880kv jdrones & ddr store set slack and hex screw size

Hi! I have a bit of a loud noise when I start-up my hexa and upon examination looks like the outer barrel of the 880kv motor may have moved up creating a slack with the internal part of the motor.Not sure if I'm making sense but if you push down the outer rotating drum vertically, the clip at the bottom of the motor shaft separates from the base of the stationary part of the motor. SO with rotation, the motor tend to go up and the force with which this happen and then suddenly prevented by the clip at the bottom causes the sound. Tried remedying the situation by removing the set screw on the 880 that holds the shaft to the outer drum and tried pushing down the drum by "pounding" on the shaft. It didn't solve the problem though. Im afraid, one of these days, the force of rotation will overcome the clip at the bottom and not only will I hear the elevated sound but the entire external drum together with the propeller will fly off and cause a crash.

Also, what is the shaft-outer barrel of motor set screw hex size. I can loosen it but having difficulty tightening it as the hex I'm using somehow slip when tightening?

Any thoughts on the matter will be much appreciated.

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


  • i lost a motor just the other day - at high altitude and a long way away from me!  exactly the failure youre describing, where the circlip slips out of place and the rotor comes right off.

    as far as i can tell, the amount of slack along the shaft has little to do with it, as ultimately all the thrust comes to rest on that circlip.  i am fairly obsessive with the state of the motors and always check for play and adjust accordingly - standing the rotor on something with a hole for the axle to pass through and a couple of firm taps with a hammer will move the shaft down.

    i have no idea how common this failure is, but ive had one and dont mean to have another.  im currently building a new frame and the motors will be mounted upside down, with the shafts protruding out the back.  the down side to this is that all the thrust will now be seated on the smaller, 8mm bearing.  perhaps the bearings will wear out quicker but in theory this will rule out the possibility of a sudden failure without warning.

    as for the size of the allen key for the grub screw, i *think* its 1.5mm, but its certainly metric and was the smallest they had at the local hardware store.



This reply was deleted.