Posted by Joe on March 14, 2017
We’ve found the “Skyholic” folding propeller to be a very reliable unit, however we have the following recommendations for pre-paring your propeller for operation.
1. Be sure that the blade mounting screws slide freely in the mounting hole in the blades. If there is any binding between the screw and blade with the screw all the way through the blade hole, use a 5/64” diameter drill (.078”, or 1.984 mm), to open up the hole to the correct size for free running movement. The existing hole will act as a guide so fixturing is not required.
2. Install the blades into the hub and lightly tighten the blade mounting screws. There should be NO binding whatsoever between the blade root and the inside of the hub “fork”. If there is binding, move the blades through the range of the folding operation, and remove them from the hub. On the sides of the blade you will see shiny silver colored areas where the blade root was rub-bing on the inside of the hub fork. Using very fine sandpaper on a radiused block, gently sand the shiny areas until they are gone, be sure to blend the area of sanding into adjacent areas to distribute the load on the blades properly. Re-install the blades and again check for freedom of movement...repeat the process as necessary to acquire freedom of movement.
3. We’ve noted that the drilling operation of the hub sometimes results in small “burrs” on the inside of the hub “fork” at the hole locations which can result in friction that impedes free blade movement. Remove these burrs with a sharp X-acto knife, or very fine sandpaper on a narrow block. Avoid sanding areas adjacent to the burr as much as possible.
4. Lastly, we recommend a very small amount of non-permanent “Loctite” thread locking compound, or alternately a very small amount of thick or medium CA glue be applied to the portion of the screw that extends through the hub after blade installation. The technique we use is to apply a tiny amount of either compound, back the screw out perhaps a turn or two to allow a bit of the compound to work it’s way into the threads in the hub fork, then re-tighten the screws into place. NOTE: There is no need to tighten the screw very tightly, as this CAN cause the fork to be compressed, and contact the blade root impeding free motion. The screws need only to be LIGHTLY tightened into place. The retaining compound will keep the screws from backing out.
Following these steps will ensure safe and proper operation of your Skyholic folding propeller. If you find any form of defect that you feel may effect the safety function of your propeller please contact us for return shipment and possible replacement procedure.
DJ Aerotech will not be responsible for this product if the steps above are not followed. Always follow the basic safety guidelines for operating powered model aircraft provided by the AMA.