Building the Left Wing Stand

I picked up some Tapcon screws from Home Depot to use to anchor the wing stands into my concrete floor.  These things are pretty dang nice!  They worked great.  More about them later.  Tonight we finished up the left wing stand.  Just like the right stand, we got it leveled up screwed it into the floor joists.

Then I made up some brackets for the floor out of some scrap Aluminum angle.  After one last check on the stand to make sure its plumb and straight I marked my holes and drilled the hole in the concrete use the Tapcon bit. 

Then I used some lag bolts (5/16 I do believe) to bolt the 4×4 beam to the angle which was held in place by the 1/4″ tapcon screws.  I bought 8 Tapcons in a pack, and then the special Tapcon bit that is used to drill the hole for less than $10.  Drilling the holes took a bit, since I did not have a hammer drill, but I eventually worked the bit down to the right depth, removing it every so often to vacuum up the concrete dust and cool the bit. I didn’t have to use a whole lot of pressue surprisingly, and the holes were nice and straight.  The Tapcons threaded right in like the holes were machined for them.  They clamped down with a good bit of force too.

Then I leveled up my spar mounting arms to get ready for the spars.  My adjustable screws made this really easy to do.  I’ll check it again when the spar is on to see if I have any twist or uneveness.

I did both sides of my left stand, and it is ready to have the spar mounted.  I need to move some stuff around before I get to that point, so my next “build session” will be me cleaning up and getting stuff moved out of the way.  Heres some shots of the beams ready to go!

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Hours worked: 2.0

Building the Right Wing Stand

There is no more delaying it.. I have to build the wing stands.  I have done everything I can on the wings to the point of needing to get the spars on the stands.  I spent some time trying to visualize where to best put these things, and what would give me the most working room.  I built the uprights using 2 2×4 beams that would reach up to the floor joists in the ceiling.  This would give me a solid place to mount them.  For the floor, I will drill some holes in the concrete and use some angle brackets to anchor them down.  They are not anchored yet, I need to get a good masonry bit and/or a impact drill.  Here’s where I decided to put the right wing stand and the uprights are screwed in to the floor joists.

And here I have drilled the hole for the 3/8 bolt that will go through the upright to hold the horizontal arms that the spar root will clamp to.

I drilled the holes for both sides and then the uprights were about halfway done.  I took a quick break for some food, and came back down to finish up the mounting system for the wing spar.  I used the Vans recommendation, in addition with some other folks on how to make the horizontal arms adjustable so I could easily level and work the twist out of the spar by adjusting the “jack screw” to raise and lower the horizontal arms.

It works really well.  That is just some 3/8″ all-thread rod I trimmed down and then I cut up some scrap angle aluminum to make the brackets the all-thread goes into.  Then some 3/8″ nuts to act as jam/adjusting nuts and I have a solid and adjustable mounting system for the wing spars.  On the end of the wing I had to get a little more creative due to how we have to use the wing’s end rib and some angle to mount it. but it still works out pretty good.

The all-thread comes up through the horizontal arm at an odd angle, but with the jam nuts I am still able to adjust it up and down enough.  And, I will have some adjustment on the other pieces of angle that get bolted to the wing’s end rib per the plans.   I still need to cut some angle to use to bolt the bottoms of the uprights to the floor, but I will wait until I have both the left and right wing stands ready so I can rent a hammer/impact drill and a concrete bit to drill the holes in the floor for a solid mount.  That pretty much wraps it up for the right wing stand.  I spent a little over 3 hours on it, but the left wing stand should go much quicker as I worked out all the bugs and layout on the right one 🙂 Here’s all the photos from tonights session:

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Google Photos Link:

Hours Worked: 3.25




Finished up Alodining the Wing Ribs

Holy crap…its been a LONG time since I did any real work on the RV-7.  Like nearly 7 months.  Life’s been a bit busy, I bought a 1973 Cessna Cardinal 177RG and have been flying the wings off of it, and that has taken up some time on the build, in addition to work, and family.  But, with the daylight hours dwindling, and flying weather getting sparse, its back to building!

Anyways, the last place I left off, I had to finish up Alodining some wing ribs, and then get my wings in their stands.  I ended up going down to Aircraft Spruce a few months back (In the Cardinal of course!!) to pick up some more Alumaprep and Alodine.  So I mixed it up tonight.  Here is what I am using for the mix ratios:

Alumaprep bath: 

1 Gallon of Alumaprep 33 concentrate mixed with 3 gallons of distilled water.  Makes 4 gallons.

Rinse the parts off to get rid of dust and grime. Scuff with maroon scotchbrite a little if needed during the rinse.  Then soak for 7 to 10 minutes in the bath.

Rinse parts in cold water to remove alumaprep.

In the photo above, I had to use a rib and a glass jar to help hold down the other 6 ribs.  The bubbles from the Alumaprep during its cleaning causes the aluminum to float!

Alodine bath:

1 Gallon of Concentrate Alodine mixed with 2 gallons of distilled water. Makes 3 gallons.

After the alumaprep bath and rinse, soak parts in Alodine bath for 7 to 10 minutes.  Remove and rinse in cold water to remove excess alodine and then let air dry.

And the obligatory photo that shows to the FSDO that I am actually the sucker building this plane…..apron,, gloves and all.  I did remove my safety glasses for the photo though.

I was able to get all of the wing main ribs and wing end/nose ribs done and set out to air dry. It was good to get back down here and work on this project and start making progress again. I have decided to not spray primer on the ribs, except maybe the nose ribs.  I think I will prime them since they will be fully enclosed and potential traps for moisture. Here’s how they ended up:

And here is the entire photo album from tonights work. Not many photos since it was just alodining.  I think  I will start working on the wing stands next.


Google Photos Link:
Hours Worked:  2

Alodining the Right Wing Ribs

I found a tub that was just big enough to hold two main wing ribs to bathe them in Alumaprep 33 and Alodine!  I was lucky I had JUST enough of each to fully submerge the parts.  I started out by submerging the parts in Alumaprep, 2 ribs at a time and letting them sit for 5 minutes each.

Then I rinsed them off really good and set them shook off as much water as I could.  Right after that, they went right into the Alodine bath to soak for 5 minutes.

The photos only show a single wing rib, which was my test piece to make sure I had enough solution to fully submerge them. I was able to get two at a time in each bucket, and wound up doing an assembly line style workflow.  Two parts in Alumaprep 33 while two other parts were in the Alodine.  This worked out pretty well as I moved the parts from the first bath the second in sucession with rinses in between each.  The Alumaprep gave a real nice sating finish that was very clean:

And here’s how they look after the Alodine bath.  I love that gold color!

I’m going to put these on the shel for now and cover them with a towel to prevent dust from getting on them.  I’ll do the right wing ribs next and once I have all of them alodined, I’ll spray them all with AKZO in one large session for convenience.

Here’s all the photos from Tonights work:

Hours Worked: 1.75

Washing the Right Wing Ribs

Quick entry tonight.  I am still working on my wing stands, more on those in a later post.  Tonight I decided to scrub up my Wing Ribs so they’d be ready for Alumaprep and Alodining later on. Pretty simply, I filled up my utility sink with some Dawn dish detergent and then scrubbed them lightly with a scotchbrite pad until all the crud was free.

The goal was to get a slight scuff on the surface to break any gunk off, and let the Dawn do the work of cleaning.  Once I had them cleaned, I rinsed them off with clear water and set them aside to dry.

I am still going to dunk these in Alumaprep 33 so it can chemically etch the surface as well as let it do a final cleaning, before going in the Alodine. I only did the right wing tonight, because I didn’t want to get these confused with the left wing ribs.  I’ll let them dry and go to Wal-mart to find a tub that they will fit in.  They are just over 27″ long, and won’t fit in my largest tub for the chemical baths.

That’s it for tonight.  I’ll pickup some larger tubs for these ribs, and get them alodined.  Then I’ll repeat the process for the left wing, and shoot them all with primer.

Google Photos Link:

Hours Worked: 1

Drilling Wing Ribs for Wiring and Plumbing

Back on the ribs tonight.  Since I have finished up the control surfaces for the wings, and I am still needing to build my wing stands, the only thing I can work on is the holes for my conduit and pitot and AOA plumbing in the wing ribs.  I have been putting a lot of thought to this issue over the past few weeks, and I have decided to drill two extra holes in my ribs, and enlarge one of the tooling holes. The session started with me looking over the recommended wing wiring diagrams from Vans, and then looking at what other builders have done.  I also unboxed my pitot-static-AOA plumbing kit from SafeAir1 and checked the outside diameter of the tubing used to make sure I didn’t over size my holes.

I have decided to drill the suggested 3/4″ hole at the bottom portion of the ribs, between the forward and second lightening holes per the Vans recommendation. I will run the 5/8″ nylon conduit that Van’s sells in these holes and I’ll use it for the majority of wiring in my wings.  In addition to this larger hole, I am going to drill an additional hole sized to 3/8″ just above the forward and center tooling holes in the ribs.  Then I’ll open the smaller tooling hole to 3/8″ as well, and use these two 3/8″ holes for my pitot and AOA tubing, protecting them with a snap-in bushing.  This illustration gives a better idea of what I want to do:

I will probably not immediately use the existing 1/2″ tooling hole on the forward edge of the rib, but I will probably go ahead and stick in a nylon bushing just in case I want to use it in the future.  I started out by measuring out where I wanted to put the 3/4″ hole. Vans just gives us a suggested location of “towards the bottom of the rib, between the first and second lightening holes”. I did some measuring and decided roughly where I wanted the center of the hole to be. Then I used a #30 drill bit to drill the center.  I then measured our equidistant from the 1/2″ tooling hole at the forward end of the rib and tried my best to get the new hole to be symmetrical to the existing holes.  It really doesn’t matter, so long as I drill the holes in the  same locations (roughly) in each rib.

I drilled the new holes with a #30 to pilot the holes, and then I made a simple jig so I could transfer the holes to the rest of the ribs repeatedly and get the location exactly the same each time. I had a scrap chunk of 2×4 that worked great for this purpose.

I just placed the 2×4 in the bottom corner of the rib, held it securely and transferred the hole I marked and drilled into the board.  I did this for each of the new holes.  Once I had the bottom hole (marked as 3/4″ on the board) drilled in the rib, all I have to do is slide the 2×4 to the top of the rib and match drill the new 3/8″ hole in using the guide marked as “3/8” on the board.

The only catch is this template/jig only works for the “left handed” ribs.  So, instead of making a whole new template for the “right handed” ribs, I just placed the left handed and newly drilled ribs on top of the right handed ribs flanges facing away from each other and back drilled the new holes.

Once I had the new holes drilled to a #30, it was time to enlarge the holes to their final size.  I used a uni-bit (step drill) to enlarge the holes.  I first started out by drilling the 3/4″ hole, using some spare wood blocks to hold the rib above my work bench to give the unit-but room to do its job.  I went ahead and drilled all the ribs 3/4″ conduit hole since it wont interfere with any other build steps.  I even did the inboard and outboard ribs.

Then I enlarged the new 3/8″ hole on all the ribs, including the outboard ribs. BUT, I did not enlarge the existing tool holes on the outer and inner most ribs since they are used for aileron alignment. I’ll leave these for the very very last once I have the control surfaces aligned and mounted.  Here’s what the holes look like once they are all drilled and enlarged to size.

After I had all the holes done, I decided to call it a night.  I need to deburr all the holes, but I may leave that as a job for when I deburr all the other holes. The next thing I HAVE to get done is build my wing stand, since it is now the critical path in my build. Heres all the photos from tonights build:

Google Photos Link:

Hours Worked: 2.5

Finishing the Right Aileron

Not much to report tonight.  I spent about 45 minutes riveting the bottom of the right aileron.  All I had left to do was squeeze a few rivets on the ribs and then pull the blind rivets where the skins meet the spar.  It starts by putting the aileron, bottom facing up, on my flattest work bench, and then weighing it down to ensure it stays aligned, and not twisted.

I found that the center section is just about perfect, and I added a little more weight with my cleco bucket. Once it was weighed down, and I had checked the flatness, I set the blind rivets along where the counterbalance pipe is attached to the leading edge skin, checking the aileron for twist and aligment every few rivets. Next up I squeezed the last few rivets; first along the leading edge skin, and then along the trailing edge.

Once that was done, all that was left was to set blind rivets that join the top and bottom skins to the spar.  The pneumatic rivet puller I bought makes this easy and quick…. $25 well spent. The Right aileron is now finished and is on the shelf. Like the left one, I did not attach the mounting brackets just yet.  I’ll leave them off until I get ready to mount the aileron to prevent damage to other parts.  At this point, I am ready to move on to something else in the build.  I was going to dive into the tanks, but I need the wings on the stands in order to fabricate the mounting brackets.  SO, I guess I will jump back to the ribs, and finish them up and build my wing stands. I need to order some conduit, and some reamers. I need the conduit so I can drill our the holes in the ribs for it to go through. Time to spend some money I guess!

Hours worked: .75

Riveting the Right Aileron

This work session is the exact same as riveting the left aileron. So I won’t go into much detail.  Feel free to browse on over to my blog entry for the left aileron here as well as here  to get all the details. It starts out by riveting the nose ribs to the counterbalance pipe and then fitting that assembly into the leading edge skins, and attaching the spar.

Once that is all done,  I riveted on the nose ribs to the spar, and then fitted the assembly into my holding station to make riveting the top row of rivets easier.

Once I had the trailing edge skin clecoed into the spar/leading edge assembly, I make sure everything was in alignment and then began bucking rivets on the top of the spar/skins.  I am finding it easier to buck rivets with a gun, and am pretty happy with the results….most of the time.

Using an edge forming tool to break the edges of the leading edge skin really makes for a very nice and flush lap joint on these two skins:

The next step was to rivet the top half of the nose ribs to the leading edge skin and then insert the end ribs.

Then, Vans has us rivet the top half of the trailing edge skin to the end ribs, making sure to use the AN426AD3-4 rivet where the skins, ribs and spar come together.  All the other rivets are the regular AN425AD3-3.5.  I used my squeezer to set these rib rivets since they are easy to get to.

Once I had all the top half of the aileron riveted, the only thing left was to weight it down and rivet up the bottom half. I decided to end it there for tonight.  Was getting a little tired, and it’s never good to do final riveting when you’re tired.  I’ll set the aileron up on my flattest bench, weigh it down and rivet the bottom rivets another time.  Here’s all the photos from tonights work:

Google Photos Link:

Hours Worked: 2.25

Finishing Riveting the Left Aileron

I ended up scoring a decent little pneumatic rivet puller / gun from Harbor Freight for $25 after the coupon during their sale.  This will save me some labor on ALL those blind rivets along the bottom of the ailerons.  Lets put it to use! I don’t like very much work on finishing the left aileron, so I jumped in right where I left off last night and scavenged around to find some sort of weight to hold the aileron down on my flattest work bench. My first attempt wasn’t satisfactory:

So, I ended up going with something a little more appropriate for aircraft work……the center section that comes in the wing kit 🙂

This thing worked out pretty great.  It’s heavy enough to hold the aileron flat, but not to heavy to damage, and its almost the length of the entire aileron.  I also cleceod every hole where a CS4-4 bling rivet would go to help hold it straight.  Next I used my rivet squeezer to squeeze the rivets on the bottom of the trailing edge skin, to attach to the nose rib.  Then moved on to squeezing the bottom rivets to the end ribs. That only leaves the blind rivets left.  I removed every other cleco, and staged a few CS4-4 blind rivets in the holes.

The first thing to rivet was the counterbalance pipe, and with the new tool, it was easy. I then started in the middle of the bottom skin rivets and then worked my way out from the center to the ends of the aileron, using the new pneumatic rivet puller to do the work.  After a little adjusting, the rivet puller was working really well, and setting the rivets, and snapping the stems in one shot.  Like the instructions mentions, every few rivets I would double check that the aileron is still laying flat. The CS4-4 blind rivets sit pretty nicely into their dimples:

I did have one mess up I had to correct. During squeezing one of the rivets, I let the squeezer bounce a little and it set the rivet a bit proud of the surface.  Too proud actually.  I ended up drilling it out, and re-riveting it.  Here’s the ugly bugger:

After a couple hours, I eventually wound up with a fully riveted left aileron! I decided to leave the mounting brackets off for now, since these were going on the shelf for a while.  I didn’t want the protruding brackets to ding or dent other parts of the aircraft as they sit on the shelf.  I will put them on once I get ready to mount the ailerons. Here’s me, holding the aileron:

Here’s all the photos from todays work:

Google Photos Link:

Hours Worked: 2.5

Riveting the Left Aileron

Time to start riveting up the ailerons! I gathered up the parts for the left aileron and studied over the drawings and instructions, and began final assembly and riveting on this guy.  We start out by riveting the A-704 nose ribs to the A-409 counterbalance pipe, and then slipping this assembly into the leading edge skin and cleocing it in place.

Once the assembly is in the leading edge, we go ahead and cleco on the spar, and then rivet the nose ribs to the spar, only.  This is because the rivets are hard to get to when the trailing skin attached. I put the shop heads on the rib side of the spar, because the metal is thinner there.

Once the nose ribs are riveted to the spar, we go ahead and slip the trailing edge skin under the leading edge skin and cleco it to the spar. This took a little fiddling around, and in between the process of taking photos and fitting the skin, I went ahead and removed the blue plastic, since it was getting close to time to rivet.

I also got a little creative. I had seen a few builders make a quick little holding jig for the aileron so you can attach it firmly to the bench, which makes it MUCH easier to rivet.  It’s as simple as cutting 6″ lengths of 2×4 and screwing them down to your bench.  I then took some spare brass fittings and some drywall screws to make fasteners for the aileron, and screwed it down to the 2×4’s using the mounting bracket holes in the spar.

The photo below shows how I used some scrap brass plumbing fittings to serve as “soft bushings” to keep the drywall screws from damaging my spar. They also help to distribute the light load more evenly.  These are only just tight enough to keep the aileron from wiggling about while I am riveting on it.

This made it SOOO much easier to rivet.  Vans has us rivet the TOP of the skins to the spar first, using the opening between the skins on the bottom as easier access. Essentially, my aileron is held upright so I can reach around with my left hand and hold the bucking bar inside the skin (reaching in from the unfastened bottom of the skins), and shoot the rivet on the top of the spar.  After a little bit, I eventually had the top riveted and looking good.

Next was to rivet the nose ribs to the leading edge skin, but ONLY the top half of the skin gets riveted for now.  Leaving the bottom loose to make access easier.  I used my squeezer to set these rivets extra carefully since they are on some complex curves. There is one odd ball rivet that is a tad longer than the other AN426AD3-3.5, its an AN426AD3-4, and the plans marks where it goes….right in the corner where the rib mets the spar and skins.  After the nose ribs were halfway done, we move on to inserting the end ribs and riveting ONLY the top half of those guys on each end.  Again, i was able to use my squeezer to get nicely set rivets here. Vans also has us go ahead and rivet the end ribs to the spar with their flush rivets.  The other holes are the bolt holes for the mounts.

Having successfully riveted the top half of the aileron, I decided to call it quits for the night.  Harbor Freight is having an Easter sale tomorrow, and I think I will pick up a cheap pneumatic riveter to set all those blind rivets on the bottom of the aileron.  This is a good point to stop, because I can’t do much more until I get that blind riveter. Here’s all the photos from tonights work:

Google Photos Link:

Hours Worked: 3.5