Posted: Tue Jan 02, 2018 5:52 pm
by jcruddat
Hi Dwain,
Right now I am considering making the shaft out of 4130 chromoly steel and the threads out of some hardened 4340 chromoly steel. This is what was suggested to me by some guys in the discussions I started in the PracticalMachinist and CNCZone forums (http://www.practicalmachinist.com/vb/cn ... el-339531/ and http://www.cnczone.com/forums/machinist ... 4-cnc.html). I am also going to do a simulation in SolidWorks to determine the maximum torque that can be applied without significant twisting or breakage of the increment borer. Your giant burr oak reminds me of some large white oak wolf trees I came across once in Cowles Park, East Granby, Connecticut. I might be interesting to see how old those large trees are in order to determine when last the forest was a pasture.


288.JPG

Large field grown white oak #1




302.JPG

Large field grown white oak #2




Jack