A lot of the tightening problems people seem to be experiencing is actually caused by grub nuts, and poorly manufactured grub nuts. It's a bad design when it's made well! If your grub nuts do not all drop cleanly on the motor shaft to the same level, you have defective ones, ones not milled out all the way. And the collet can gall and not compress correctly on the grub nut. If you can apply a dab of oil to the arms of the grub nut before applying the collet and NOT getting any on the shaft, it works better. And if your grub nuts are not going on the shafts cleanly, you can ream them out carefully. If your outrunner motors have mounting screws on top, SERIOUSLY consider finding prop adapters so you can throw the grub nuts in the trash can where they belong.
I'm a Newbee and trying to build a Tricopter. I have the Turnigy MultStar outrunner motors and the 10x4.5 props. They came with the prop mount and the cone to tighten the prop on with. The keep unscrewing before I get off the ground. How do I lock then on???
Do not use loctite on these props, they will melt! Ok, I had this problem too at the start, I was not just tightening them strong enough. Just tighten them a max, near the point of breaking the hubs and after hundreds of flights, they are still tight on mine! Again, don't use loctite on plastic!
A note about props , hubs and spacers. I believe most methods of prop attachment are good if they are done properly. I had an incident where the collet style hub came off the motor shaft and caused a crash. The cone nut is tightened and the force is presented onto the shaft with the wedge style collet and it works well, however, the hub prop shaft below the threaded section and above the wedge was a larger diameter and did not fit into the prop spacer. The force was taken between the cone nut and the larger diameter and not by the nut pulling the wedge up into the base flange -properly clamping the hub onto the shaft. This is a problem -what to cut? Perfectly center an enlarged hole in the spacer or lathe cut the hub prop shaft to the correct diameter. -both difficult.
Watch my Video with cheap unbalanced Props and Motors and Decide for yourself: http://m.youtube.com/watch?v=AHI-lWWhpN8
I recommend balancing them sooner or later but they will work.
Ps: don't mind my poor flying skills. :)