3mm grooved shaft

where do you use it ?

Most of time front mounted motors shaft got damaged so we need another shafts but they needs to be grooved to set c clip in it.

right !, similar shafts are used all over, like in the heli , the main shaft as well as the tail rotor shaft , every crash generally distorts them bad , so like i fly the 450 heli , and need to store some shafts

This is how I groove them.