Catapult Roller Coaster (Three-layer track)

The two-layer track catapult roller coaster model I released was quite popular. This time, I increased the track to three layers, which was not easy. First, the printing difficulty increased. To get a relatively perfect track, I tried many methods and finally chose to cut it in the middle, print it in two halves (upper and lower), and then glue them into a whole. Because the bonding surface is relatively large, do not use fast-drying glue; use slow-drying glue to facilitate adjusting the bonding surface to achieve a seamless fit. After aligning the joint, I pressed a heavy dictionary on it and removed it after several hours of firm adhesion. The second problem is that after lengthening the track, no matter how much the rubber band was stretched, the printed ball could not complete the entire course. Finally, I switched to steel balls with a diameter of 8mm or 10mm to pass through all three layers of the track.