Step 2: Materials and Tools
The choice of the four tubes is really important. They have to fit in eachother, with not too much space between them, and also not too little(they still need to be able to move in eachother.) The two outer tubes are an exception to this, they may fit real tight. I have the outer tubes as PVC tubes, I think that's the best choice, and the inner two tubes I have in metal. The second smallest tube doesn't need to be in metal, but the smallest is better in metal, I think. That is because we will hammer 6 nails through it, which need to stay in that place. That's why we solder it from the inside, to that the nails stay in place. you could use a PVC tube for the smallest tube, but then it better have a thick frame, for the nails. These nails are so important because they are the tabs that go through the notches on the rings. They may not break.