Pop-pop or put-put steamboat made easy for children

Step 4 Coiling the engine

Fixing the tool, for example to a sturdy table surface can help, but can be ommitted.

In addition to the video, here follows a description:
Put the brass or copper tube in the tool as shown in the previous step, with the one end sticking out 9,5 cm (i.e. adjacent to the mark made earlier). Slide a sturdy tube over the other end as a bending assistance, keeping the end at least 1 or 2 cm away from the mandrel/cylinder. KEEPING THIS DISTANCE IS VERY IMPORTANT to get smooth bends and avoid local buckling of the tube. Using the piece of wood and the assisting tube as levers bend the brass or copper tube around the mandrel. It is important to keep the end of the sturdy tube one or two cm away from the cylinder to avoid to much local bending. Try to keep the windings relatively close to each other, but gaps up to about half a cm are still OK. Make four windings, ending up with the two ends of the tube perpendicular to each other (see pictuere). Remove the assisting tube and slide it over the other end, up to about 1 cm from where the tube passes the screw. Bend the tube end 45 degrees towards top end of the tube. Remove the assisting tube and the complete coil. Turn the coil around and slide it back on the mandrel, fitting the other end between the cylinder and the screw. Slide the assisting tube over this end and also bend it 45 degrees, bringing it in parallel the other end. Your steam engine is ready.