The Wings – Page 2

I used maple for the wing wire blocks. I cut the maple to length and beveled the edges 45 degrees on the table saw. The tops are beveled 10 degrees to match the bevel of the spars. I marked the hole locations for the wing wire terminal brackets. Bowers was correct when he said that drilling these blocks was a tricky proposition. It would have been easier not to have the wing wire attach brackets predrilled. That way, I could have drilled them to match the block hole locations. As it is now, the block holes have to match the brackets, which is harder to do.

It took some head scratching and the help of several people to come to a solution for these holes. We started by using a nail set to dimple the hole marks. We then barely cupped the wood with a regular titanium pointed bit slightly smaller than the ¼” hole. We then moved up to the ¼” bit but only drilled about 1/8” into the wood. All this drilling was done with a hand drill. Then we built a jig on the drill press table out of heavy angle iron to keep the blocks straight and square. We drilled half way through the blocks with a ¼” 3 point brad tip bit, making sure to go slowly and clean the hole out frequently. We then flipped the block and drilled from the other side. We sometimes had a slight step in the center of the blocks due to marking inaccuracy and drill bit wander. We cleaned these steps with a ¼” straight fluted reamer. We will see later if these holes match the brackets or if I get to make new brackets for these holes.

Prior to drilling the spars, I made sure that the compression rib holes lined up on both front and rear spars. I then drilled the spars in pairs with the drill press as noted in the plans. (I have not, at this point, drilled the four holes for the aileron swing link bracket. In viewing pictures of some wings uncovered, I have noticed that the aileron push rod control system seems to be a “modified to fit” type exercise. With this being the case, I wanted to make sure of the location before I drilled these four holes. They can be added easily enough later.)

I then glued the wing wire blocks onto the spars one face at a time, back drilled and glued the other side and back drilled.

I began to slide the ribs onto the spars at this point. After insuring I had them in the right place, I glued on one side of the spar butt plates, back drilled and glued on the other side and back drilled. I slid the ribs to one side and began aligning the tabs on the compression struts for drag/antidrag wires.

I sealed the spar butt plates, areas under the compression ribs, and bolt holes with System Three Clear Coat.

Then I attached the 1/8” 1x19 stainless drag/antidrag wires to the outboard tabs of C2,3,&4 with zinc nicopress sleeves. (The 1x19 wire is extremely stiff. I found that a small amount of lubricant on the apex of the loop prior to pulling the wire taunt keeps the wire from splaying around the thimble. Also, this was really a three person job.) I then drilled holes in the ribs for the wires using the procedure called out in the plans. I also attached the AN130-16S turnbuckles to the inboard tabs of C1,2,&3. I used a thin washer behind the clevis pins on the turnbuckles.

I torqued all the compression rib bolts to the midpoint of torque ranges in AC43.13. Using the trammeling procedure described in the plans, I squared the spars with each other by adjusting each turnbuckle. I used heat shrink tubing (double layers) in areas where the wires cross and on the wire ends.

I now began to permanently attach ribs 3-10 to the spars using the method called out in the plans. It helped me here to use a string pulled tight across the top and bottom of the ribs from spar tip to spar butt to make sure I had them at the same level. I used ½” tri-stock cut to maximum length allowed between rib cap strips for corners. I held the tri-stock in place with ½” brass nails. To attach false ribs 3-9 I glued tri-stock to one side of the rib and let it dry. I glued the other piece of tri-stock to the reference line on the spar and let it dry. Then I attached the rib/tri-stock unit to the tri-stock on the spar. Make sure to check where the rib goes. Some tri-stock will have to be modified for hardware clearance.

Left wing thru step 12 was now sealed with 2 coats of Clear Coat (lightly sanded between coats) and hung on the wall to make room for work on the right wing.

Home The Wings – Page 4 The Elevators The Landing Gear

General The Wings - Page 5 The Fuselage - Page 1

The Wings - Page 1 The Rudder The Fuselage - Page 2

The Wings - Page 3 The Stabilizers The Fuselage - Page 3