Firecracker Launcher

1.5-inch wheels * 4

M3 self-tapping screws

DN15=1/2 inch + DC type DN15=1/2 inch; one snap-fit male and one female pagoda fitting each

One 200mm length of 1/2-inch stainless steel double male threaded pipe

One 1/2-inch internal and external threaded connector (barrel)

One 1.0*25*300 mm spring (slightly long, can be trimmed; half-length suffices for two)

1.5-inch wheels use M6 screws; these can be used directly, or longer M6 screws with nuts can be used for enhanced stability

If you have access to Taobao 88, you can purchase components daily…around ten yuan should suffice

(Future updates will include 2-inch and 3-inch wheel configurations with corresponding pipe lengths)