Page 20-02 Figure 1: Get used to optical illusions in the RV-12 plans. Drawings should show objects in the distance as being smaller than closer objects. In these plans, both near and far objects are drawn the same size. That causes optical illusions. In the drawing in figure 1, the left side is closer to you and you are looking up at the part from the bottom. It might help if you cover up the left side of the drawing and just look at the right side.
Page 20-03 step 2: When drilling through thick material, it is even more important to make sure the drill is perpendicular to the work. Otherwise the rivet head will not lay flat on the aluminum. One way to drill perpendicular is to have a helper watch the drill in one axis while you watch the other axis. If you do not have a helper, drill a hole in a scrap piece of wood using a drill press to assure the hole is perpendicular to the surface. Then clamp the wood to the work and drill through the hole in the wood. A third method is to watch the reflection of the drill bit in the work and make sure the reflection is in line with the drill bit. However you do it, just drill a few holes and test them with rivets before drilling the rest of the holes.
Page 20-04 Figure 2: The center section aft bulkhead is labeled wrong. Change F-1204 to F-1204D.
Page 21-02 Step 1: Do NOT dimple the tooling alignment hole.
Page 21-02 Step 4: Notice that the rivet factory heads go on the bulkhead so that the rivets will not interfere with the landing gear installation.
Page 21-02 Step 9 & 10: Do NOT dimple the two screw holes for K1000-08 nutplates in the top flange of F-1206A
Page 21-02 Step 14: Notice that the outside of both bearing brackets are countersunk. The shop heads will be flush. Before riveting the bearing bracket assembly, make sure there is enough room for the bearing. Van's suppliers have had a problem machining the bearing holes deep enough. If your parts are not machined deep enough, one fix is to coat the insides of the side plates with enough paint to make more space for the bearing.
Page 21-03 Step 4: Only 2 rivets are shown to avoid cluttering the drawing. Put in all 6 per rib.
Page 21-05 Steps 10 & 13 refer back to Step 5 when it is actually Step 6.
Page 21-06 Steps 3 & 5 refer to ribs that do not have seat belt attach lugs.
Page 21-06 Step 7: Cut a 20.5" length of hinge. Always cut hinges 1/2 inch longer unless you are sure that the hinge barrels and tabs are on the correct end. It is better to waste 1/2" than 20 inches. Not to worry, there is enough hinge.
Page 21-10: If 2 holes along the edge do not line up, check to make sure that F-1203C is right side up.
Page 21-14 Step 1: You might find it easier to lay the fuselage onto its side so that gravity does not pull the washers out.
Page 21-14 Step 7: The SB500-6 snap bushings are slightly too small for the 3/8" fuel line. Put the bushings into a vise and squeeze the tabs inward. File away part of the tabs that protrude inside of the bushing. After snapping the SB500-6 bushings into place, make sure the fuel line goes through now while you can still easily get at them.
Page 21-14 Step 8: There is no step 8 on the drawing but it needs to be added. Install the bulkhead fuel fitting into the F-1204D bulkhead as shown on page 28-06. It will take you 5 minutes to do it now while you can get at it. After the bottom skin is on, it will take you very much longer and cause you frustration.
Page 21-15 Step 1: Both left and right sides have notches. You are viewing the F-1275 corner skins from the inside (concave) side.
Page 21-18 Step 10: Leave both of the WD-1233 L&R steps off or else they will be in your way. You can install them at any time in the future, even after the whole RV-12 is completed. The bolts will be accessible from inside of the cockpit.
Page 21-20 Step 1: Tighten the nuts to the maximum allowed torque. You do not want these studs turning when you install a second nut later.
Page 22-02 Step 2: Machine countersink the nutplate rivet holes on the firewall side of F-1288.
Page 22-02 Step 5: File away flange of F-1217A-R where it interferes with gascolator fuel fitting through firewall.
Page 22-02 Step 6: Consider attaching F-1201L Bracket on Page 22-03 Figure 4 before riveting F-1217A-R.
Page 22-03 Step 2: Do NOT dimple all 4 of the F-1257 channels. Only do the 3 that support the rudder.
Page 22-03 Step 4: Do NOT rivet the two holes along the forward edge of the F-1201B Firewall Shelf that will be riveted to the oil tank braces on Page 29-05 Figure 1.
Page 22-04 Step 0: Final drill 7/32" the VA-188 two nutplate screw holes to accept #10 screws. Machine countersink the VA-188 for AN426 rivets.
Page 22-05 Step 1: Rivet the vertical flanges first before bottom rivets get in the way.
Page 23-01: Consider installing the fuel system in Section 28 before doing section 23. It will be a lot easier without the sides being in the way.
Page 23-02 Step 3: I used a 3/4" steel water-pipe coupling inside of the angle and squeezed it with a vise. It will be too hard to turn the vise handle if you use anything longer than a coupling. Check the angle with a square and there should be about 1/16 of inch gap at the vertex. The object of twisting is to have the top of the longeron flat and on the same plane for the entire length. You can read how others did this step here: http://www.vansairforce.com/communit...ight=longerons
Page 23-02 Step 4: Figure 1 shows the hammer away from the vise, but the longeron should be struck right next to the vise. When bending the aft end of the longeron, I calculated that the end needs to be bent inward slightly less than 7/16", 27/64" to be exact.
Page 23-03 Step 1: The rivet hole in the corner is not countersunk because the rivet head will not interfere with the roll bar. The plans are correct in case you question it.
Page 23-04 Step 3: Rivet the bottom two holes of F-1203G with LP4-3 rivets.
Page 23-06 Step 5: If you have an older set of plans, it calls for dimpling the side skin flush on the inboard side. Later revisions have changed this to the outboard side.
Page 23-08 Step 1: Cut the hinge 10.5" long. After studying each half, cut another 1/2" off to make it match the picture.
Page 24-02 Step 1: There is no top or bottom or left or right to the F-1231 B&C Roll bar Straps. Bend them in the same direction of their natural curve. Just make sure that the angles at the ends of the straps match the channels. It is the forward and aft edges that must be orientated correctly.
Page 24-02 Step 3: De-burr all holes.
Page 24-02 Step 4: Some builders had trouble with the width of the roll bar not matching the spacing of the roll bar bases. Make sure the ends are the correct distance apart as you rivet. Read what other said about this at http://www.vansairforce.com/communit...light=roll+bar
Page 24-03 Step 1: Leave the bolts in the F-1231D Roll Bar Bases loose until you slide the roll bar over the bases. You can final tighten the bolts with a swivel-head wrench such as the Proto 1270-14. See http://www.grainger.com/Grainger/items/1Q284
Page 24-03 Step 4: If you have trouble removing the roll bar, a 2x2 from a crate, inserted into the lightening hole, makes a good pry lever. Set another block of wood under it for a fulcrum.
Since I built the fuselage before the tail, I had to skip the rest of section 24 and all of section 25.
Page 26-02 Figure 7 is looking at the inside of the angle.