Spirit 100 Joiner?

[KG4RVI]

Has anyone ever replaced the stock wood/aluminum joiner with a metal rod?

[Ollie]

I did make a carbon fiber joiner for a flying buddy's Spirit that is stronger and lighter than the stock joiner. It consisted of 13 layers of uniweb carbon in epoxy on the bottom, a shearweb of lite ply and a top lamination of 26 layers of uniweb carbon in epoxy. The assembly was cured under clamping pressure in a simple four part mold. The side pieces of the mold were 1/8 aluminum bar stock from the hardware store. The top and bottom pieces of the mold were stock Spirit wing joiners whose edge was covered by a strip of 0.014 mylar. The parts of the mold were waxed with paste floor wax. One of the stock joiners was clamped between the aluminum cheek pieces to form a trough. Thirteen epoxied strips of uniweb carbon were laid in the bottom of the trough one at a time and the ply shear peace placed on top. Then 26 pieces of epoxied uniweb carbon were laid on the ply shear piece. The second stock joiner, with mylar edge, was then placed on top of the assembly in the trough and clamping pressure was applied to all sides of the mold with screw clamps. After the epoxy set up to the green stage, the mold and clamps with the work inside were put in the kitchen oven at 125 degrees to finish curing. After the new joiner is removed from the mold all you have to do is trim the ends smooth and the joiner is ready to use. The whole project took me about an hour and a half not counting the epoxy curing time. If you want more details on dimensioning the ply shear piece, methods of work and pitfalls to avoid just let me know.

[KG4RVI]

I really didn't care for the stock joiner, it just didn't fit right. I ended up using some 3/8" OD aluminum tubing drilled out to accept a 5/16" steel rod. I elevated the wing to the 3.5 degrees shown on the plans and installed the aluminum tube level. I then installed a shear web to take up the rest of the space, glued one side of the joiner box on and filled the rest of the extra space up with epoxy. Since I am using a round rod, I installed an alignment pin near the trailing edge.

[alibodin]

I did not like the wing joiner as when I put the 2 halfs of the wing totgether there was a twist. Eventually I sanded and added wood and it is all fine. SHe flies very well off the slope.

A

[leverick]

I bent the stock wing joiner on my spirt 2 meter with a little to aggressive winch launch. I then replaced the center balsa wood section with a piece of hard wood (maple) sandwiched between the stock aluminum sections. I havent had a problem since.