Science Olympiad Balsa Events Autoloader
CNC files for the frame can be acquired through the f3d file I have posted (you will need to download fusion 360).
Spring:
https://www.amazon.com/dp/B008RGBI0U?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1&th=1
Sand:
https://www.amazon.com/dp/B0791W9MXL?ref=ppx_yo2ov_dt_b_fed_asin_title
Pipe Fitting:
The holes are made for a .5 inch rod (can be bought from home depot). You will need to carve them out a little bit because the rod needs to be a tight fit, so once you print them carve out the holes until the rod slides in with a tight fit. The main pipe is made to fit onto a 2 inch pvc pipe.
Happy Building!