print in .2 with 100% infill. use supports for all touching buildplate.
here is the new prop which will work with a 8mm to 8mm coupler. This one to be precise. http://amzn.to/2lBM8ge2
You’ll use 2 x m4 socket head bolts to secure the prop through the coupler and into the shaft, as well as also 2 of the provided grub screws to secure the coupler to the shaft. Best to still file 4 flat spots onto the shaft for each of the 2 m4 and 2 grub screws.