I have been looking over the new motor mounting hardware for both the Chiphua and the drill motor. We have actually done similar designs in the past and have experienced some failures. I wanted to voice my concerns and see if anyone else either shares them or can debunk them.
Drill motor shaft coupler:
Looks like this coupler screws onto the end of the drill motor shaft and is retained by the left handed screw. We did this design in 2000 and sheared the head off the LH screw in every match. I hope I am mistaken about how this design is supposed to work and wonder how much testing has been done.
Drill motor and Chiphua couplers key ways:
I am concerned that both couplers are made out of aluminum. We had a coupler on a part that was not as loaded down as the drive system will be. Using aluminum and 1/8" key ways (without a set screw to retain the key in the key way), we ripped out the key way after several uses. Our key way length was 1/4" and these are longer. HOwever, they will experience higher loads. We remade the part out of steel and had no problems.
Andrew, Team 356