While testing the function of the seed collection disk, it immediately became clear that circular indentations were not the best choice for collecting seeds. My thought was that a circular indentation would allow for the seeds to be collected in any orientation. Unfortunately, it also allows for multiple seeds to be collected at once.
Another problem I discovered was that the printing orientation of the seed collection disk matters greatly. The disk has some fingers that will be clamped onto a drive shaft to ensure the disk rotates under the seed hopper as the entire seeder apparatus is pushed forward. When the disk is printed with the fingers oriented upward, the grain of the material runs horizontally and the fingers have little resistance to breakage when they bend to the side.
I redesigned the indentations to be ellipsoidal shapes and printed replacement disks with the clamping fingers oriented horizontally. The result was a set of disks which collect the seeds better and have clamping fingers with greater springiness.
Unfortunately, the disks are much rougher in texture due to the difficulty of printing a circular cylinder as a series of horizontal layers. The rougher texture probably won’t matter, but I won’t know until I test the fully-assembled device.
