Mesh failed on torque study of hollow drill bit
I am fairly new to simulations and was having trouble determining the maximum amount of torque my drill bit could handle. It is manually turned by an 18.3 inch long handle attached at its midpoint to the hollow bit which is 16 inches long. My overall goal is to allow for a 32 inch long bit turned by a 34.3 inch handle that can withstand the maximum amount of torque applied by the average human on the handle. The biggest problem I ran into was creating the meshes which failed along the handle. I attached an image of the tool in use and the files for reference which are also available via grab cad titled Increment Borer. The file to open is called "Increment Borer (open)" in which one should suppress the sub assembly called extractor to avoid unnecessary complications. I am also not sure about what fixture to use and what faces to select when applying the torque.
Reference Image of tool: https://www.forestrytools.com.au/userfiles/Haglof%20borer%203.jpg