this is another version of the Ice spider i designed in 2008 see youtube: http://youtu.be/JdK3fKasYLQ now i designed one with 3 chisselsblades for al of you guys with a 3d printer https://www.flickr.com/photos/stijgerart/15696521907/in/photostream/ and ice of course this one is printed on a ultimaker 2 the blades i made custom with holes in it to screw on the botom of the gear rods, ask/mail for questionsyou also need some rods 8 mm steel to join al the gears also 2 rods to join the stam for adjusting the gears aprox 60 mm eich also you need 6 Rampa bolts, i included the file blade example so you can mabe lasercut a piece of toolsteel and sharpen it or print it to use it as a stancel if you have to cut it yourself. i trace it on a old circular table-saw-blade (very good steel) and did the holes with a plasma cutter. they also work in the snow!