THE PROPER PRESERVATION OF PROPS

 

While we really love to sell props, we would prefer if they were for a new project rather than replacing props lost from existing models. With that being said, I will outline some of the steps you should take to make sure you keep the prop you have.

 

First, if your prop threads onto the shaft with a blind hole in the prop hub, make sure that the threaded portion of the shaft is the proper length to bottom out in the hub. This will help to lock the threads. You should also consider the use of loctite and a jam nut. The jam nut threads onto the shaft ahead of the prop. The prop is then threaded fully onto the shaft and the jam nut is then backed down the shaft to the prop hub. The nut should then be tightened against the prop hub. This will provide a lock nut effect. For props that have a through hole, make sure that the aft nut is either a lock nut or has a lock washer and again consider the use of loctite. One other thing to be aware of: Many of the commercial 1/8 prop shafts have a 6-32 thread. This is the wrong thread for this diameter shaft. To properly form a 6-32 thread the shaft needs to be larger than 1/8 (5-40 is the more appropriate thread for 1/8 stock).

 

Therefore, the 6-32 thread is not fully formed and the threads do not hold as well as they should when used in a properly threaded prop or nut. Always be wary of this and make sure everything is in place and properly tightened.

 

For those props that have a plain bore and set screw, make sure that the shaft is tight in the bore and that there is a flat on the shaft for the set screw to seat on. As an added safety measure, file the flat such that the aft end of the flat is deeper than the forward end. This way even if the setscrew loosens slightly, you will not lose your prop.