Aim for lightness with strength. Two shells should be enough. Rotate so the straight edge is down. Use a brim of one layer and 10-15 perimeters to stick the struts onto the build plate.
These struts were printed in PLA. I would prefer ABS, but haven't solved the shrinkage issue yet. The red wheel is an ABS print that didn't quite finish.
File or scrape any rough edges until smooth. Drill out the axle holes to fit your axles. They are 4 mm diameter in the design.