieces, one 2.5 feet tall and the other 1.5 feet tall. That way, when I placed them in the table, they formed a gradient. On that gradient, I set a long cardboard tube by cutting slits in the top of each concrete tube. I taped the cardboard tube to the concrete tubes to hold it in place.
In addition, I embedded a clear, plastic tube through the two tallest concrete tubes. The clear tube emptied back into the table right next to the smallest concrete tube.
Because this is a vertical piece, I needed to make sure it was secure so it would not topple over when the children grabbed onto it. I taped three rods that spanned the width of the table to the lip of the table. I then taped the concrete tubes to the rods for stability. I also taped the cardboard tube to the lip of the table.
I want to end with a word of caution. If you build an apparatus vertical, the children will go as vertical(high) as the apparatus. Watch.
Going vertical from Thomas Bedard on Vimeo.
Two children climbed up on the lip of the table to reach the highest point of the apparatus so they could pour pellets down the cardboard tube. You may have noticed that when they climbed, they grabbed onto the tubes which tested the stability of the apparatus. The apparatus moved slightly but stayed secure in the table. Would you be comfortable with that? If you would not, build only as high as your comfort level.
Just to be clear, when I build this high, I am making moment-by-moment decisions about safety versus benefits. I do get a little nervous when they climb high, but then I move close enough to gauge how each child is measuring their own risk level. If they are doing a good job of measuring their own risk, then I begin to see the benefits: they are building their strength, balance and coordination in ways they author themselves. All their neurons are firing; they are building brain cells. At this point, the benefits far exceed the risks so I am able to relax a bit and let them climb.