Source: 2006 Q3 Beartracks
Following a suggestion from Bob Barrows, AviPro Aircraft now offers to scratch builders a new package of wing parts. The purpose of this package is to eliminate some steps in building your wings that many builders find difficult. Finding an eight foot brake you can use and then bending up your spar webs to match your ribs can be a lengthy trial and error process – hard to get right. If the spar web heights do not closely match the ribs, your wing skins will not look so good. After more than eighty sets of wings, our factory wing team does these bends very precisely.
This package includes the bent spar webs for the main spars, rear spars, false spars, aileron spars, & flap spars. Also included are the only other pieces that require bending on an eight foot brake. These are the aft wing skin stiffeners in the flap area (4 pieces) and the trailing edges for the aileron & flaps (4 pieces). This package includes all the ribs as they come from the factory that professionally hydrforms them. These are 48 nose ribs, 16 main ribs (.025), 8 main ribs (.032), 16 aileron nose ribs, 16 aileron ribs, 26 flap nose ribs, 18 flap ribs, 6 trailing edge ribs, 16 aileron pocket ribs, and the 4 false ribs. All ribs have their lightening holes cut and flanged. The ribs still need to be straightened (fluted), and have their vertical angle stiffeners riveted on. The price for this package is $2350 + shipping/handling/boxes.
The ribs are drop shipped from Oregon, and the spar webs are shipped from Texas. If interested, call or email Mark at N95MF@hotmail.com or 512/626-7886
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Flanging Rib Holes with Press Dies
Bob Barrows in the 1995 Beartracks showed his method for flanging lightening holes using a stick. This is another method Rob Gaddy is using for his ribs.
1. Fabricate 2 backer plates from MDF, same size and must fit inside flanges, big hole same size as the outside of the flange – note the recess to clear the flange on the hole previously done.
2. The squeeze is applied by ¾ inch threaded rod and nuts mounted in a vise. Use double thickness MDF for the base, backed with a steel plate. The base needs to be bigger than the hole in the backer plates.
3. The rib with backer plates centered on hole to be flanged is placed on the base. Plug shown up-side down, ready to be placed over threaded rod. The plug has a 45 degree chamfer that actually makes the flange.
4. Plug is forced down into the backer plate with the threaded rod. Note the steel plate to distribute the load on the MDF plug. The plug has a flange so that it will go down only the correct amount.
5. Here the flanged rib is removed from the base and ready for disassembly. Note the plug where the distance from under the plug flange to the 45 degree chamfer is the same thickness as the backer plates.
6. Success – This hole is flanged!