draw a rubber finger weeder in CAD. CAD Files Here.
figure out the appropriate polymer for casting (different rigidities are used for different soil types)
cast the fingers in plastic
determine the appropriate hub and shank (depends on the type of toolbar you're hoping to attach this tool to). Source it.
put it together. local manufacturing.
farm/field test and repeat.
This is a cultivating tool which can be useful for many different applications: cultivating tractors (electric and fossil fuel), draft-powered cultivating platforms such as the McCormick Deering New 4 which is commonly used on draft-powered farms, walk behind tractors, etc. However, the dimensions of the shank will be different depending on what platform the finger weeder is intended for. Here are some common dimensions (please help fill in this section as I mostly work with draft).
Draft-power: McCormick Deering New 4: Clamps fit onto 1" round stock, ground clearance is 15-16", total shank and tool length, approx 18"
Farmall Cub, 101, etc: need more info
Allis Chalmers G: need more info
Currently, students at Olin College, Boston, are working on drawing finger weeders in CAD to be cast either at Olin or at SU by other students. Finger weeders usually cost between $500-$1200 per pair and are not manufactured in the United States. There are now some U.S. importers but European companies are the only ones making them, raising their cost.
Our assertion is that finger weeders should cost more in the range of $30-$60 per pair.
KULT Finger Weeder on a rototiller.
European video of cultivation tools including finger weeders.