Andy
100% agree with all these guys
a flexible joint at both ends is a must and diy props are achievable
you just got to weld it true
and an old trick for when its on the car
if you have a slight vibration put a jubilee clip around the shaft and run it .if no better rotate it slightly etc etc until the vibration goes i have seen up to three jubilee clips used to smooth out a vibration
cheers les g
PS. it wasn,t my welding LOL
