Archive for category Main Structure
Left Flap Hinge and Left Nav Lights Completed (7/3/11)
Posted by Ethan Jacoby in Construction, Flaps, Main Structure, Wings, Wingtips on July 3, 2011
2.7 Hours -
This morning, I managed to get a couple of hours of work in on the RV project. During that time, I finished attaching the left flap hinge to the wing. As with the right side, I had to remove the temporary rivets from the skin/flap brace, deburr as needed, then rivet the hinge to the wing. Once that was completed, I cut the hinge pin in half, bent it to the proper shape, and fabricated another hinge pin retainer. The flaps are officially done!
Just like the right side...the left flap hinge pin and retainer are finished.
Later in the afternoon, I decided to finish up some wiring tasks on my left nav lights. I already wired the LEDs together, but I hadn’t yet attached the power leads. I decided to make the power leads two feet long. This is much longer than I need, but I would rather have them too long for now. I’ll shorten them when the tips are ready to go on the wing. Before I soldered the wires to the LEDs, I drilled a 1/4″ hole in the back plate for a grommet that the wires will pass through. Then, I soldered the wires to the LEDs, and I’m happy to say that my soldering is getting better (it’s still not very pretty though). With the power leads in place, I hooked them up to the driver and fired them up. As usual, I forgot how bright they are and stared right at them as I cranked up the power. Since the lights are in parallel strings, and the driver supplies 1000mA, each string sees 500mA. Even in this slightly under-driven state, they’re still brighter than any nav lights I’ve seen on a factory built plane. Once I remove the protective paper from the mirrored plexi, the mirror should amplify their apparent brightness.
The power wires were soldered to the LEDs, then passed through a grommet. They'll connect to a driver that will be attached to the outboard wing rib.
As a mild test of heat generation, I left the LEDs on for about 10 minutes. The back plate started to warm up a bit, but it was by no means getting hot. I had already ordered a couple of heat sinks, and, once they arrive, I think I’ll go ahead and install them on the back side of the aluminum plate just to be safe.
All six LEDs lit up. Very bright...the camera doesn't do them justice.
The LEDs with the mirrored plexi in place. The protective paper is still in place, but I think they'll look even brighter when the mirror is uncovered.
Right Flap Hinge Pin Retainer Finished (6/27/11)
Posted by Ethan Jacoby in Construction, Flaps, Main Structure, Wings on June 27, 2011
0.8 Hours -
Thinking it would be a little cooler, I went into the garage at about 8pm. Unfortunately, it was so hot (even with a fan blowing directly on me) that I could only tolerate it for about an hour…just enough time to finish the retainer for the right flap hinge pin.
The most difficult part of this process was riveting the nutplate to the flap brace. I couldn’t figure out a way to access the rivets for bucking/squeezing, so I ended up using MK-319-BS blind rivets instead. They don’t sit as flush as solid rivets would, but no one will ever see this unless the flaps are off. If I had some on hand, I probably would have just used a #6 nylok nut, but I’d rather use what I have on hand than place a $0.50 order that costs another $10 to ship.
Once the nutplate was installed, I drilled a hole in the hinge eyelets that will capture the pin. Then, I did a test fit and clipped the ends of the pin to the necessary length. At some point, I’ll probably do a little finishing work on these to make the ends even and remove any barbs, but this system should work well.
The last thing I did was attempt to reinstall the right flap. To ease pin insertion, I put a dab of Boelube on the hinge eyelets. However, I quickly realized that the way my wings are positioned in the cradle will make flap attachment a two person job. I couldn’t hold the flap in place and reach around to the other side to push the pin in blind. If the wing was oriented as it will be on the finished plane, I don’t think one-person installation/removal would be difficult.
The completed hinge pin retainer on the right flap. Not bad for homemade.
Another view of the pin retainer.
More Wingtip Work and Right Flap Installed (6/12/11)
Posted by Ethan Jacoby in Ailerons, Construction, Flaps, Main Structure, Wings, Wingtips on June 12, 2011
2.5 Hours -
With today’s work session, I passed the 500 hour mark on the build. This means I’m anywhere from a third to a fifth of the way finished as far as build time goes.
I started the day off by working a bit more on the wingtip cutouts. I had already transferred the pattern to some sheet aluminum, so I used my band-saw to cut the pieces out. Once cut out, I did some edge finishing with both a belt sander and a Scotchbrite wheel. However, I won’t be able to finalize the shape until they are bent and I can hold them in place on the wing.
The left wingtip cutout before bending. I also made one for the right since it is just a mirror image.
Since I had the left wingtip on the bench, I decided to go ahead and attempt to bend the left cutout. To do this, I simply used the edge of my workbench and a section of 2″x4″. After a few attempts, I had the angle correct, but the cutout had quite a bit of extra material that needed to be removed. My belt sander made quick work of this and made it easy to keep the curved edge intact on the aluminum. For now, I’ll just use the left cutout to work on making the plexiglass pieces and figuring out the LED arrangement. Once everything is finalized, I’ll come back and finish the right.
After bending the cutout, I had to do a little trimming and finishing to get it to fit correctly.
Next on my to-do list was to get the flaps installed. Since the right aileron has been neutralized, and the bellcrank jig was still in place, I decided to start with the right flap. The biggest problem with mounting the flap is that there is a gap between the bottom wing skin and flap brace if no clecoes/rivets are installed. To eliminate this gap while aligning and drilling the flap hinge, I used a method that I found on a build site called Matt’s RV-7 Project. However, he gives Dan Checkoway credit for the idea.
The basic idea of this method is to eliminate the gap temporarily by installing several oops rivets (NAS1097). These rivets will be flush on the flap brace side during initial flap mounting. Then, before riveting the flap hinge to the wing, the oops rivets are drilled out and reversed so that the flush head is now on the skin side of the wing. To make this work on my right wing, I ended up drilling holes for 7 oops rivets. After manually countersinking the flap brace, I squeezed the oops rivets in place, and the gap was gone. With the gap closed, I could easily set the flap in position and clamp it with two side-grip cleco clamps.
I drilled 7 holes through the bottom skin and flap brace in each wing for temporary rivets.
The flap brace is countersunk for an oops rivet. After mounting the flap, I'll drill out these rivets and re-insert them with the flush head on the skin side.
Two clamps held the flap in position while I adjusted it. Here's the outboard clamp near the aileron hinge.
The inboard clamp was much easier to install and adjust compared to the outboard clamp.
With the flap now clamped in position, I could make small adjustments, nudging the flap inboard/outboard, up and down, until the trailing edge was aligned with the trailing edge of the aileron and there was a 1/4″ gap between the flap and aileron. Before starting to drill I had to make sure I would have enough edge distance on the wing side of the hinge. Since I previously drew a line on the hinge indicating minimum edge distance, DO NOT CROSS, it was a simple matter of glancing through the holes in the wing skin to see where the line was. The line was barely visible at the forward side of the holes, so I had more than enough edge distance. I was partly surprised by this since I’ve read so many accounts of builders having to order a wider piece of hinge stock in order to meet the edge distance requirement. I can only hope the left wing works out the same!
The right flap hinge is now drilled to the wing. No hinge edge distance issues here!
The gap between the flap and aileron is a perfect 1/4" the entire length.
Since everything was lined up perfectly on the right flap/wing, I decided it would be good to take a lunch break before drilling the hinge and then return to double-check the alignment with fresh eyes. After lunch, I remeasured the flap to aileron gap, double checked the trailing edges were in-line, and re-checked that my edge distance would be more than sufficient. With everything still satisfactory, I started drilling at the outboard end of the flap. Since the flap was only being held in place by two side-grip clamps on the hinge, and a bigger clamp holding the flap in neutral position with the aileron, I started drilling very cautiously and with very little pressure on the drill. After the first hole was drilled and clecoed, I, once again, checked that everything was still in the correct position before proceeding to the next hole. I continued this way for sever holes. Then, when I felt the flap was sufficiently held in place with clecoes, I picked up the pace ever so slightly. A few minutes later, the flap hinge was completely drilled and clecoed. As usual, something I was really worried about working came out great.
Of course, now that the right flap is drilled, I have to repeat the entire process on the left wing. For today, I managed to install the bellcrank jig and get the left aileron neutralized, and I also installed the 7 temporary rivets in the flap brace and wing skin. At the next work session, I’ll be ready to align the left flap and drill the hinge.
After a couple twists of the pushrod ends, the right aileron was aligned. The angle isn't on the center of the aileron's trailing edge since it is aligned with the side of the bolts.
Pushrods Finished (5/8/11)
Posted by Ethan Jacoby in Construction, Main Structure, Wings on May 8, 2011
More pushrod work today, but now I’m done with them.
I started by priming the outside of the W-716 pushrods. Now that these are primed, they can basically be set aside until its time to mate the wings to the fuselage. However, they’ll get stored in the wings, partially installed.
After the W-818 pushrods were assembled, I primed them with some NAPA 7220.
Next, I finished fabrication of the W-818 pushrods. These rods needed to be drilled so that the end caps could be riveted on. I decided to drill the rods, then install the caps and use the holes in the rods as guides for drilling the caps. This seemed to work fairly well. Once all the holes were drilled, I started riveting. Because of the width of the assembly, I couldn’t use my pneumatic squeezer. So, rather than trying to buck the big 4-12 rivets, I opted for using my hand squeezer. Even with the hand squeezer, I bent over several rivets (-12 is probably too long here) and had to drill them out.
The W-716 pushrod ends installed.
Once the W-818 ends were finished, I installed the rod end bearings and jam nuts, and adjusted the bearings until the push rod was the proper length. Then, I installed the pushrods in the wings. The bellcrank end was easy to install, but the aileron end was a real pain since my wings are in the cradle and I can’t easily access the top side. However, after several attempts, I finally managed to get everything installed. All the nuts are only loosely installed for now since everything will have to come apart again after the flaps are installed. I also installed the bellcrank neutral position jig in the right wing. Now, I’ll have to figure out how I want to make a jig for insuring that the ailerons are neutral.
The W-716 pushrod bearings installed.
A W-716 pushrod installed in the right wing along with the bellcrank neutral position jig.
The right wing's bellcrank, neutral position jig, and W-716 pushrod.
Attaching the W-716 pushrod to the aileron was a bit of a hassle only because of the position of the wings in the cradle.
More Pushrod Work (5/7/11)
Posted by Ethan Jacoby in Construction, Main Structure, Wings on May 7, 2011
0.5 Hours -
There wasn’t much time for working on the plane today, but I managed to squeeze in a half hour. During this time, I installed the end caps on the W-716 pushrods. The ends are installed with 6 blind rivets on each cap. I still need to prime the outside of the tubes, but that will wait until tomorrow.
The W-716 pushrod ends are installed with 6 blind rivets. A rod end bearing will screw into this.
I also did a little work on the ends for the W-818 pushrods. The ends are a bit to large for the steel tube, so I have to remove some material. For this, I’m using my belt sander, but the ends get hot quickly and I had to set them aside for until they cool back down.
Aileron Pushrods Continued (5/6/11)
Posted by Ethan Jacoby in Construction, Main Structure, Wings on May 6, 2011
1.3 Hours -
Tonight, I started working on drilling the aileron pushrods. On both sets of pushrods, the ends have to be drilled to fit threaded caps. Rod-end bearing will attach to these caps.
To drill the longer, W-716, pushrods, I made a paper template for marking hole locations. To mark the tube, I placed the end over the template and transferred the location of the lines to the tube. The caps will attach with 6 blind rivets, so they need to be spaced 60 degrees from each other if I want the spacing to be even. With the help of my drill press jig, I only had to drill three times since the jig ensured that I was always drilling two holes, 180 degrees from each other. The spacing turned out pretty good.
I used this template to mark the pushrods for drilling. Each line is 60 degrees apart.
An end view of the pushrod after drilling. The alignment of the holes doesn't really matter, but these are perfect!
Another view of the end of the pushrod after drilling.
Next, I cleaned the inside of all four pushrods with acetone followed by compressed air. Then, I shot primer down the inside of the tube while rotating it. It isn’t the best way to apply primer, but at least the inside is coated. I’ll prime the outside of the longer tubes once the caps are installed.
Finally, I cleaned and primed the end caps for the W-716 pushrods.
I primed the insides of the tubes and the caps. The outside of the tubes will get primed later.
Aileron Pushrods Started (5/3/11)
Posted by Ethan Jacoby in Construction, Main Structure, Wings on May 3, 2011
0.8 Hours -
We had a cold front blow through South Texas, so I figured I better get some RV building time in while the temperatures are below 80. Unfortunately, I didn’t have much time this evening. However, I did manage to get the aileron pushrods cut to length.
The W-716 pushrods are constructed from a piece of AT6-035 x 1.125 aluminum tube that has to be cut into two pieces that are each 65-25/32″ long. 65-25/32″ is a bit difficult to measure so I measured to 65″ with a tape measure, then added the 25/32″ with a small scale. Once I marked the distance, I re-measured and re-measured again before making the cut. Cutting the tube was the easy part, as I simply used a tube/pipe cutter. The process was repeated for the second tube, and I ended up with about 10″ of extra material. If I were building an 8, I believe the pushrods would be longer, and no excess would be left over. I guess it is easier for Van’s to only supply one length.
W-716 pushrods cut to length. Van's gives you close to a foot of extra material.
Next, I made the W-818 pushrods. These pushrods will connect the larger pushrods to the ailerons, and are constructed from 4130 x 1/2 steel tube that has been powder coated. These are significantly shorter than the W-716 pushrods at 23-13/16″, which makes them much easier to measure. As with the other pushrods, I used a tube/pipe cutter to cut the stock to size. However, there was only about 1/2″ of extra material included on this piece.
W-818 pushrods cut to length. Unlike the W-716 pushrods, there is only about a half inch extra material for these.
Finally, I set up the pipe drilling jig I bought for my drill press about a year ago. This little tool was bought specifically for drilling these pushrods, but it has sat on my workbench, unused, for almost a year. Using an excess piece of aluminum tube as a test piece, I quickly drilled two holes. The jig did it’s job and the holes were exactly opposite each other. Now I just need to mark the ends of the pushrods and drill some holes.
I finally got to set up the drill press tube drilling jig that I've had for about a year now. This should simplify drilling the pushrods.
More Left Flap Work and Aileron Installation (3/27/11)
Posted by Ethan Jacoby in Ailerons, Construction, Flaps, Main Structure, Wings on March 27, 2011
4.0 Hours -
About half of my time in the garage today was spent deburring the left flap skins and dimpling anything I could reach with my squeezer. However, I got stuck on about 4 holes on the top skin. I can’t find any way to dimple the aft-most holes because the bend in the skin is so tight that nothing I have can get in their. So, as I thought about what to do, I moved on to other items including priming the FL-706A & B (these will be the only flap parts that get primed) and installing the ailerons on the wings.
On the ailerons, I decided to start by installing the bellcranks even though I don’t have any of the push tubes completed. To install these, I had to remove both bellcrank brackets and re-drill them to 1/4″. Apparently, the drill bit I used originally was slightly undersized and the AN4 bolt wouldn’t go through. I was going to have to remove at least the top bracket anyway, so removing both wasn’t such a big deal.
After re-drilling the brackets, I reinstalled the lower bracket, then slid the bellcrank bolt through the top bracket, bellcrank bushing, bellcrank and lower bracket. Before installing the bushing, I lubricated it with some Aeroshell 33. Van’s just says to use your preferred grease. Since I don’t have one, I decided on Aeroshell 33 since it advertises itself as and all-purpose airframe lubricant.
The aileron bellcranks were easy, but time-consuming to install since parts of the bracket have to be removed to insert the long bolt.
Next, I installed the ailerons on the wings. First, I had to make a spacer for the lower end of the inboard aileron bracket. This spacer was just a piece of tubing stock cut to the appropriate length. Actual installation of the ailerons was simple, but sliding all the washers into place is a bit of a pain. It was nice to see the ailerons in place. For some reason, they make the wings look more like wings!
The ailerons are attached to the inboard bracket using a spacer and several washers.
The aileron is attached to the outboard bracket using several washers and there isn't much room to work.
The outboard end of the wings with the ailerons installed.
Another view of the aileron on the right wing.
Flaps Started (3/20/11)
Posted by Ethan Jacoby in Ailerons, Construction, Flaps, Main Structure, Wings on March 20, 2011
3.3 Hours -
At first, my plan for the day was to mount the ailerons on the wing. With this in mind, I started working on the aileron bellcranks. I drilled the holes in the bellcrank to the proper size for AN3 bolts. Then, I pulled out the brass bellcrank bushings and used a 1/4′ drill, chucked in my drill press, to open up the bushings for AN4 bolts. After doing this, I rethought my plan for mounting the ailerons and decided to switch to building the flaps. No real reason for this change.
I started the day by working on the aileron bellcranks. I got as far as drilling the bellcrank bushings to size, then decided it would be better to wait on the rest until I'm ready to install the ailerons on the wings.
My flap work for the day consisted of a lot of deburring and fabrication. By the end of the work session, I had everything made that is fabricated by the builder (not much), and I completed the edge finishing on all the parts except for the skins.
On to the flaps!
First up, I finished the edges of all the ribs. This includes four FL-704 exterior ribs and eight FL-705 interior ribs. These were finished using only my large Scotchbrite wheel mounted in the drill press.
Here's a pile of flap ribs after deburring their edges.
After the ribs, I needed a little break from deburring, so I fabricated the FL-708 spacers. These spacers will be placed at the bottom, aft of each of the exterior flap ribs to fill a gap between the skin and the rib. As usual, Van’s provides a full-scale drawing with detailed dimensions for parts that the builder fabricates. Since this part is nothing more than a small rectangle of .025 alclad, I didn’t have to rely on the drawing too heavily! To make the spacers, I cut them from scrap aluminum using my bandsaw, and then finished the edges on the Scotchbrite wheel.
The FL-708 spacers (2 per flap for a total of 4) had to be fabricated from scrap aluminum...fairly simple stuff.
Four FL-708 spacers ready for drilling.
Next, I deburred the edges of the FL-703 spars. The long edges were easy to finish using the large Scotchbrite wheel, but the small lightening holes are more of a pain. For these, I used a combination of tools including a swiveling edge deburr tool, small Scotchbrite wheel in a die grinder, and a maroon Scotchbrite pad. Fun stuff (not really)!
The flap spars after deburring...the lightening holes take a significant amount of time to deburr.
With the spars deburred, I moved on to the FL-706B plates. These plates are made from thick aluminum and they reinforce the area where the flap actuator mechanism attaches to the flap. Since these are made from thick stock, I first filed the edges with a vixen file to remove all the marks left from fabrication at the factory. Then, I ran them through the big Scotchbrite wheel to knock of the corners and polish the edges. These parts will be given a slight bend later on, so I went ahead and marked the bend line now. One will be bent up approximately 6 degrees and the other down 6 degrees in order to create a left and right part. The actual bending shouldn’t be difficult, but it’s going to have to wait for another day.
I deburred the FL-706B plates and marked were they are to be bent. One goes up 6 degrees, the other down 6 degrees.
The final thing I did today was to fabricate the FL-706A angles. These are used in combination with the FL-706B plates to reinforce the area of the flap where the actuator is attached. As with the FL-708 spacers, a detailed drawing with dimensions is provided, and it is up to the builder to cut these from supplied angle stock. Again, these are fairly simple parts. The angle stock is cut to the appropriate length. Then, the short side of the angle is cut down even further. Finally, the parts are deburred using a combination of a vixen file and Scotchbrite wheel.
The FL-706A angles have to be fabricated from this piece of stock angle.
As usual, Van's provides dimensions for parts that the builder fabricates. Here's the FL-706A drawing.
The FL-706A angles after cutting to size and deburring the edges.
With all of these parts prepped, it should be a relatively quick process to finish up the flaps. The only thing I’m not looking forward to is dealing with the flap hinges.
Skin Prep Finished and Pitot Tube Assembled (2/19/11)
Posted by Ethan Jacoby in Construction, Main Structure, Wings on February 19, 2011
3.4 Hours -
There are a lot of pictures for this post. Some of them may seem a little repetitive on the pitot/AOA portion, but I wasn’t able to find many good descriptions for assembling the Dynon pitot/AOA with the SafeAir1 mast. Hopefully, my description and pictures will help out someone else.
Since deburring doesn’t make any noise that will wake up the neighbors, I started on the project relatively early this morning . OK, it probably wasn’t early by most people’s standards, but I know some people were still asleep in the neighborhood. After about a half hour, I had all the holes on the left bottom outboard skin deburred. Once deburred, I transitioned to dimpling and used my squeezer to dimple all the holes that it could reach. By this time, I figured it was late enough to start making some noise, so I pulled out my c-frame to finish the dimpling process. To wrap up my morning session, I scuffed cleaned and primed the inside surface of the skin.
Me, deburring the left bottom outboard skin.
A bonus picture for the FAA. Me, dimpling the left bottom outboard skin.
After lunch, I returned to the garage. Before I could start riveting the left bottom outboard skin, I needed to finish the pitot assembly. This could be done after the skin is riveted, but doing it now lets me see how things are going together inside the wing. Once the skin is riveted, I’ll just have to attach the pitot tube to the mast and connect the air lines.
The first thing that needed to be done was to match drill the mast and pitot. Unfortunately, neither of these have any holes to use as initial guides. The only indicator of hole location is on the pitot tube itself, where there are areas with thicker metal that indicates the proper location for the holes. I used a sharpie to draw lines on the outside of the tube where these thicker areas were. I could then insert the tube part way into the mast and transfer the lines to the mast.
The pitot tube has to be drilled through the sections that have extra metal...marked with lines here.
I transferred the lines to the mast, since I would have to drill through the mast first.
To drill the holes, I started with the mast. After some careful measurement to determine the proper distance that the holes needed to be from the end of the mast, I center punched the mast and drilled the initial holes to #40. These will have to be enlarged, but not until I know everything is lining up.
I drilled the initial holes to #40. These will be enlarged once I know everything fits.
With holes drilled in the mast, I reinserted the pitot tube. The lines on the tube were visible through the holes in the mast, so I knew the holes were in the right position. The pitot tube was a little loose inside the mast, so I wrapped a couple layers of aluminum tape around it before drilling. These two, thin layers of tape gave the pitot enough extra thickness for a tight fit in the mast.
The lines on the pitot tube are visible through the holes in the mast. This is a good sign, but I'm still nervous about drilling into a $200 part!
I then drilled the holes in the pitot using the mast holes as a guide. I did this extremely slowly because, if I was off, I could easily drill through the tubing inside the pitot. If this were to happen, the pitot would be ruined ($200 down the drain). After drilling the holes in the pitot, I tapped them for #6 screws.
After drilling the holes into the pitot tube, I tapped them for #6 screws. I also placed two layers of aluminum tape around the pitot to give it a snug fit in the mast.
Next, I enlarged the holes in the mast in order to accommodate #6 screws. I opted for flush screws, so I needed to countersink the mast. Since the mast is curved, a countersink cage would not work, and I decided to countersink by hand using a deburring tool. This method doesn’t create the prettiest countersinks, but it gets the job done.
Since the mast is curved, I had to countersink for #6 screws by hand with a deburring tool.
After countersinking the mast, I assembled the pieces for the first time and everything went together easy and the hard part was behind me!
The pitot tube and mast assembled for the first time. This wasn't nearly as difficult as I thought it would be.
I’m using the SafeAir1 pitot/static and AOA tubing kits. These kits use plastic tubing, while the Dynon pitot/AOA has aluminum tubing. To connect the two types of tubing, SafeAir1 provides the appropriate AN and push-on fittings. To install these, I cut the tubes on the pitot/AOA to the appropriate length. For this, I decided to cut them so that the coupling hardware would be partially inside the pitot mast. Once cut, I used my Rolo-Flair to flare the ends of both tubes. After that, it was just a matter of installing and tightening the fittings.
The ends of the pitot and AOA tubes had to be cut to length and then flared. My Rolo-Flair made quick work of that!
The SafeAir1 hardware enables a transition to plastic lines using push-on connectors.
Here's the finished product off the wing. I'll probably wrap the fittings with some tape so they aren't vibrating against each other or the inside of the mast.
To wrap up the day, I did one last test fitting of the assembled pitot/mast on the wing, and then I clecoed the left bottom outboard skin to the wing. Finally, I ran the pitot and AOA tubing into the wing just to see how it would work. I’m planning to run the tubing under the bellcrank, and I may need to install an adel clamp to hold the tubing down and prevent it from rubbing on the bellcrank. I’ll wait to do this until the bellcrank is installed and I can see how things are actually going to work.
Here's what the pitot assembly will look like on the wing.
Both wings are now ready to have the final skin riveted!
Just for fun, I ran the pitot and AOA lines. I will run them under the bellcrank. If needed, I'll install a clamp to hold them down and prevent them from rubbing on the bellcrank.
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