I was initially concerned about the structural integrity of the fuselage, since the removable canopy part provides zero contribution to strength here. However, I'm happy to report that neither the nylon bolts nor the fuselage had any cracks or failures so far.
Hi Mike. I am fascinated by your post of the Electric SV-11 ARF wing take off method. You wrote that back in 9/10/2018 and you state then so far nothing broken.
Would you update your comment on the strength and integrity now on your Electric ARF SV-11?
I am so hoping that it worked because I would like to copy that.
Steve - Ready to go in Circles again!
Steve, the SV-11 is still alive and well, and the take-apart system has held up remarkably well, even after a couple of unrelated accidents that required mild repair elsewhere in the fuselage. Overall, I'm very happy about the decision to go with this take-apart system, as it has made my life so much easier in terms of storage, transportation, maintenance and repair.
If you are actually going to build this way, here a few details that didn't get captured in text (refer to pictures above):
- Before gluing the wing halves together, make inserts out of 1/2" hard balsa where the leading edge carbon rods will reside, and glue them into each half from the inside of the first rib bay using epoxy or thin CA. The inserts must make contact with both ribs and the sheeting. Stock leading edge alone does NOT have enough wood/strength to properly capture the rods! There must be at least 1" of wood in the area where pins will reside.
- Once the wing halves are flued together (don't forget to install the bellcrank pushrod first), the trailing edge area gets reinforced with 1/16" plywood plates, top and bottom, and the entire center section of the wing gets laminated with 2 - 3 oz/yd fiberglass cloth/tape about 2" wide, using thin epoxy.
- After that, the leading edge receives 1/8" carbon rods/pins (thin CA or epoxy), and the trailing edge gets drilled for 1/4-20 nylon bolts. Install flap horn, and the wing is ready.
- On the fuselage side: I used 1/4" aircraft plywood to hold the back of the wing, and simply drilled and tapped it for 1/4-20 thread. You could also use blind nuts. This 1/4" plywood plate gets glued into two 1/8" ply cradles which are laminated to the sides of the fuselage. All assembly is done using high quality epoxy (I recommend West Systems 105 resin with 205 hardener; a quart-size kit will last a long time and is WAY stronger than any hobby-grade epoxies out there, like Zap or Bob Smith). The leading edge pins get captured in a 1/8" aircraft ply plate installed from the inside of the battery compartment, again using epoxy. All assembly operations happen while monitoring incidence angles using Robart incidence meters or similar, and jigs to hold things in place (however primitive they may be).
- A comment on holding the canopy hatch using magnets. This system has worked for us for hundreds of flights, including on very windy days, without a problem. But as Murphy's Law has predicted, the only fly-away incident with the canopy happened during my son's official flight at Dayton last year, which cost him 1st place in Advanced. So, no more magnets for us, and we will be switching to spring-loaded canopy latches. We get those either at HobbyKing or GatorRC.
Good luck! If you have any questions, post them here or send me a PM.