BedeCorp supplies Matco brakes and master cylinders with the Bede BD-4C kit. There is one master cylinder attached to the back of each of the four rudder pedals. Each of the master cylinders behind the pilot’s pedals has an integral brake fluid reservoir. The cylinders behind the copilot’s pedals are “slaves” and do not have the reservoirs. Here is a diagram of how the plumbing gets hooked up, which will probably make it more clear than my words. (Click on the picture to see a larger version.)

Brake plumbing

I have been working on the brackets which will hold the bottoms of the four brake master cylinders. These brackets attach to the floor, between the rudder pedals and the firewall. Since there are several other structures already there, I had to create a dozen shims of various thicknesses and sizes to “even up” the floor so that each bracket will have a level surface on which to sit.

Once I got all of the shims made, I taped everything into position with “magic blue aviation tape.” You may have seen a similar product in the paint department of your local hardware store. The stuff that I bought looks suspiciously like the blue masking tape in your local hardware store but, since I am using it on an airplane, I am quite sure that it is aviation tape and not plain old blue masking tape.

Anyway, between the masking aviation tape and a little help from Candy’s hands, I got all of the parts (12 shims and eight brackets) to hold still long enough to drill the holes for the bolts. There are three bolt holes in each bracket so it took awhile to get it all drilled.

Here is a photo of the brackets in front of the copilot’s pedals. Robin Hood is sitting on top of the tube to which the copilot’s right pedal will be attached. If you click on the picture, you will get a larger version and it will be easier to see the brackets, attached to the floor at the bottom of the photo.

Brake master cylinder brackets in front of copilot's pedals

Once all of the drilling was done, I removed all of the brackets, shims, nose gear structure, and the black-painted pieces for the rudder pedals. There were aluminum shavings all over the place from all of the drilling. The only way to clean that up was to remove everything and use the vacuum cleaner.

Cutting Down the Steel Rudder Pedal Posts

First up was to shorten the T’s at the tops of the rudder pedal “posts” so that they would fit between the tabs on the backs of the actual pedals. I used a cut-off wheel and my 12″ disc sander to cut the steel, which made quite the shower of sparks and thoroughly “entertained” Candy, which is to say, she hid in the house ready to call the fire department in case I set the garage on fire.

When I got done cutting and sanding, the ends of the tubes were a mess. I had Candy take pictures of the clean-up process so you could see a couple of the tools that I have been using. (I have lots of pictures for you this week. Click on any of them to see larger versions.) First, the mess. I had drawn cut-lines on masking tape. When I peeled off the tape, the end of the tube was all jagged and the primer was wrecked from the heat generated by the cut-off wheel.

Messy end of steel tube

I started by deburring the inside of the tube. It only takes a couple of turns with this tool to debur aluminum. Steel was tougher, it took about a half dozen turns.

Deburring a steel tube

For the rest, I did the manly thing: I got out a power tool! I used a pneumatic die grinder with a small Scotch-Brite wheel.

Scotch-Brite wheel on die grinder

I ran the wheel around the outside edge and then flat across the top.

Smoothing the edge of cut steel tubing with a Scotch-Brite wheel on a die grinder

Deburring the end of the tube

The die grinder made quick work of the eight cut ends. Here is one, all cleaned up and ready to be repainted.

Cleaned up steel tube

Drilling the Hinge Holes in the Rudder Pedals

The rudder pedals have tabs on the back but, when I received them, there were no holes in the tabs for the hinge pins. I got to drill them which meant finding a drill press with at least 3.75″ of travel and some long drill bits.

I am a member of EAA Chapter 32 and, fortunately, the chapter has a couple of drill presses and one of them is plenty big enough for this job. I cannot imagine building a plane without the resources of my EAA chapter. No matter what problem stumps me, there are sure to be several people in the chapter who not only know the answer the are willing to teach me. It is a money-saving bonus that the chapter also has tools that I can use.

Here is a finished rudder pedal with the hinge pin in place.

Rudder pedal with hinge pin

The first challenge in drilling these was how to hold them still and perpendicular to the drill press table, since the pedals do not have any square edges. I hit upon the idea of clamping the pedal to an iron pipe, which worked beautifully.

Rudder pedal clamped to pipe

It was easy to hold the base of the pipe jig still on the drill press table. It looks like I am about to drill into my hand but I adjusted the press so that the bit could not reach down to my fingers.

Drilling a rudder pedal

I drilled each pedal in several stages, staring with a small drill bit, then a medium one, then a 5/16″ bit, and finished up with a 3/8″ reamer. The result was a pair of holes nicely aligned.

Finished rudder pedal

Alodine Again

Sunday was great weather so, for the first time since I got the Bede BD-4C kit, I spent the whole day working with the garage door wide open. I love spring!

I started the day by applying Alumiprep and Alodine to the brackets to which the rudder pedal posts will be attached. These will be visible on the floor so I want them to look good in gloss black and to be well protected from water that might get carried into the plane on people’s shoes.

I diluted the Alumiprep approximately 1:5, since all the metal is pretty clean. I diluted the Alodine approximately 1:3. At these concentrations, both processes took several minutes and were easy to control. It was a much better experience than last time, when I used both chemicals full strength. Here is the result.

Alodine drying on rudder pedals brackets

Once the Alodine dried, I spray painted everything black. No need for the paint booth this time; we had gentle breezes and warm weather so I just took the parts outside.

Rudder Cable Guides

The rudder is activated by a pair of cables that run the length of the airplane. The cables go through six sets of guides, four free-standing ones and two that are integrated into the walls of the main gear box. Back in January, I had fabricated the brackets for the guides. Today, I drilled the fuselage so that the guides could be attached. Everything is held together with clecos for now. I still need to remove stickers from various parts and clean off a lot of Sharpie marks before final assembly with bolts and lock nuts.

Here are the guides.

First rudder cable guide, between the bases of the control sticks, roughly even with the pilot's and copilot's knees.

Second rudder cable guide, on the center of the floor between the rear passengers' thighs. The steel push-pull rod for the horizontal stabilator will run through the U-shaped cut-out.

The third guide for the rudder cables is fastened to the brackets for a bell crank that “joins” two push-pull rods. The steel push-pull rod for the horizontal stabilator runs through the front of the fuselage. Just behind the back seat, it “turns into” an aluminum push-pull rod, which runs the last seven feet to the tail of the plane. This bell crank supports the joint between the two rods.

The third rudder cable guide is a couple of feet behind the rear seats

The fourth guide is about four feet from the tail of the plane. The rudder cables will run through one pair of holes. The horizontal stabilator trim cables will run through the other pair. The large diameter aluminum push-pull rod will run through the gap between the brackets.

Fourth cable guide, with holes for both rudder and trim cables.

Rudder Bell Crank

The last job of the day, which took a couple of hours, was to drill the holes in the brackets for the rudder pedal bell crank. The rudder cables terminate at this bell crank and a short push-pull rod runs out to the base of the rudder. The plans for the Bede BD-4C give the location of the holes in the top bracket. Everything else needed to be drilled to fit so the process was a matter of slowly fitting one part and then measuring where the holes for the next needed to go, drilling those holes, and repeating for the next part.

Rudder bell crank and brackets, looking aft

Rudder bell crank and brackets, looking forward

Congratulations. If you are still reading at this point, you certainly deserve a prize! Thank you for sticking with me.

Painted parts in mini-spray paint booth

All the painting would have gone a lot faster if I had been more organized and gotten everything together to be painted in one batch. As it was, I primed what I thought was everything and then had to go back and prime a couple more parts. Once primed, painting everything black went pretty quickly but still took two evenings because I had to wait for the paint to dry before flipping the parts over to get the second side.

Based on lots of advice, I opted for a high quality primer: SEM Self Etching Primer #39693. I chose Krylon Rust Tough Enamel in gloss black for the top coat, because it is a good brand and common to find in stores. When I need more, it will be easy to get exactly the same color again.

Once the parts were painted and the paint truly dry, I assembled the pulleys for the aileron cables.

Assembled aileron pulleys

Since I made the CS-12 brackets back on almost two months ago (see the last photo of the Brackets Brackets Brackets posting) it was very satisfying to finally use them for something.

The last task for today was to file down some end caps for the rudder pedals. You may remember, about three weeks ago, that I wrote about assembling the rudder pedals and posted this photo.

Testing the rudder pedals

In reality, those are just the posts to which the real rudder pedals attach. The tee at the top of the posts gets end caps in each end. Then a 3/8″ diameter bolt runs through tabs on the backs of the actual pedals and through the tees. This will allow the rudder pedals to rotate slightly and activate the brakes. (I will have better pictures of the whole thing soon, which will help this all make more sense.)

Here is a shot of the back of a rudder pedal with the bolt that will be the hinge pin.

Back of rudder pedal

I am waiting for some 6 inch long drill bits to arrive so that I can drill the holes in the tabs. Since the holes have to line up “perfectly,” I will drill them in one operation, through both tabs. It will not work to drill through one tab with a normal length drill bit, move to the other tab, and drill a second hole in the other direction.

When my friend Karsten made the end caps, he approximated the size since I did not yet have the steel tubes into which the caps would be inserted. Now that I have the tubes, I filed down the end caps to fit. Not having a lathe, my drill press had to do.

Filing down an end cap

I will admit, the painting was not as bad a chore as I feared it would be. But it’s sure nice to get back to building stuff instead of painting it.

I tested my mini-paint booth on the push-pull rods for the ailerons. (Click to see a larger version.)

Miniature paint booth

I have a few steel parts that are not yet primed. For these, I will start with an SEM brand self-etching primer. I am mostly concerned with corrosion protection so, if the parts will not be visible, primer is all they will get. For parts that will be in sight, like the attachment of the axles to the main gear legs or the posts for the rudder pedals, I will add a layer of gloss black rattle can enamel paint, like you see in the photo above.

I decided not to corrosion-proof the whole plane, since most of the metal is “alclad” aluminum, which means that it was manufactured with a thin layer of pure aluminum over the alloy. This thin layer of pure aluminum quickly oxidizes and protects the aluminum alloy (the strong part of the metal) from corrosion.

Despite this, there are some aluminum parts that I want to paint (for appearance) or to which I want to add an extra layer of corrosion protection (because they might get wet). I decided to use Alodine for these. Alodine is a chromate conversion process, which actually changes the surface of the part from aluminum to a harder, corrosion-resistant metal. It also has a cool gold color and forms a very nice base for paint without adding any weight or thickness.

To Alodine a part, you soak it in Alumiprep first, an acid bath which cleans the surface and eats away any existing corrosion. Second, you rinse that off and then soak the part in the Alodine. Finally, you rinse the Alodine off and let the part air dry. Once dry, the surface is hard but, until then, you need to avoid handling it so that you don’t accidentally wipe off the Alumiprep coating.

Here is my first batch of parts, hung up to dry.

Air drying parts treated with Alumiprep

I tried using the Alumiprep and Alodine full strength and shortening the time that the parts were in the baths but am not happy with the results. The processes ran so fast that I was unable to control them to my satisfaction. You can see it in the finished parts, which are pretty dark instead of having a nice gold hue. For future parts, I will dilute the solutions 3:1 with water.

During all that time, I did manage to manufacture a few more small parts. I made several more brackets and three push-pull rods, two for the ailerons and one for the rudder. (Click on any of the pictures to see larger versions.)

Rudder cable guides

These aileron push-pull tubes run vertically at the back of the cabin, translating the motions of the control sticks up to the torsion tubes at the wing roots.

Aileron push-pull tubes

Aileron push-pull tube rod end

Most of the rest of the plane is aluminum but these tubes are steel so I have primed them to prevent rust. Since they will not be visible, this is probably all the “decoration” they will get. Other steel parts will be in plain sight, like the rudder pedals and control sticks. Those parts will get nice coats of gloss black over the primer.

With the completion of the aileron push-pull tubes, I was almost ready to begin assembling the control systems for the flight surfaces (ailerons, rudder, and horizontal stabilator). Pretty much the only pieces missing were the rudder pedals and the control sticks. Since assembly needs to proceed from the front of the plane to the rear, I had to wait for at least one of those parts to arrive.

While waiting, I took all of the small pieces that I have been making and attached them to their right places on the fuselage with clamps. Here are pictures, from the front of the cabin to the tail.

Looking into the cabin from the right side, you can see the cross member where the rudder pedals will attach. Tapes to this cross-member are some of the brackets for holding the rudder pedals. Right behind that, the rudder pedals are sitting on the floor. Further back is the cross member to which the control sticks will attach. Clipped to this cross-member are some of the brackets for holding the sticks (orange and blue clamps) and a guide for the rudder cables (purple clamp).

Looking forward through the cabin, you can see the rudder pedals and the cross-members to which the rudder pedals and the control sticks will attach.

Turning and looking to the rear of the cabin, you can see the gear box, with the tops of the main landing gear legs inside. Taped to the front of the gear box are two brackets which will hold pieces of extruded angle that will run about 13″ forward to the cross-member for the control sticks. At the very back, you can see a guide for the push-pull tube for the horizontal stabilator, held in place with a light blue clamp.

Back half of the cabin floor

Looking aft from the cabin, you can see the guide for stabilator push-pull tube in the foreground and a larger contraption at the next cross-member. At that point, the small diameter steel push-pull tube ends and is connected to a larger diameter, lighter weight, aluminum push-pull tube which runs 7′ to the tail.

Looking aft from the cabin

This photo gives you a closer view of the transition between the two push-pull tubes and, farther back, a guide for the larger tube (yellow clamps). The holes on the sides of the guide are for the cables for the rudder and the horizontal stabilator trim tab.

Farther back in the fuselage

At the very back of the fuselage, almost hidden behind C-clamps, are a pair of brackets at which the rudder cables will end. The cables will attach to a steel see-saw like part that will translate the cables’ movement into a push-pull tube that will be attached to the base of the rudder.

Aft rudder cable brackets

Returning to the rear of the cabin, you can see how the base of the aileron push-pull tubes will be attached. The control sticks will work cables which will be attached to the bell-crank in this picture and there will be a second tube on the other side of the plane.

Base of aileron push-pull tubes

The BD-4C kit includes a 12″ long rod of .75″ diameter aluminum rod from which to machine a dozen rudder pedal end-caps. Fortunately, my friend Karsten made these for me. Sometimes a guy’s just gotta know a guy who’s got a lathe and knows how to use it! These end caps fit loosely into the rudder pedals and form a low tech “hinge.” Here you can see one of Karsten’s end caps bolted to one of my brackets.

Rudder pedal mounting bracket

This picture gives you a better view of how the end-caps and brackets and rudder pedals all go together. Each steel bar has two pedals: one has the two left pedals and the other has the two right pedals. The little tabs in the middle of the bars are the attach points for the cables and springs.

Rudder pedals with end-caps and brackets

We are almost there. With the end-caps fabricated and attached to the brackets (which I made back on January 8), I bolted the rudder pedals to the cross-member that will hold them in the plane.

Rudder pedals on cross-member

The whole assembly will get painted and then riveted to the floor at the front of the fuselage. But before any of that can happen, we had to test it. Candy was the first “pilot” to put her feet to the rudder pedals of our new plane.

Testing the rudder pedals

She even made appropriate airplane noises!

My first idea was to buy a metal cutting blade for my band saw. I found a supplier, paid a nutty amount of money for the blade, and never could get comfortable with the idea of actually using my woodworking band saw to cut steel. Being a woodworking saw, it runs the blade at 2,960 fpm but I have read that the blade should run at about 240 fpm for 4130 steel. I did find a write-up on the internet of a technique for cutting 4130 steel on such a saw but it involves pushing the material hard against the blade. Since the VS-16 spacer is only about four inches long and less than an inch wide, I could not think of a way to do that safely without getting my fingers uncomfortably near the blade.

In the end, I decided that the band saw was simply the wrong tool for the job. I bought a pneumatic cut-off tool with a 3″ disc and that made short work of the cutting. It was a little tricky using a cut-off wheel to make a long-ish slot in a sheet of steel. I kept getting the wheel just slightly sideways in the slot, which would jam the wheel and stop its rotation completely. I did get through it, though, and was much happier to have the sheet of steel clamped to my workbench and all ten of my fingers safely away from the business end of the cut-off tool.

My next worry was drilling the holes for the bolts and the rivets to hold the nut plates. I had read horror stories on the internet about people who “work hardened” 4130 steel trying to drill it. Once hardened, it becomes virtually impossible to drill and turns into a great device for dulling expensive drill bits.

The internet was my savior, once again, with words to be read and even videos on YouTube. I set my drill press for its slowest speed, put a couple drops of 3-in-1 oil on the spot to be drilled, and applied a fair amount of pressure to the bit. I do have pretty good TiN plated drill bits and they cut through the steel like butter. It was very satisfying to realize the the job was much easier than I had feared and that my inexperience had blown the whole thing way out of proportion.

When I had all six holes drilled, I used the Scotch-Brite wheel on buff the VS-16 up and make it look all purdy. Once I paint it, you won’t be able to tell, but it sure looks nice today.

Spacer made from 4130 steel

I have been working my way from the control sticks back to the tail of the plane, making the brackets to hold the control systems. With the VS-16 out of the way (it was a hold-over from when I made the rudder in December), I returned to making brackets and fabricated two brackets out of 2″x2″x.063″ aluminum angle and four brackets of of a flat sheet of .063″ aluminum.

CS-25 brackets made from 2"x2"x.063" aluminum

CS-26 and CS-27 brackets made from flat .063" aluminum

Next up: woodwork, believe it or not. There are hardwood spacers which go between the two CS-26 brackets and between the two CS-27 brackets.

After scrounging around my shop, trying several things, the piece which worked the best was a scrap of 2″x2″x.063″ extruded aluminum angle. (As usual, click any picture to see a larger version.)

A piece of .063" thick aluminum in the bending brake

The result is a couple of very nice 90 degree bends in the bases of the brackets.

CS-13 brackets made by bending .063" aluminum

By the way, I am trying a new way to include photos in my blog posts. Please let me know how you like the  way the photos appear in this posting compared to the way they appear in older postings.

Before I could install the floor, I had to remove several things from the plane which were in the way. Since BedeCorp partially assembled my fuselage, they installed the landing gear so that the plane could be rolled onto a flatbed trailer for shipping to me. The main landing gear attaches to a gear box which sits on top of the floor. The nose gear attaches to several brackets which are also positioned on top of the floor. Finally, I had to remove a couple of gussets from the rear of the cabin area.

The metal for the floor, 48″ x 72″ and just 0.020″ thick, came rolled up in a box 15″ on a side. The first actual “floor task” was to trim sheet down to 46″ x 62″. I got an air shear from Harbor Freight and it made quick, easy work of the cutting.  The slow part was measuring, re-measuring, and re-re-measuring to be sure that I was not mis-cutting this large piece of metal. Had I goofed, the replacement would have been costly and the shipping more so. Fortunately, all went well and the floor fit just fine on the first try.

To insert the floor into the base of the fuselage, Candy and I gently bent it in half and slipped it through a gap near the rear of the cabin area. Think of a process somewhat like slipping a letter into a mail slot and somewhat like putting your foot into a sock and you will have the right idea.

Candy had a brilliant idea to keep the floor from sagging as we worked with it. We took a 2×4 and used my spring-loaded stool to press the board up against the bottom of the fuselage. It made a perfect support for the middle of the floor.

With the floor in the fuselage, I drew a line 1″ in from the edge, all the way around. By drilling rivet holes through this line, the rivets would be in the middle of the 2″x2″ angle of the fuselage on which the floor rests. I then used the rivet spacer tool to evenly space the rivets 2″ apart, all the way around the cabin area.

I bolted the gear box back into the fuselage. I drew rectangles on the floor for holes for the gear legs, using the holes in the gear box as templates. David and I also drilled rivet holes on 1″ spacing through the bottom of the gear box and the floor.

I had to do a little side work, installing nut plates in the angle bracket at the front of the cabin floor, so that the nose gear bracket could be bolted to the angle bracket.

I  then bolted the angle bracket to the fuselage and the nose gear brackets to the angle bracket. This locked the angle bracket in place so that I could accurately drill the rivet and bolt holes through the floor and the angle bracket. I also drilled bolt holes through the floor to match those in a couple of nose gear brackets.

With all of the holes drilled, Candy and I removed the skin from the fuselage. All of the rivets would be countersunk (flush mounted), so in addition to the usual deburring work, I needed to dimple the skin and countersink the thicker aluminum pieces.

Dimpling is easy. Start with a dimple die set, one concave and one convex with a pilot pin sticking out of it. The pin centers the convex die over the hole. Whack the die with a hammer and poof! you get a neat dimple in the sheet metal, perfectly smooth and perfectly sized for the rivet.

Countersinking the metal is easy, too. The tool looks much like a fat drill bit, or a wood countersinking bit, but it has a smooth pilot pin sticking out of the middle. The pilot pin gets inserted into the rivet hole and keeps the countersink bit centered over the hole. The countersink bit gets screwed into a micro-stop which gets adjusted to exactly the desired depth. Pop the micro-stop, with countersink bit, into a drill and hit each rivet hole.

All of the rivets were to be installed from the bottom of the plane so the “bump” would be inside the fuselage and the outside skin of the Bede BD-4C would be smooth. Around the outside edges, the floor sits on top of the fuselage so, the rivets (being shot upward) would go first through the 0.063″ thick angle and then through the 0.020″ thick floor. The metal of the angles is thick enough that it could be countersunk.

Rivet holes for the gear box and the angle bracket at the front of the cabin area needed different treatment, though, since both the gear box and the angle bracket sit on top of the floor. This means that the rivets will penetrate first the thin floor and then the thicker material of the box and bracket. Since the 0.020″ floor is too thin to countersink, it gets dimpled. The metal on top of the floor needs to be countersunk to accept the dimple.

Countersinking all of the holes in the bottom of the fuselage and the gear box was easy but I was covered in aluminum shavings, since I had to do it all on my back underneath the plane. I will probably be picking bits of aluminum out of my beard for months!

Once all of the holes were deburred, countersunk or dimpled, it was time to see if the floor would fit. We slid it back into the fuselage and was I ever relieved to find that it did, indeed, fit. I had missed a couple of bolt holes but quickly drilled them. I also needed to slightly adjust the size of the large holes for the gear legs but, again, this was a quick fix.

David did yeoman’s duty with the rivet puller underneath the plane, easily installing 3/4 of the rivets. The floor, once riveted to the fuselage and gear box, is beautifully smooth and a delightful end to a long week’s work.

The (almost) finished rudder

I have finished the rudder of my Bede BD-4C! Well, almost finished the rudder. It still needs the counterbalance on the top and the weldment on the bottom. And it needs to actually be riveted together. But, other than those trivialities, the rudder is done. The two skins are trimmed to size. The piano hinge is trimmed to length. The three ribs fit. All of the rivet holes have been drilled in all of the parts and everything has been deburred.

Getting to this point was a full weekend’s work.

I started from the happy point of realizing that my newly designed ribs did, indeed, fit properly. Installing the top and bottom ribs would be easy, since I could reach them which the rudder skins were “closed” up. The middle rib would be the challenge so I decided to install that one first.

I began by taping the rib into position in the middle of the inside of the rudder.

The VS-10 rib taped approximately in position in the middle of the rudder.

I then drilled holes through the flange on the end of the rib and the VS-17 spar (which is along the edge of the rudder skin, farthest away in the photo above) and clecoed the rib to the spar.

With the rib held in place in the middle of the rudder by the cleco and the tape, I carefully drew a line on the outside of the rudder skins  along the top of the rib.

I transferred the line along the top of the VS-10 rib to the outside of the skin.

Knowing the length and width of the flanges on the rib, I was able to measure down from the line on the outside of the skin and drill through the skin to where the rib would be. Next, I drew a line down the middle of the rib’s flange and positioned the rib so that the line showed through the holes in the skin. I then drilled through the rib and, voila, it fit. The red line on the skin in the photo below is in the middle of the flange, which is under the skin.

I closed up the rudder (attached the right side skin) and drilled through the skin and the rib using the line that I had previously drawn.

I repeated the process through the skin on the other side of the rudder and, even though I could not see the rib, everything worked perfectly.

With the middle rib held in place with clecos, and more clecos holding the trailing edge together and the leading edges of the skins to the VS-17 spar, the rudder was pretty rigid. Inserting the top VS-15 and bottom VS-9 ribs was easy compared to the middle rib.

VS-9 rib in the bottom of the rudder. This was easier to position than the VS-10 middle rib since I could reach it and see it with the rudder skins assembled.

The final steps were to trim everything to size, enlarge the holes to 1/8″, and debur all of the edges and holes.

I have more pictures, with captions, over on my photo gallery so click to see  the rest of the rudder assembly photos.

Next task: installing the floor.

Fortune smiled on me when it blocked me from making the third rib. I would have had to make it again, along with the other two ribs, and that would have required getting another piece of 0.032″ metal.

When the Bede BD-4C plans were originally drawn, in 1969, the rudder skin was to be made from a single sheet of aluminum. Since it is pretty difficult to find a shop which can cost effectively make the sharp bend in the trailing edge. BedeCorp now recommends that you build the rudder from two skin pieces with a doubler strip between the trailing edges of the two skins. Since the two skins are riveted together at the trailing edge, it pinches the skins and makes the space inside the rudder smaller than originally planned. This means that the ribs need to be both shorter and taper at sharper angles. Because of the change in geometry, you cannot just take an original, long rib and shorten it. Were you to do so, it would be too fat at the trailing edge.

Here is a photo of the parts that I have so far. Click any of the photos to jump to my photo gallery where you can view larger versions of the pictures.

6 rudder pieces: VS-17 front spar, right side skin, tailing edge doubler, left side skin, and two of the three ribs.

Since the rudder skins are oddly shaped, it is hard to imagine how these fit together so the following pictures should help.

The spar and two of the ribs sitting in position on the right side skin. The leading edge of the rudder is on the left, the trailing edge on the right.

The bottom rib is short enough to let the trailing edges of the skins come together. The middle rib, farther away in the picture, was made from the original plans. You can see that it is too long.

To continue assembling the rudder, we lay the doubler strip, visible on the right side of the photo above, onto the trailing edge and then put the second skin on top.

The left side skin (top) clamped to the top of the spar. You can see the doubler between the trailing edges.

Here is a picture with the trailing edges clamped together. You can see that the new VS-9 rib fits neatly into position.

The trailing edges are clamped together and the VS-9 bottom rib inserted into position.

How far off, you may be wondering, was the size of the original bottom rib? Quite a bit.

Two versions of the VS-9 bottom rib. The original (on top) is too large for the new rudder. The new VS-9 is underneath.

Since there are no drawings for the new ribs, I designed my VS-9 by measuring the rudder. I put the two skins and the spar together with clamps and then used a caliper to measure the thickness by the spar. I wanted the narrow edge of the rib to be 0.25″ so I used the caliper to find the point where the skins were 0.25″ apart and then I marked that point on the skin. Finally, I measured the distance, 10.1″, from the spar/fat end of the rib to the narrow end.

I sketched that, added some more metal around the edges for the flanges, and then drew it neatly onto a sheet of aluminum. I cut it out, bent it, and voila, it fit perfectly.

I have the measurements for the other two ribs so I will spend the next couple of evenings fabricating them.