Hello everyone!


I am planning to build an undercutter/bed lifter tractor attachment. The goal is to slide a slanted board 10-12inch (25-30cm) deep into the ground and lift the soil just enough, so that you don't need to use a shovel to dig out root crops such as garlic or carrots. This is how it looks in action:Big Elk Garlic under cutter - YouTube . And a lighter version: Improve Harvesting Efficiency with the Thiessen Undercutter/Bed Lifter - YouTube

These are my dimensions:
3pt-izkopalnik-2 — ImgBB(top link arm isn't drawn)
izkopalnik-mere-international — ImgBB

I am unable to asses how thick should the sidewalls and the bottom lifting board be and which steel is best suited for such applications. Can you help me out? Does anyone have an undercutter on the farm and would be willing to measure how thick the steel is? The one in the video looks 3/4" to 1", not sure what type though.


So my choice is between regular steel and hardened steel. I believe regular steel is marked as S355 or S235, the number 355 and 235 corresponding to the yield strength in MPa of the steel. Yield strength is determined under axial stretching of the specimen and corresponds to the maximal Force per area under which elastic deformation occurs. Hardened steel has yield strength 3-5 times higher than the regular steel. For example AR400 or Hardox 450 steels have yield strength 1187MPa and 1250MPa respectively(https://www.steelwarehouse.com/ar400/ and https://www.ssab.com/Products/Brands...cts/Hardox-450)


Is yield strength directly proportional to how much the steel would resist bending in transverse direction too (as opposed to axial streching)? Because it is nuts to think that 1/4" AR400 would resist more to bending than 3/4" S355 structural steel. Am I reading this numbers correctly?

Thank you for taking your time and answering this question!


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