Piper J-4E Cub Coupe
I have spent an inordinate amount of effort coming up with the two removable wing struts for the J-4E Cub, which are shown below. The amount of time spent fabricating, trimming, sanding, and “tweeking” the struts went on forever. This is one of those tasks that is without end so at some point you just have to say enough is enough and stop!This picture shows a close up of the four strut ends with embedded magnets that attach to the bottom of the wing.This shows the right wing strut in place.This shows the left wing strut in place.
(without the two 1/16″ wooden dowel mechanical stops)The bottom end of the wing strut has a 3/4″ length of 1/32″ piano wire that slides into an 1/16″ aluminum tube epoxied in the fuselage as shown below. Notice that down loads on the wing will put the strut in compression. However, up loads will just cause the wire to slide outward in the aluminum tube.This is a view looking down into the left side of the fuselage. You can see the left wing strut 3/4″ long wire that slides into the 1/2″ long aluminum tube down in the bottom of the fuselage. A 1/4″ of the wire actually extends beyond the end of the tube, which provides for plenty of sliding length.This frontal view shows both removable wing struts in place.The total weight of the two finished wing struts as shown below is 6 grams (0.21 oz).This afternoon has been set aside to completely assemble the J-4E Cub’s model parts, electric drive train, LiPo battery, and radio equipment to get a final weight check before the covering starts………………………Tandy