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RV-12 Wing Plans addendum & hints

Mich48041

Well Known Member
RV-12 Wing Plans addendum & hints by Joe Gores
The following has NOT been approved by Van's.

Suggestion to make finding parts easier: Print the bag numbers on the plans next to the hardware part numbers.
Page 14-02 Step 7: Notice that two holes in both W-1212B Left & Right are countersunk on the outside surfaces.
Page 14-02 Step 8: It is ok if the bearing can be inserted with finger pressure without using tools.
Page 14-02 Step 9: Before assembling, make sure the W1212B L&R are flat or curved slightly inward at the bearing end.
Page 14-02 Step 10: After squeezing each rivet, make sure the bearing turns freely. Mine did not and I had to order new parts.
Page 14-03 Figure 2: Change "W-1207C ATTACH RIVETS" to " W-1207C ATTACH ANGLE" in two places.
Section 15: The rib part numbers can be very confusing. I suggest that each rib be numbered from 1 to 13 (or 1 to 14) and its corresponding position on the spar be numbered. You can also spray a spot of primer paint onto each rib using different colors for left and right wings. It will not take long to mark the ribs and doing so will prevent mistakes later.
Page 15-04 Step 6: Note that the W-1210-L is attached to the outboard side of the attach angle even though the RIB DOUBLER will be bent in the process. I called Van's and was told to do it like the plans even though it does not seem right to me.
Page 15-05 Figure 1 bottom left note: change "W-1208 MAIN RIBS" to "W-1208 NOSE RIBS"
Page 15-06 Step 4: Change W-1206-L to W-1206-R
Page 15-06 Figure 2: Do not overlook the use of LP4-4 rivets as mentioned in the note.
Page 15-07 NOTE at top of page: Temporarily put the flaperon counterweight pipe inside of the aft main rib lightening holes.
Page 15-07 Step 3: Change the word ANGLES to ANGLE. Notice that all of the nose ribs are attached to the inboard side of the spar attach angles except this one, W-1208-R attaches to the outboard side.
Page 15-07 Figure 1: Change W-1208 to W-1208-L (forward and aft trimmed, 4 places).
Page 16-02 Step 1: Final?Drill to 7/64 inch the #31 holes . . . Change "mount plates inboard" to "mount plate's inboard". (added apostrophe)
Page 16-02 Step 4: The vane pivot screw should only be tightened snugly, not tight enough to deform the plates. Choose washer spacers so that the vane is able to slide on the pivot bolt with a few thousandths clearance to make sure that it does not bind.
Page 16-02 Step 6: Change .125x2x2 1/4 to 0.125 x 2 x 2.25
Page 17-02 Figure 3: It would be nice if the plans had an exploded view of holes that need to be left open on the trailing edge.
Page 17-03 Step 2: Rivet the inbd, mid, & outbd wing skins to the skeleton ONLY as called out in Figure 1.
Page 17-03 Figure 1: Change "CS4-4 28 PLACES" to " CS4-4 29 PLACES".
Page 17-03 Step 3: Think ahead so that the rivets, that you are about to pull, do not interfere with pulling future rivets.
Page 17-04 Figure 4: Change "AN426AD3-3.5 2 PLACES/NUTPLATE" to read "AN426AD3-3.5 2 PLACES PER NUTPLATE".
Page 17-05 Step 1: My parts were mislabeled LEFT & RIGHT. Van's probably corrected this mistake on later kits.
Page 17-05 Step 2: Make sure to leave holes open where indicated. Drill hole in bottom of spar for riveting W-1204C.
Page 17-05 Figure 3: Caption should read, "ATTACHING THE WINGTIP TOP SKINS".
Page 17-05 Step 4: The tip of the Rear Spar Assembly MUST be trimmed to ease fitting between the flanges of the Aft Wingtip Rib.
Page 17-06 Step 1: Using a protractor, I took the time to make template-triangles out of poster board to facilitate bending the tabs to the correct angles. Then the W-1204D fit perfectly without fighting with it. I made Obtuse-Triangles using the Supplementary Angle of that called for in the plans. For instance, if the plans called for 30 degrees, I used the Supplementary Angle of 150 degrees (180 ? 30). You can see a picture of an obtuse triangle (labeled SCALENE) at http://en.wikipedia.org/wiki/Obtuse_triangle
Page 17-06 Step 4. The plans call for LP4-4 rivets but I think they should be LP4-3.
Page 18-02 Step 1: Change to 1 1/2 x 2 x 8
Page 18-02 Step 2: Drill and tap the 3/8 x 24 (NOT 16) hole first. The hard part is getting it concentric with the existing hole. There is no sense in making all of the cuts first and then having to buy a new part because you messed up the drilling and tapping. Do not ask me how I know. LOL When laying out the #30 hole, measure 9/16 from the center line on the back. BEFORE CUTTING the sides, skip ahead to Page 18-04 Step 6. Use a carpenter square to align the A-1206 Pivot Bracket and match drill the holes. To prevent elongating the spar holes, I found it easier to mark the holes with a sharpie, then center punch and drill the A-1206 in the drill press. Cut the sides last. The dimensions 2 x 1 21/32 are not critical. Do not spend lots of time trying to get it exact. Do NOT screw the bearings into the A-1206. If you get dirt into the bearings, you have to buy new ones at $12 each plus shipping. Leave the bearings in the paper bag until you are ready to mount the flaperons onto the wing.
Page 18-02 Step 3: Make sure you ONLY flute where indicated in the figures. You do not want flutes where holes will be drilled later.
Page 18-04 Step 2: File down the edge of the A-1208 to make it flush with the A-1210 BEFORE riveting.
Page 18-04 Step 5: The AN3 bolt is NOT included with the wing kit. If you do not have one, use a number 10 screw. The washers used as a spacer should add up to 1/2 inch.
Page 18-05 Step 1: These rivets are very hard to squeeze because of the close proximity of the perpendicular angle. I used a hammer and punch and bucking bar to drive these rivets.
Page 18-05 Step 4: Change "Step 2" to "Step 3".
Page 18-06 Step 1: Make sure the inboard skin overlaps the outboard skin on BOTH sides before riveting.
Page 18-06 Step 2: Rivet the trailing edge on both sides first. These are the hardest because the rivets on one side could interfere with the rivets on the other side. If you have to drill them out, it will be much easier to get the drilled rivets out before the rest of the skin is riveted in place.
Page 18-06 Step 5: Change "using the rivets called out in Figure 1" to "using LP4-3 rivets".
Page 18-06 Step 6: Save this step for later. Leave the rod end bearings in the bag so they do not get dirt in them, unless you want to buy new bearings.

I hope the above helps some of you. Others will disagree with some of my suggestion. Ok, I am ready. Please do not be too hard on me. LOL
 
All I can say is WOW!! I wish I had these hints during assembly!! Good, strike that, EXCELLENT, good job.

My suggestions:

Page 14-02 Step 10: Do not over squeeze these rivets. Either file the shop end of rivet or use a rivet shaver to get the shop end flush with the bracket surface. Otherwise the bearing will bind.

Page 16-02 Step 4: Ensure Hardware bag 2618 contains 16 AN-960-4 and 12 AN-960-4L washers. Looking at the 28 washers supplied to me they appear alike. All are 0.0225" to 0.024" thick. These are the small washers used to assemble the stall warning microswitch.

Specifications from Internet:
AN960-4 - #4 .125 x .312 x .032"
AN960-4L - #4 .125 x .312 x .016"

Elected to place 7 AN960-4 washers (I measured the one's sent to me at 0.023") between the outboard face of VA-195A and the micro-switch. This gave me a build-up of 0.161" compared to a buildup of 0.160" if the AN960-4 washers were per the MIL spec. I placed 3 of of the 0.023" AN960-4 washers between the micro-switch and the VA-195B keeper plate. With this arrangement the stall warning vane did not bind. After I installed the wing skin to check alignment, the vane was centered in the slot in the wing skin. (All of this was approved by Van's via a phone conversation.)

Page 16-02 Step 5: Van does not supply enough MS21042-08 nuts. I had two of the nuts, and need at least 1 more. Ordered the nut from Van's. Sent them to me and continued.

Section 17: Before closing the wings, consider an in-process inspection. Filled out the required form and my EAA technical counselor will mail one of the copies to the EAA, he will keep a copy and I have a copy for my build log. Good idea to have that second set of eyes look at your work.

Page 17-02 Step 3: Use a Uni-Bit to drill the 3/8" hole for the tie-down ring. You will get a nice round hole.

Page 17-03 Step 1: Used the following method to flip the wing. The instructions call for a third person to ensure the overhanging skins do not flop around and potentially crease at the most forward row of rivets. What I did was to use 3 pieces of 3/8" soft nylon rope and pulled the 3 over hanging skins in it a bit so they did not flop around as we flipped the wing over. Worked very well.

Page 17-05 Step 4: The "bottom" tip of the Rear Spar Assembly MUST be trimmed to ease fitting between the flanges of the Aft Wingtip Rib.

Page 18-02 Step 3: Make sure you ONLY flute where indicated in the figures. You do not want flutes where holes will be drilled later. Ditto, Ditto, Ditto. Don't ask me how I know!

Page 18-04 Step 5: The AN3 bolt is NOT included with the wing kit. If you do not have one, use a number 10 screw. The washers used as a spacer should add up to 1/2 inch. Place a nut on the end of the screw and squeeze the washers. This will help with the rivets that must be set on the bracket.

Page 18-05 Step 1: These rivets are very hard to squeeze because of the close proximity of the perpendicular angle. Used a hammer and punch and bucking bar to drive these rivets. Another alternative is to use what was on the suggested tool list. Alternative... used the 1/8" rivet x 1/2" thin/tall cupped squeezer and was able to set the rivets, even though they were quite close to the web of the bracket. Clamp the spar to the table, apply downward pressure on the manufactured head of the rivet and then squeeze it.

Page 18-06 Step 2: Rivet the trailing edge on both sides first. These are the hardest because the rivets on one side could interfere with the rivets on the other side. If you have to drill them out, it will be much easier to get the drilled rivets out before the rest of the skin is riveted in place. Add... Ensure a bit of downward pressure is applied with the pneumatic rivet gun as you rivet, this will ensure the shop end of the rivet stays flush with the flaperon skin. The upper skin rivets interfere with the lower skin rivets before they are both set.

JOE, PLEASE do the same with the fuselage kit as soon as you can. Or better yet, post as you go and edit the same post as you assemble the fuselage. You can edit your post as you accumulate ideas!!!

Again, a very GOOD list. Maybe Jim Cone can add his ideas. Wish I had it. Hope it helps others!!!!! ..marty
 
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In reference to this note, ?Page 18-04 Step 5: The AN3 bolt is NOT included with the wing kit. If you do not have one, use a number 10 screw. The washers used as a spacer should add up to 1/2 inch." How did you come up with a 1/2 inch? The bracket is slightly over 1/4 inch thick. THXs John
 
The Mil-Spec for the AN960-10 washer is as follows:

#10*(.203X.438X.063)*STEEL*FLAT/WASHER*ZINC

8 washers, per the Mil-Spec gives one a buildup of 0.504". Essentially 1/2".
 
very useful hints

Two thumbs up for these hints and tipps!!
I am currently in the process of building the wings and I really do appreciate everything you have written here.
Thank you!! :D
 
Joe
I think vans should have you approve the Plans before they print them.

Good Job

Joe D



RV-12 Wing Plans addendum & hints by Joe Gores
The following has NOT been approved by Van's.

I hope the above helps some of you. Others will disagree with some of my suggestion. Ok, I am ready. Please do not be too hard on me. LOL
 
Two thumbs up for these hints and tipps!!
I am currently in the process of building the wings and I really do appreciate everything you have written here.
Thank you!! :D

For those who have a tendency to rush for posting there requests before doing any research, this is an example of the power of the search tool and of the priceless help we can get on this Forum. These posts are 7 years old and still useful to builders!

Now go pay your dues for this year! :D
 
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A new post is Best

The search tool is a good thing However I think that old information is better than none but new information is best ( A lot has been learned in seven years ) also how would a new builder know what to search for if he don't know that there is a better way.

My View

Joe D




For those who have a tendency to rush for posting there requests before doing any research, this is an example of the power of the search tool and of the priceless help we can get on this Forum. These posts are 7 years old and still useful to builders!

Now go pay your dues for this year! :D
 
The search tool is a good thing However I think that old information is better than none but new information is best ( A lot has been learned in seven years ) also how would a new builder know what to search for if he don't know that there is a better way.

My View

Joe D
I agree and this is why the search tool lists the latest posts first. If there is no satisfying answer in the search then it's time to create a new thread. At the rate changes are coming from VANs one may wonder about the validity of early posts but there are parts of the RV-12 that have been very stable like the wings (did I hear Zenith?), all control surfaces and the engine. This is why I feel good when flying behind my Rotax, holding the 'manche ? balais' and sitting on my wings 😊
 
Rivet too short

Page 14-02 Step 7: To rivet the doubler W-1208B to stub spar W-1208C I used AN470AD4-5 instead of AN470AD4-4 as per plan. Both parts are 0.063 which results to a rivet length of 0.315. And that's pretty much 5/16".

I don't know why Van's wants us to use a -4 length rivet. I checked if clearance could be an issue later on, but to me it looks that nothing comes close to the shop heads when assembled to the wing ribs.

Maybe I have overlooked something, but I better feel going with a -5 since these parts are very structural.

2m79hy1.jpg
5nulty.jpg
 
Hi Rick
The gauge you are showing in the picture is used to determine the correct rivet length before the rivet driven.

That rivet is NOT yet driven. It only may look like. I chekced with the gauge, because it was so obvious that the -4 is too short.
Here's a close-up from above
35lyej6.jpg



An here is an image showing a -5 before squeezed.
302crq9.jpg


Any ideas?
 
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Interesting...It looks like the 5 is still coming up a little short. If there's room, try putting a cleco side grip clamp on either side of the hole. This might pull the two pieces together tighter than regular clecoes, and then the 5 might be the right length. If the 5 is very close to being the right length, you might squeeze one rivet as a test and see if the shop head is the proper size using the gauge Rick mentioned.

Here's another option: Do you have a rivet cutter? You can take a 6 and cut it slightly shorter, making it a 5.5 length. If you don't have a rivet cutter, you can accomplish the same thing by shortening the 6 rivet with a sander. Don't make it too long or it will bend and won't set right.
 
Wow, that is short

Thanks for the close-up pic. I'll have to check my plans notes but I'm guessing that I went with a -5 in that location.

As I learned doing my -7, not all of Van's rivet, screw & bolt call outs are 100% correct. They are correct most of the time. However, like in this case it's worth checking with a gauge if it doesn't look right - not just blindly following the plans.
 
As I learned doing my -7, not all of Van's rivet, screw & bolt call outs are 100% correct. They are correct most of the time. However, like in this case it's worth checking with a gauge if it doesn't look right - not just blindly following the plans.

Sometimes mistakes are made...... but sometimes rivets that people think are a mistake, were chosen on purpose..... Some times what would seem like a proper rivet length will be much higher risk at clinching over. This is much worse than a slightly smaller shop head. It is not as strong and should be removed. Then comes the risk of damaging the parts and having to start over.

I think you will find in this case, that the reason we are approaching 900 kit starts and no one has mentioned this before, is because the specified rivet size will produce a shop head that meets the Mil Spec

Quote from section 5 in construction manual......
Specification MIL-R-47196A for rivet installation allows for smaller shop heads.
The specification is available free online, is informative and worth reading. In many
instances, particularly in the newer kits, a shorter rivet will be called out than the
one that would meet the guide line above. The shorter rivet will still meet the MIL Spec.
requirement. This is done to avoid using a rivet size that may be slightly long
and more difficult to properly install.
NOTE: There are times when the correct rivet length is
not available. Depending on the application a shorter
rivet can be used or a longer rivet cut to the proper
length. Using a longer rivet, as is, can result in the
shank being bent over like a nail. We have chosen
to use a rivet that may seem too short in some places,
but will do the job adequately.
 
Installing stall warning access hatch

Page 17-04 Step 5: I found it easier and more comfortable to dimple the screw holes and to install the nutplates for the access hatch on W-1202-L mid wing skin prior to step 5 on page 17-02 where that skin gets riveted to the left wing structure.

1e6ln9.jpg
 
Joe,

I agree! It's in shear, so it's the diameter of the shank that's critical as long as the shop head is sufficient to lock it in place.

Rich
 
BUMPING THIS THREAD! Please find and bump Joe Gore's other similar threads on tips/mistakes/gotchas by plans section! They should be stickys - were tremendously useful to me during my build. But I think people don't see them much anymore. See the first entry in this thread.
 
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