Securing the Left Wing in the Stand

Not much to report on tonights work.  I got the left wing completely secured in its stand and made sure the aft spar brackets were secure.  I started out by making sure the wing spar was level as possible and had no twist in it.  I still have a bit of sag towards the middle, that I need to figure something out on.  I will probably go the route of using bottle jacks like everyone else. Once I was happy I had it level, I drilled the mounting holes for the outboard main spar bracket.

And then bolted them to the horizontal support arm on my wing stand.  I used 1/4″ bolts for this, as I had plenty of them. Next up was to secure the aft rear spar on both the inboard and outboard sides.  After a bit of fiddling around with various parts and such, I decided to use aluminum angle and the existing 7/16″ tooling hole in the outboard rib and a couple of C clamps.

I didn’t get it in the photos, but I used a plumb bob to line up the all the outer most outboard holes in the main spar, outboard rib, and rear spar to make sure I had the mounting bracket holding the rear spar in the right position so all the holes would line up in a straight line.  Once I had that, I cinched the C-clamp down tight and moved on to the inboard side. I did something similar here, using some scrap angle aluminum, but I had to use a “spacer” by using a piece of 2×4 to get the angle to meet up with the rear spar doubler.

Using the same process with the plumb bob, I got it perfectly straight and then clamped it down. Finally, I clamped down the inboard side of the main spar to its horizontal support using C-clamps and a piece of plywood to help avoid damaging the expensive spar support bars.

I’ll move on the right wing stand and getting it to this point, while I decide what I am going to do to support the middle of the wing to prevent sagging.  That wraps it up for tonights session.   Here’s all the photos, including some closeups of the wing stand and its adjustments I made.

Google Photos Link:

Hours Worked: 1.75

Riveting the Left Wing Skeleton

It’s time to rivet up the skeleton so that I can mount the wings into their stands to finish up the work.  I was going to do the riveting in the stand, but it appears it would be easier to do if I laid the wing on the table and then riveted the ribs and the front/rear spars together before hanging on the wing stands.  Since I had already riveted on 11 of the 13 ribs to the main spar, I went ahead and riveted the remaining ribs to the main spar, and then cleco’d on the rear spar.  I did find out that those three nut plate holes down near the root on the spar web are indeed for the fuel tanks, and I have to back drill some Z-brackets using the holes. so I did not go rivet the nutplates on.  I will leave them off for now, and just try to work around the tight space with the ribs when the time comes.

I did manage to find some #10 nuts and bolts to use to hold my bracket for the wing stand, so I stuck those on using washers on both sides to prevent scratching and spread the clamping force.

I laid the wing back down (facing as if it would be mounted with the spars “UP” side facing “UP”) so I could cleco on the rear main spar. Once I had the rear spar clecoed on, I went down each rib and double checked which rivets I need to set now, and which holes I need to leave empty as the Flap and Aileron seal pieces attach using some of the holes where the ribs are attached. I used a sharpie to mark the holes I needed to leave open and cleco’d everything together.

Next up was to rivet the outboard end rib to the rear spar ONLY.  Since we have the aileron mounting bracket that goes on here in the future, we use flush mount rivets here.  I used the squeezer to set these rivets nice and flush.  I did have to dimple the rib as I have not done my dimpling yet….something I SHOULD have done before riveting the ribs on.  It’s not a big deal, I can still get them dimpled using the squeezer, but it would have been much faster and easier to use the DRDT-2. I’ll remember that on the right wing 🙂

Then I worked my way down the wing, squeezing the rivets for ribs to rear spar.  There were a few rivet size changes, so MAKE SURE you always double check what size rivet the plans call for.  We have doublers, reinforcement bars, etc, that all add varying thicknesses.  You can see where I marked the holes that need to be left open for the flap and aileron gap seals below:

The clecos are my empty holes that I skip for now. I used the squeezer to easily set all of the rivets for the rear spar. I took a good bit of time on this one because I was having to double check all the rivet sizes and such to be sure I used the correct ones.  Eventually I had the wing skeleton to the point I could stick it on the wing stand for a preliminary fitting.

Theres some sag towards the middle which is to be expected.  Van’s tells us that we should use a bottle jack or similar to help support the rear spar in the middle to eliminate the sag.  That wrapped up the session for tonight.  I’ve a few more tiny things to do before its bolted and clamped into the stand. Here’s all the photos from tonight:


Google Photos Link:

Hours Worked: 3.25

Prepping the Left Wing for the Stand

Since the left wing stand is anchored and ready for the wing, I decided to go ahead and get the left wing prepared to go on the stand to free up some space in the shop so I can work on the right wing stand.  The plans tells us we can cut a 5″ piece of angle and use on the outboard end rib on the wing to create a mounting tab for the wing, and even tells us its OK to use 3/16″ bolts and drill holes into the rib as it won’t compromise strength.  So, I cut some scrap angle aluminum down to 5″ and made the bracket flush with the spar web which worked out perfectly to hold the wing level on the stand while my wife Tammy helped hold it.

I just clamped the angle to the outboard rib to check that it was at the right height to hold the spar nice and level.  Once I was happy with the placement, I drilled two new holes into the angle and through the outboard spar sized to a 3/16″ hole.  You can see the new holes below.

Now that I have the bracket drilled and ready to be bolted, it’s time to go ahead and assemble the wing skeleton per the plans.  I gathered up all my ribs, and double checked their placement and clecoed them all to the wing. There are a few towards the wing root that have extra holes for the rear spar, so I made sure they lined by cleco’ing on the rear spar temporarily.

The DRDT-2 table worked good to help hold the spar from twisting with the weight of the rear spar.  I simply have the main spar clamped down to the bench to hold it up for riveting.  The alodining on the ribs, really match up nicely with the anodizing of the main spar.  I have decided to not prime the ribs, and just to leave them alodined.

Once I had verified all the ribs were in the proper place by double checking against the plans, and making sure it all assembled nicely, I labeled the station number on each rib for easier identification when I rivet.  I am way to “round” to fit in between the ribs to rivet, so I’ll have to remove several at a time as I move down from the outboard end to the wing root. As a side note, the plans tell us to NOT rivet the w-712 outboard rib to the main spar, and to ONLY rivet it to the rear spar.  This is because we need to also attach the nose rib to the main spar AND to the main outboard rib, essentially sandwhiching the main spar between the nose rib and main rib using the same rivet line.  So, I left it clecoed in place for now.

I started with the outboard, and worked my way inb0ard riveting the ribs as I went, double checking the rivet sizing as we change sizes (lengths) a few times due to the thickening spar web.  Thankfully I was able to flex the rib just enough to get the rivet gun and set to line up with the rivet and drive the AN470AD4-7 rivets.   They came out pretty good considering I haven’t done any riveting in about 7 months!

There are 14 total ribs, but I was only able to get 11 done.  The last three are pretty close together and there are three holes that look like nutplates go into.  I didn’t want to cramp up all the space to set any nutplates, so I decided to just call it a night for now, and I’ll look into the plans to see if these can be done now, before I cramp up the space with ribs.  I think they are for the fuel tank?  See the photo below.

And here’s a shot looking down the hole I am planning on using for the conduit.  All the ribs line up nice and neat, and you can see straight down the line!

And here is a shot of tonights work:

Thats it for tonight.  I’ll check the plans for those nutplates, and decide if I need to go ahead and set them now to make it easier.  Heres a link to the google Photos album:

And heres all the photos from tonight:

Hours Worked: 3.25

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!

Google Photos Link:

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