Building a Javron Wing Kit

[Steve Pierce]

Very informative. I just put new spars and some ribs in a Dakota wing. I found that Snap-On screwdrivers are a must, and that for rib to spar type B screws best to run a #4 in each hole with small visegrips before assembly.

What would be neat is a tool to make pre-threading possible with rib in place - those ribs where I forgot to pre-thread were bearish. My hand still hurts.

Oh, and last time I put new spars in a wing, I had this neat electric screwdriver - seemed to make things easier. They apparently don't make the skinny kind any more, so batteries are non existent.

12" #1 Phillips and Dakota Cub spar screws work great.

 

[Bill Rusk]

Lift Strut Fittings

Next we will attach the lift strut fittings. These will also include pulleys and a aileron hinge point.



We will start with these packets



Note the closer hole edge distance of the spacer where the arrow is. This end goes towards the top of the spar.



You need to put in just these bolts for now. The other holes will have other pulley brackets or N strut fittings. This is the aft side of the front spar.



Front side of front spar





You need these packets now



Shows pulley bracket on aft side front spar with spacer.






Aft side of rear spar. Again just these bolts for now.



The aileron hangar will hit the top of the lift strut right where the arrow is. So.......



Put the pieces together and mark a line where they hit.



Then we are going to make a little bend/dent in the lift strut.



Looks like this. This will keep the bottom of the aileron hangar from hitting the lift strut which would prevent perfect alignment of the hangar.




This shows the hangar and the lift strut fitting and the arrow is where we put the bend in to fix the interference.

 

[Bill Rusk]

Aileron Pulley on aft spar at lift strut





Going to need these packets to install the pulley and bracket that attaches at the aft lift strut fitting on the rear of the aft spar



Assemble the pulley like this. There are no washers between the pulley and the bracket. Bolt, bracket, pulley, bracket, washer, nut, cotter pin in order.



Front side of aft spar. Note where the fender washer goes and the bracket.



Aft side of rear spar. Note that it takes two washers on each bolt.



So here is where we are right now. Aft spar lift strut, with aileron pulley mounted.

 

[Bill Rusk]

Compression Struts



The first compression strut (next to rib #1) will hit the wing attach fitting on the front spar. We will be using the upper hole, so we will need to grind a little off.
The lift struts are all numbered and they are mirrored for the left and right wings. The difference will only be the direction the rivets that are on the lift trust face. You can choose if you want. I like to put the rivet head facing the root. Just looks nicer.



We will sand it off along the line.



Shows the angle. It is a little low in the photo just to show what we are trying to do.



You will need these packets for the front spar lift struts



We will make the bracket vertical and drill #40 and insert a Type B screw. Also note the safety tab that will be bent up around the bolt. There is a packet of safety tabs.



Note the large washer that goes between the spar and the compression tube




Aft spar #1 compression tube packets needed



Note the wire pull goes between the aft spar and the compression tube. This is where we notched that rib.....remember? And why we notched that rib.



Aft side of the aft spar. We need the safety tab. No washer.



Front side of the front spar. Shows the bent safety tab and the screw on the bottom.




This compression tube needs to be leveled so the top is parallel to the top of the spars. Then the wire pull on the aft spar needs to be leveled against this.



Wire pull between the compression tube and the rear spar. Leveled with the top of the compression tube so it will line up with the tube going through the tank.

 

[Bill Rusk]

Compression Struts #2, 3, 4 (N strut), and 5


Compression struts 2 and 3 are pretty much the same except 3 gets double wire pulls on both ends



You will need these packets to install the compression struts #2 and #3




Front side of front spar. Note once again the Type B screw. You should know how to do this now
Note the safety tab too. No washer under safety tabs.




Note double wire pull on aft side of front spar. Level things again.




Front side of aft spar. Single wire pull on #2 Comp strut




Aft side of the aft spar. Safety tab properly bent.

#3 strut is pretty much just like #2 except both wire pulls are doubles. #5 compression is like 2 and 3 except it has single wire pulls on both ends of the comp strut. The short side of the wire pull always goes under the comp strut. The long side goes to the wire on all wire pulls.

 

[Bill Rusk]

Compression Strut #4 (N strut)



You need these packets



Note the wire pulls have slightly different bends. The shallow angle goes toward the wing tip. The sharper angle side goes towards the wing root. Once you get them in you can see the angles and the reason for the different bends.



Note the spacers. 2 of them (two wings) have a flat spot on the side. The flat side goes in the aft spar strut attach fitting with the flat side up against the bottom of the aft spar.
The round ones go in the front spar strut attach fitting.



Where the spacer goes aft spar fitting





All the compression tube bolts have a safety tab under them. No washer, just the tab.






The struts have a bushing in there so you don't collapse the tube when you tighten things up.



Note the orientations of the rivet heads and the bolts. We want to make sure nothing hangs down on the bottom and pokes out through the fabric.

 

[Bill Rusk]

Next we will attach the ribs. The front side of the front spar is pre drilled and the backside of the aft spar is predrilled. It does help to have a electric drill and a screwdriver bit to put these screws in. Type B screws.

After the ribs are attached with the predrilled holes, then we get to drill the holes on the inside of the spars (#40 bit remember) Put a .020 piece of aluminum between the spar cap and the web so you don't drill into the web. Then put in the Type B screws so all the ribs are all screwed in.

 

[Bill Rusk]

Drag anti drag wires/tubes



You will need this packet



This is the drag tube that goes through the tank. Shows the bolt set up. The nut always goes up against the spar



Same



In each bay alternate which wire is on top where they cross over each other. Each of these bolts needs two washers

 

[Steve Pierce]

Almost exactly like a PA18 wings so far. What is the gross weight of these wings and fuselage?

 

[Bill Rusk]

They are very close to stock except for a large box at the rear spar wing strut attach area like this.........



As you know the weak point for the wings is the rear spar where the strut attaches. Javron builds this box which reinforces this area. My understanding is the wing has been engineered and tested to 2200 pounds. Personally I set my gross at 2300 and I am comfortable with that.

Don't have weights yet but I will.

Bill

 

[Bearhawk Builder]

Just like Dakota wing kit too, yours might be packaged and labeled somewhat better.

 

[Steve Pierce]

They are very close to stock except for a large box at the rear spar wing strut attach area like this.........


View attachment 44936
As you know the weak point for the wings is the rear spar where the strut attaches. Javron builds this box which reinforces this area. My understanding is the wing has been engineered and tested to 2200 pounds. Personally I set my gross at 2300 and I am comfortable with that.

Don't have weights yet but I will.

Bill

I always find it interesting to see the structures on experimentals and their gross weight vs certified. Smith Cub was the first I had experience with, then saw Legend's wing go up to Dakota Cub and get tested in the Whiffletree to the same standards as the Dakota Cub wings. Interesting that this wing has a gross weight of 2200 lbs with the addition of the sheet metal false spar but a certified Cub requires the rear spar cap and rear strut attach fitting doubler to meet 2000 lbs.

 

[DENNY]

On 3rd glass of wine so need to throw gas on the fire, my 13 rib 1951 18A was good to 2070 lbs with none of the pretty boy stuff. Just change the VE speeds. Mike can post pictures of a cub wing held together with a high lift jack and ratchet straps that flew home. Bottom line is even a stock wing is great, any strengthening will help, given the right load/stress any can fail. I am not a big fan of drilling into the cab of a spar but I do like strengthening the strut support (could be longer).
DENNY

 

[skywagon8a]

..... but I do like strengthening the strut support (could be longer).
DENNY

The only part of that strut fitting which has been beefed up is the bearing strength of the hole where the strut attaches. The rest of that fitting hasn't been improved because none of the fasteners go through the fitting further up on the spar. For true added strength to be there, that black piece should be extended to pick up those two upper volts.

 

[Bill Rusk]

Wing Trammeling


The first bay is pretty much fixed by the drag tube that goes through the gas tank. It is bolted in and there is no adjustment.
We will then work each bay starting from the tank bay. There are basically 3 bays that we will true/trammel.



Clamp a string on the top of the ribs that sits right over the seam between the nose rib and the main body of the rib.




The string will start in the tank bay which is fixed and go to the last full rib (#15)




If you tighten this wire it will move the seam (rib) in the direction of the arrow.




If you are working with saw horses this might be a little more difficult but.......the tension on the wire should be.....if you pull up on the wire 8 pounds the wire moves 1/4". 1/4" in the center of the wire at 8 pounds pull. So a fish scale will be close enough. Here we use a sliding square and a fish scale. It is not rocket science, and it is not all that hard. The seam in the ribs is really handy in this case. It gives an easy and accurate way to trammel the wing. Do one bay at a time moving out from the tank bay to the tip. You have 3 bays to do.

 

[Bill Rusk]

#3 Compression Strut Pulley











You need these packets. We are going to add a pulley to the #3 compression strut.




It goes on the #3 comp strut just aft of the front spar. You can see the hole that is predrilled where it goes. This is the bracket. The pulley will come out to run the cable through then go back in. So you can put the pulley in now just to keep up with it and the bolts/hardware but don't cotter pin it yet.

 

[Bill Rusk]

Fuel Tank Straps


Time to install the tank straps. If you are running 18 gallon tanks you will have 2 straps, 24 gallon tanks have 3 straps. The order for 18 gallon tanks (from wing root) is top, bottom, bottom, top. The order for 24 gallon tanks is top, bottom, bottom, top, bottom, top.





You will need this packet





The straps all have a large washer on the bolt head. Needs to go in this direction to keep from interfering with the tank.




Front side of front spar. Double washer on all these bolts.



Aft spar. There are two holes back here. You don't need to drill one out. Use the right one. The larger hole goes to a flap hangar we have not put in yet.



Front side of front spar showing the top strap hold down attachment part




Back side of front spar.

 

[Bill Rusk]

Leading Edge


Next we are going to put the leading edge on. Easiest if you put the wing with the spar at the edge of the table or off the saw horses. You may want to clamp it a little to make sure it does not fall off or slip.
Now we want to block it for the washout. Javron does it a little different but for the homebuilder we will get to the same place in a different way. Make sure the tops of your sawhorses are parallel. It is not critical that the tops be level to each other i.e. you could have a little slope on the shop floor but the tops need to be parallel. Also the tops of the sawhorse need to be about 33" with the spars centered on the horse. The ribs are not level on the bottom so you need to compensate by only having the top of the sawhorse barely going from spar to spar. Basically at this point we want to bottom of the wing to have no twist. At rib 15 we need to raise the rear spar 1 1/8th ". (1inch and 90 thousandths to be exact but now we are splitting hairs and it does not matter). There will still be some flex in the wing to make adjustments but when you put the LE on the wing it does get more rigid. If you don't build in any washout before you sheet the LE it will be really twisted hard to get the washout in. If you don't want the full Piper spec washout in, (some folks like a little less) now is the time to set in what you want.
We will use cargo straps to pull the leading edge up tight. I know there are homemade clamps out there, like the ones Steve Pierce uses, and they are great, but I am trying to keep this simple for the average Joe. You can buy cargo straps at Home Depot and when you are done you will be able to use them for other things. I know they are a pain to figure out how to use, then after you get them all figured out you don't use one for a while, so you have to relearn it every time you use one. Or at least I do. Get comfortable with them now. Lay them out so they are ready.




First thing we need to do is mark a line with a permanent marker in the center of the rib. This will allow us to make sure we are putting the screws in the center of the rib. Make a little jig with a piece of scrap aluminum like this.




Line in the center of the rib



We will start from the tank bay. It is better to put your tank bay lid nut plates in first. There are 5 to a lid so spacing is 3/4 from edge then 7/78 from the same edge. 15 1/4 from that same edge. Then go from the other side and come in 7 7/8 then the last one is 3/4 from that edge. This will give even spacing. If you are doing a 24 gallon wing it will be 3/4 for first one, 10 5/16, 20 5/8, other side 10 5/16 and 3/4.



Hook the straps over the rear spar like this



Get the straps laid out nice and smooth and flat.




When you wrap the straps make sure they are on top of the nose ribs. One strap per rib for the panel you are installing. If you tighten them down and they are not on the rib you will dent your leading edge. You don't have to tighten them down too much. You can still roll the LE piece around to get the back lips even up against the spar cap. The LE pieces are predrilled. You can slide the strap a little off to the side of what ever rib you are working on, but again don't pull it very tight when it is not on a rib. You can look through the holes and adjust the rib so you are drilling into that center line on the rib that you drew. You can see the line through the hole. It helps to have a 4' long stick (like 1/4 molding with a nail in the end sticking out. You can push with the end of the stick or hook the nail over the rib to pull the rib. Another option to adjust the nose rib....if you gently push/pull on the center of the main body of the rib that will move the nose rib. We are using a #46 drill and the Type A screws. So tank bay first, then work out to the tip. 4 skins total.

The square tip wing is a little different sequence because of the way the LE skins are predrilled. Put the #2 LE skin on first (that is the one next to the tank bay) then the tank bay skin. When doing this do not install the screws on the outside ribs. You will see this because those holes are not predrilled. They will get drilled using the overlapping piece that is predrilled. Then #3 skin then skin #5 (the round tip wing does not have 5 skins it only has 4) then #4. This will put the predrilled skin over the top of the undrilled skin so you will know where to drill. So you are saying....if I cover the holes how do I know it is centered over the rib? The only one not predrilled will be the edge rib and you can center the rib flush with the previously installed skin so that will take care of that. It will make sense when you lay it all out.





The small rib bays will get two screws. Type B so drill with a #40. The larger bays will get 3 screws, one in the middle as well. Both top and bottom of the spar.





It helps to clamp a bar (angle aluminum, steel or whatever) across the bay you are doing to ensure the skin is level across the bay.




The end ribs, #1 and #15 need to have the screws replaced with Counter sunk rivets. The will both have overlay parts (wing root fairing and tip cover) so they need too be flat surfaces. Several ways to do this. Pull rivets will work here. A note on pull rivets. They are not as good as a bucked or squeezed rivet. They are especially vulnerable in high vibration areas/applications. Prop wash area is an example. They will "work" and become loose to the point that they really aren't doing much good. As much as possible try to use squeezed or bucked rivets.



Ok.......we are really making progress. We have a big chunk done. Next we will start to work on all the stuff attached to the aft end of the wing. Time for a break. Pat yourself on the back and have a beer. Ya done good cowboy.

 

[Bill Rusk]

Trailing Edge Stuff



We need to put a spring on the flap bellcrank like this. So drill a hole in the tank strap to the left of the flap bellcrank.




Larger photo so you can see what I'm talking about. This is only for the 18 gallon round tip wing.



If you have a square wing or 24 gallon wing you will measure from the center of this hole 13 7/8 toward the wingtip, from the top of the spar go down 1 3/8" and drill for an AN3-4A bolt.




There you will bolt on a little tab to hook the spring to. The reason for this is the tank straps are not in the same place on the other wings.




We connect the spring to the bell crank like this. two washers go UNDER the spring.



We will be using this hardware to attach all the hangars, both flap and aileron




More hardware to be used




Hangar. There are different types





Different hangers.




Backside of hangar





Backside of hangar at the strut attach fitting





Install tail ribs 9A and 11A using the predrilled holes and Tube B screws.




Also need to install the bellcrank stop shown under the arrow here.

 

[Bill Rusk]

False Spar/ TE Install



Don't tighten the bolts to the hangars just yet. If you did so loosen them up a bit.




First draw a line in the center of all the TE ribs so we can align the ribs and make sure we are putting the screws in the center




It is easier and better if you put your tank nut plates in the tank bay TE part now. Same spacing as the LE piece





Lay out your TE parts




The edge of the TE ribs have a slight curve to them. We are going to file/sand that curve straight on Rib #7




See how it is straight here?







We want it to match the TE sheet metal panel#3




There is a little piece of metal that goes in the end of the #2 TE panel that closes the gap between the flap cove and aileron cove since they are a different shape. This is why we straightened out rib #7. To make it all line up.




Looks like this from the top inside. It is just screwed in. I guess you could rivet it in if you wanted to.





On a square tip wing you will have a small TE rib #8A and this rib will close the gap so this is unnecessary on the square tip wing.




This part goes on first. Like the LE it has to do with where the predrilled holes are.





On rib #15 we need to insert this little piece which again closes the gap. This will be rib 17 on the square tip. This rib is only used for alignment at this time. Don't rivet it in. We will rivet it in when we are done with the tip bow install.




After you put it in the slot Butt the TE panel up against it to close the gap, then just insert 1 screw. Next make sure it is square , this one is not as you can see from the arrow. So square it up before you put the other screws in.

Don't forget to put the screws into the backside lip of the tank bay and the box sections. And don't forget since we are going into the spar cap it needs to be Type B with a #40 drill. All the other sheet metal stuff we have been doing i.e. screwing the TE to the ribs is Type A screws and a #46 drill bit.



So the TE order is to put TE panel #2 first. Then do the tank bay (#1). Then do #3 panel then #5 and finally #4 which is the box part with all the holes. Again this has to do with how the pre drilled holes are in the panel.


After all is done we will put a flap on, make sure it all lines up and moves freely then tighten up the flap hangers. Same with the aileron hangers.




We will use this hardware pack to attach all the hangers to the TE cove. Use a #28 drill here.




We need to put a little 1/8" spacer under each hanger while we are adjusting and tightening and putting the screws in. After the hangers all screwed in and tightened you will remove the spacers. This will ensure they all have clearance around the sheet metal. You will need a max of 4 spacers as the square tip wing aileron has 4 hangers. The round tip wing will only need three spacers. Flaps will need 2 or 3 depending. If you have been careful with alignment the hangers will be evenly spaced from the cove opening all the way around. With everything cad cut and predrilled this stuff should all come out perfect.



Man we are really cooking with Crisco!! We only have two sections left. The tank bay needs a little work and we have to install the tip bow. We are getting close.

 

[Bill Rusk]

Tank Bay Stuff




We need to replace these screws with flush rivets. There will be a sheet metal wing fairing over the top so we need it to lay flat. There are 3 on the bottom too. So rib #1 TE has 6 screws we need to replace with flush rivets. Use a dimple die here. Metal is not thick enough to use a counter sink.





There are 4 screws on rib 15 TE that also need to be replaced with flush rivets for the same reason. An overlay is coming.




First we have to put a temporary brace on the #1 rib to make sure it is straight and does not have any bow on it.



We are going to be using these packets now. These are braces to prevent the fabric from deforming the ribs. Fabric has a tremendous pull when shrunk and will deform/bend steel, let alone aluminum. It is a good idea to tie off the #1 and #4 ribs with safety wire when covering to help mitigate this, otherwise your tank bay will not fit after covering because the ribs will be bowed from the fabric. These braces are important!






The ribs are predrilled for these braces




Bend the tab over as necessary and drill out that end hole with a #28 drill and attach to the rib with a #6 screw and a nut.



Put the other end against the spar, drill with a #40 and use a Type B screw. Front spar and rear spar for the #1 rib.




These are the braces that go on rib #4 (predrilled for these) to the front spar. They have to angle down to clear the aileron cable.



These are the braces on #4 rib going to the aft spar.




Next we install the strips of aluminum that will hold the sides of the tank cover. Trim and make sure the flutes line up. Scribe/draw a line 1/2" in from the side so you can make sure it goes under the rib 1/2" and stays straight while you are flush riveting it in. Then do the same for the #4 rib.
Then we will install nut plates 7 1/2 inches from each end and the one in the center will be 9" from either end screw. Like this.......

 

[Bill Rusk]

Wing Tip Bow


Now we are on the last steps. Everything here applies to the wing tip.




You will need these packets.




We are going to drill a couple of holes here, 7 3/8 from the center of rib #15




And put in rib 15A with Type B screws



Rib #15 nose is pre drilled



This fitting goes in there. There is a right and a left. They look a lot alike. The small side goes to the top. Squeeze the rivets and boom. Task complete.




Put these parts on the front spar like this





And on the rear spar like this.

 

[Bill Rusk]

Now we have to sand and shape the end of the tip bow so it will fit in that LE cup. Patience young Skywalker. Patience. Sand, ....fit....sand....fit....sand some more...fit....




Clamp the bow in place and continue trimming, sanding and fitting until you are happy. Here is where it gets a little tricky. You have to drill the holes from the outside because of the angles. Just look carefully and drill slow. It will come out OK. Pay attention to your alignment. Then counter sink the hole for the screw so it sits flush. You can do it. Use a # 19 drill for the #8 screw. Number 8 screws go in the steel brackets. Number 6 screws use a #28 drill and they go in sheet metal/ ribs.




Counter sink picture.





What it looks like screwed in

 

[Bill Rusk]

Wing Tip Bracing





There are 5 braces that are the same size and one that is a little shorter. The short one goes at the TE. They are drilled in #40 Type B screw 1/2" in from the rib.
This is the rear spar




Front spar



Screwed in to the back of the tip bow with Type A screws



This shows the location of the shorter brace at the TE




Finally The tip is bent around the bow and trimmed and you can use little brads like this.........or.....



You could use a #4 3/8th flat head screw. Drill a pilot hole in the wood, then open up the metal with a slightly larger drill, then put a little counter sink in the metal. Then if it were me I would hit the screw head with a Dremel tool sander to smooth it out and make it perfect.




Remember this little rib insert box? Time to put it in. Four flush pull rivets will work fine. It just makes the fabric look nice.


Don't forget to tie up the drag anti drag wires where they cross each other.



Ok....pretty much the last thing on our do list. If you want you can add the LE tip cover. The easy way is to do it is to overlap the LE and use 4 Type A screws into the rib and a Type B screw into the tip bow. This creates several bumps in the fabric. I would (I will) probably rivet a 90 degree bracket to the side of the rib so I could make this flush. Its only purpose is to make the fabric flow smoother around the compound curve of the LE tip. Experimental is fun because you can do it any way you want. If you are using this guide to build a certified wing up ya gotta do it Pipers way.

This has been fun.....well not really.....building the wing is fun....doing this thread, not so much. I'm not a computer expert (or an expert at much of anything) so it is tough and stressful for me. Thanks to Steve Johnson for his computer expertise and patience.

Next ....in a few weeks..... we will do the flaps and ailerons.

Hope this helps

Bill

I have had the thread mostly locked for continuity, it is open for comments now. Please be kind. I am not an expert, just trying to help others as best I can.

 

[skywagon8a]

These two braces are used to minimize the pulling strength of the fabric bending the rib trailing edge, thus jamming the end of the tip bow into the outboard end of the aileron. Look at any fabric wing airplane with a tip bow. It is not unusual to see some distortion in the gap between the aileron and the adjacent rib. Sometimes to the point of having actual interference.

 

[Bill Rusk]

Thank you Pete. Per your input I immediately edited that into post 51 but it never hurts to repeat it. Even with the braces the fabric can bow the ribs. You are spot on.

Bill

 

[RVBottomly]

Drag anti drag wires/tubes


View attachment 44920
This is the drag tube that goes through the tank. Shows the bolt set up. The nut always goes up against the spar


View attachment 44921
Same

Drag tube through the tank. Is Javron the only one holding to the old setup? I'm probably going to do the same thing.

 

[mike mcs repair]

Drag tube through the tank. .

that's common.....

 

[Bill Rusk]

Building the Flaps and Ailerons

First and this is ..... IMPORTANT..... DO NOT BEND THE SPARS!!!!!

The spars come bundled together and taped up. The spars are drilled and notched. This notched area in the center of the spar is REALLY weak and it is SUPER easy to bend it. Be really careful not to leave it unsupported and bend it.



Here are a couple of photos of how you might want to build a table/work bench if you do not have one. It helps a lot to have a little overhang around the edge to make it easier to clamp stuff. IE don't put your support 2x4 right out to the edge of the top. You will need to make your table 2'x8'. The aileron will still hang over a little but this size will work just fine.




A couple more photos of a good bench




There are a lot of ways to build a bench, this is just one idea.



The first thing we will do is cut 4 2x4's that will go across the bench and hang over about 6 inches. By making them the width of your table you can clamp the back side on. You could make these shorter if you are willing to put screws or nails in your table. Some folks consider the table as a tool and want to preserve it. Others consider the table/bench as sacrificial and don't worry about messing it up a little. Your choice. You do not need the padding. This will make it much easier to rivet the ribs on. We will be building an aileron. The flap is pretty much the same. I will include notes on that as we go and have a couple of summary paragraphs to that effect as well.



In this photo you can see the holes in the spar and also where the sides are notched. This is where and why the spar is so fragile at this point. Once it is built up it will be fine....but once again.....BE CAREFUL.....DON'T BEND THE SPAR



This is where we are. We have a bench and we have 2x4 extensions with a spar in position. The spars are labeled and that writing needs to go towards you.



Next we will cleco the control horn in place. Remember the lettering on the spar needs to be towards you so it will all fit up and look like this.
If you are not sure where the metal plates fit just check the hole alignment. If the plate holes and spar holes are not perfectly lined up you have something wrong. This kit is all done in CAD and it all fits perfectly. If not you probably have something upside down, backwards, left on the right, right on the left, the wrong parts together etc. You will figure it out. Think of it as a bit of a puzzle. Label things as you go if you need to.




As before, you may have to touch up the holes a bit.

 

[Bill Rusk]

Then we will put a hinge bracket there. Make sure you use the right hinge bracket. The flap brackets are longer than the aileron brackets. Also, we will use these steel rivets. This is probably the hardest part of building the flaps, or ailerons, or wings. Don't panic. This is a small "problem to be solved". This might be a good time that you need to get a little help. Find a friend that has built a Vans RV-XX kit and feed him a little pizza and beer for an hours help. If you don't have a rivet gun, don't know how to use one, etc, don't hesitate to ask for help. We only have a few of these rivets to set (8 total) so it is not a huge deal. Don't panic......breathe......you can do this. There should be a few extra steel rivets to practice with. Find a little piece of scrap, drill a couple of holes, and drive a couple of practice rivets. The steel rivets are only on the ailerons. The flaps will use all aluminum rivets.








Included with your kit will be this special bucking bar that Jay makes up. It is pretty much a one time use item. When done you can keep it, or drop it off when you see him at Oshkosh.






It fits in like this. Lay the spar on top - DON'T BEND THE SPAR - make sure the rivet head is seated up against the hinge, you will have to lift the spar up slightly when you do this.



The rivets go in this way



But you will also need to make up this rivet tool. This is a 5.5 inch rivet set but we have ground down the end where the rivet head is to make it thinner so it will fit in the hinge. This is not hard to do. Put the other end of the rivet set in your drill, then while it rotates via the drill push it up against a belt sander or grinder to reduce the diameter until it will fit in the hinge space.



It will look like this. You can see that we needed to shrink the diameter of the set to make it fit up against the side of the hinge bracket. These are steel rivets so they take a little more time and force to set. Make sure the rivet head is seated and flush on the hinge surface, you will need to lift the whole assembly off the custom bucking bar so only the rivet end is against the bucking bar, then rivet away.



In this picture the right rivet looks good. The left rivet needs a little more bucking.

That is it. That is probably the hardest part. Javron considered doing this at the shop but it really messes up the packaging and shipping with this part riveted on. It no longer nests and just creates a big problem for shipping the kit.


We will use these rivet packs to attach the other hinge brackets. A little info on rivets. There are two types for our purposes. "soft" rivets have a tensile strength of about 16000psi. Other rivets are structural and usually have a strength of 38000psi. You can feel the difference when you squeeze them. All the rivets in the flaps and ailerons are soft (they have the "A" designation in the name, like above as AN470A-4-4) except the steel ones we just used.



Here we are squeezing the rivets for the hinge brackets.