Interested in building one of these as well. I have the means to make these out of sheet metal. Did you find plans or came up with this yourself?
Discussion
I went in with a group on a "Protapod." I set it up about a month ago. #grownostr
Our group ordered like 12-15 and had them freighted in. About 1/2 the price of ordering individually.
I used this pdf as a guide, but mostly I winged it.
The most critical part is the ramp angle of 40 degrees
https://ie.unc.edu/wp-content/uploads/sites/277/2016/03/bsfl_how-to_guide.pdf