The Scorpion HK-4035 motors are built with 8mm hardened steel shafts that will last through countless hours of flying fun, but occasionally, on a "Less than Perfect" landing, you may bend or break one. For these occasions, we offer factory replacement shafts for all the HK-4035 series Scorpion Helicopter Motors. Our Motor Shaft Kits include an original equipment factory shaft with the setscrew key-ways already cut, a new spacer washer, and a set of 2 retaining clips. This way, when one goes flying and bounces off the wall while you are trying to install it, never to be found again, you still have another one to use!
The shaft for the HK-4035 series motors measures 8mm in diameter, and is 94.7mm in long. The Stock HK-4035 motors have a 6mm output shaft end on them. The pinion end of this shaft is ground down to 5mm to allow the user to install 5mm pinion gears. The shaft kit will also fit other brushless motors that require a 5mm shaft of this length. The shafts can be cut shorter with a Dremel tool and a cut-off wheel if necessary to fit other motors.
This is the new version shaft made from a new, much stronger SKH51 Steel alloy that will hold up to the most extreme flying styles. The new HK-4035 motors manufactured after December 1, 2009 use these new shafts in them, so if you are looking to get the hardest and strongest shaft available, this is the one. This material is much more expensive than the earlier material used, and this is why these shafts are significantly more pricey.
Note: The shafts in the Scorpion motors are a slight press fit into the aluminum front housing. The shafts will not just slide out when the setscrews are removed. They need to be pressed out in a bearing press, or in a drill press, with the front housing of the motor supported in a block of wood to prevent warping the front housing.