Repairs and riggings

With so many crashes and repairs needed to the Flying Flea/ Yellow Butterfly, I think I have become more adept with repairs and riggings.

 

I have had 2 broken propellers and a few other ailments:

• the 0.65mm nylon rigging line does not bend sharply when needed; I replaced with white sewing thread, although now I replaced the sewing thread with 0.33mm nylon fishing line to address the other issue of snapping;
• rigging lines pulled out of the attachment lugs; I replaced the broken attachment lugs or glued on a small washer; and
• the attachment lugs themselves pulled out from the wings; I glued the lugs and clamped them to the wings until the glue is cured; the pvc wing pivot broke; I replaced that with
• the wing pivot fabricated from PVC cover sheet sheared off; I used another plastic horn to be the wing pivot and superglued in placed. Similarly when the first plastic horn snapped, I employed the same except that I superglued it temporarily in placed and then epoxied the horn and struts;
• the rigging lines snapped; I tried joining with additional piece of thread, forming loops at the free ends and using that to attach the new thread and finally using 0.33mm nylon fishing line;
• the tension of the rigging lines collapsed the cabane struts; I had to re-rig the whole model, good thing too as the previous horn was displaced before the glue cured, leaving me with a lower forewing.

After so many re-riggings, I employed push rods for the wing because previously, when I was using 0.65mm nylon line or sewing thread as pull lines, I had issues with adjustability, and the rubber band to make the forewing pitch downwards places additional strain on the servo and linkages, the servo hummed.

 

Using push rods has additional benefits. Because the wing lugs are in board, it makes sense to install the pushrods first and then proceed with the rigging. Previously I had installed the primary roll rigging, then the secondary lateral rigging and then the incidence pull lines. It is difficult to install the inner pull lines as space was so limited and the lines restricted my fingers this way and that.

 

With the inner pushrods secured, they held the wing at the approximate incidence and I proceeded with the rigging. The first rigging is the roll rigging, and then the lateral rigging. All together, only six pieces of 3mm aluminium tubing, each approximately 3-4mm long are used. 2 for the 2 ends of the roll rigging line, 2 for the 2 ends of the lateral rigging line and 2 at the outboard pivot points where all four lines converged, so I can lock the roll and lateral lines inplaced in one go.

And if I shall have a chance to do up the main wing's actuating mechanism again, I shall fit the arm through a slot cut in the aluminium tubing because the arm now is worked loose and has slop. Good enough for pulling I guess, but not for pushing and would never be good enough if I put tail elevators.