Right Wing Skeleton Assembly and Drilling

I managed to sneak in a couple hours of work this afternoon.  Tammy was getting Acacia ready to go to “Nanas” house so we could have a date night.  So, I figured I would try to get a little work done while she was dropping the baby off.  Tonight is pretty much a repeat of last night, except on the right wing.  I managed to complete this wing a little faster than last night since I was familiar with what to do.  It seems like this will be par for the course on building the wings: Learn from one side, and then you can do the other side a little faster/better.

I started out by clecoing all the ribs the right main spar, being sure I transposed the handed-ness of the ribs.  Van’s only gives us the left side view of the wings, so they leave it up to the builder to be smart enough to “transpose” the layout for the right side.  For example, a W-709-R (RIGHT handed inboard main rib) shown on the plans for the LEFT wing, actually would be a W-709-L (LEFT handed inboard main rib) for the RIGHT wing.  Once you look over the plans and see how it goes together, its actually not as hard as it seems (trying to read from a blog post and do the figuring in your head makes it…weird. heh.).

Once I had all the ribs cleco’d to the main spar, I clecoed on the rear spar, double checking its orientation.

Now, it was time to match drill the main ribs to both the main spar and rear spar.  That was simple enough, and didn’t take too much time.  The last thing left to do was to cleco on the leading edge ribs, again, double checking the orientation and proper handed-ness and then match drill them as well.

VOILA! I have another piece of kit that looks like a wing should look! I still haven’t fully decided on what to do for wiring, but I still have some time.  However, I think I may actually move on for now and start building the flaps and ailerons and leading edge skins.  Its currently winter time in Tennessee, so my workshop is hovering around 60 degrees, which can making working with ProSeal (for the fuel tanks) and bit challenging.  Spring and summer are only a few months away, so I will hold off on my fuel tanks until warmer weather.  I am also considering doing the same for the wing stands.  I think I would like to build the control surfaces while I have plenty of room in the shop. If I build the wing stands, I will loose a good bit of working area in the shop, so I will ask the experts on Vans Airforce if there are any gotchas to skipping ahead and building the control surfaces ahead of the stand and tanks.  At any rate, here is all the photos from todays build session:

Google Photos Link: https://photos.app.goo.gl/Bx5tJyDEThlWKNPu1

Hours Worked: 2.5

Left Wing Skeleton Assembly and Drilling

After completing all of the rib prep, I was finally ready to start doing the skeleton assembly and match drilling for the wings.  The plans tell us to be very cautious of not using tank ribs for leading edge ribs, so I made sure to sort out the two and set the tank ribs to the side.  Then, I took several minutes studying over the plans to make sure of the proper orientation of the ribs, and picked out the parts I’d need to complete one wing.  I figured I could get one wing completed tonight, and do the other tomorrow night.  I am a bit confined when it comes to work tables and space to build the two wings at the same time, at least until I build my wing stands.

I started with the left wing, since that is the wing that is depicted in Van’s plans.  This way I wouldn’t have to worry about transposing the plans for the other wing on my first attempt.  The instructions tell us that the ribs have a left and right handedness to them, and explains how to determine which is which.  The plans also denote the handedness of the ribs, so it was easy to match up.  I pulled the main spar from its storage and moved my workbenches around to give it good support.  Then I methodically picked the proper rib, double checking it against the plans before cleco’ing it into place.  Eventually I had all the inner ribs clecoed to the main spar, and a wing form was starting to show up a little:

Next up was to fit the rear spar to the skeleton so I moved my benches around a little more to accommodate it and clecoed the rear spar to the ribs, making sure I had the proper orientation. The wing box is starting to come into shape!

Now, it was time to attach the few leading edge ribs to the front of the main spar.  Again, I referenced the plans and made sure I had the proper part number in the proper orientation and then clecoed them onto the main spar.  Finally!!!! Its starting to look like I am building an airplane again! Its really rewarding to see the wing start to take shape after spending so much time on prepping the ribs.

The big empty space left on the main spar in the background is where the fuel tank will attach, and I won’t build it until a few more sections later in the plans.  For now, I match drilled all the holes in each of the ribs to their final size. Then I disassembled the wing, taking the time to number each “station” of the ribs so that I can fit the exact rib back in its original location.  This may be overkill, and not needed, but I figured I might as well go ahead and label each station just in case.  Once I had it all disassembled, I vacuumed up all the chips from the main spar, and set these ribs to the side for deburring at another time.

Now, I need to decide what to do about wiring looms/harness/conduits. The driving reason, is that I need to drill the holes for the wiring and any conduit that I plan on using now, before I prime these ribs for final assembly.  I am still leaning towards following the Vans approved rib drilling guide found here:  https://www.vansaircraft.com/pdf/Wing_Wiring.pdf and using the Vans conduit for the bulk of the lighting, strobes, heated pitot and stall warner wiring.  Then opening up the tooling holes as prescribed in that guide for the coax for NAV antennas.  I’ll put some thought to this over the coming days, and may even try to do a wiring schematic.  Thats it for tonights session.  About three hours total, and I have a fully assembled, drilled and ready left wing skeleton. Entire photo album is link below from tonights build:

Google Photos Link: https://photos.app.goo.gl/JqnmnU1zEfnZ2qR02

Hours Worked: 3

Leading Edge Rib Straightening and Fluting

4 months.  Thats how long it has been since I have done any major work on the RV-7.  Between work and family and then holidays, I really haven’t had much free time to get down to the shop and build.  Having some time off for the holidays, I decided to put work and learning aside for a few nights while I am off and get some work done on my build.  I only have a few ribs left to straighten and then flute, and they were the leading edge ribs.

These guys were a bit more tricky because of the curve on the leading edge, and I had to refactor my flange straightening tool so that it had a smaller “bite” to allow me to not mess up the very nice and sleek compound curve in the top of the leading edge.  You can see how much smaller the anvil is on my flange bender in this photo:

In the bottom left of that photo, you will see the new anvil I cut from some spare oak I had left over from the first, wider, anvil.  This worked great, and didn’t cause any warping or mis-shaping on the top curve.  I did all the rib straightening down in the shop on my bench, and then moved my stack of ribs upstairs so I could use my wifes granite counter tops as a perfectly flat surface to do my fluting to bring the ribs back into flat.

Heres my finished stack of leading edge ribs, with their perfectly 90 degree flanges, ready for fluting. Notice how much warping there is from the forming process.  This is why we flute the ribs:

And after about an hour and a half of fluting, I ended up with a nice flat stack of leading edge ribs.

Some needed a bit more than others, but they are much straighter and flatter now.  I might have to do a little more here and there once I start mounting them on the spars, but I’d say I was able to get them 99% of the way ready.  FINALLY I have all my ribs done.  All the flanges are at 90 degrees, and they are all fluted to be as true as possible.  This was probably the most boring work I have done so far, and I am SOO SOO glad I can move on to something else.  Heres all the photos from tonights session in one album:

Google Photos Link:  https://photos.app.goo.gl/0DF6VPiHYHkbKkjQ2

Hours Worked:  3.25

Wing Rib Fluting — Part 2

I found an hour or so to finish up the main wing rib fluting.  Like the last session, I used the table top method on our granite countertop and knocked out the remaining 14-something main wing ribs.  They stack much nicer now that they are all formed straight and with proper flanges.

I was going to start working on the leading edge ribs, but decided to hold off on those guys, because I think I will modify my flange straightener tool to work with these curved edges so I can more easily get the flanges to 90 degrees.  Then I can flute them all.  No photos from tonights work, as it is pretty much the same as the last session.

Hours Worked:1.25

Wing Rib Fluting — Part 1

About a week ago, I decided to bring my wing ribs upstairs and do the fluting up here, since that doesn’t produce any filings or shavings.  HOWEVER….I have had a lot going on family wise that I haven’t been able to spend much time on them.  I’ll also admit that over the last few days I have actually been fiddling with these things to the point of frustration.  I tried a few times to sit down and get the straight using the wood dining room table as my “flat surface”, and always end up frustrated because no matter what I tried, they never would come out straight.

You see, we have to flute  the flanges on the ribs because during the forming process they will get bowed a bit.  Fluting “shrinks” the metal down along the flange, pulling it back straight.  See how they are from the factory:

It seems like a simple process, and it actually is…..if your reference surface is truly flat.  😐  Turns out, our dining room table is not exactly flat, and I was using this bowed/curved surface as my guide and my ribs never came out right.  Once I realized this, thanks to my wife Tammy, I decided to use our granite counter tops, since I knew they’d be nice and flat.  After switching over to the stone counters, I ended up using the “table top” method of rib fluting.  This video shows how to do this method: https://www.youtube.com/watch?v=pIvFpVV6kIQ

The results speak for themselves.  After I did the table top method, with the flanges sticking up I flipped the rib over with the flanges down towards the counter top to double check.  Then I used a metal ruler to measure that the rivet holes were all in alignment.  Some ribs (like the one below) only needed a couple of flutes, while others needed many more.

I ended up getting the process down pat, and was able to knock out 14 ribs using the granite counter to and “table top” fluting method.  I did have to go back and re-do the ribs that I did on the dining room table, since they were not straight.  I’ve got a lot more to go, but I think this method will help me knock them out quickly. Here’s all the photos from tonight’s work:

Google Photos Link: https://goo.gl/photos/pc9q3jqyrzesHnzn9

Hours Worked: 2.75

Rib Flange Straightening — Part 1

Fighting off some sort of cold/sinus infection, I didn’t feel like putting in a whole bunch of work tonight, and I am still studying up for an Ansible exam but I did manage to knock out straightening the flanges on all of the wing ribs. All the ribs are pre-formed by Vans, but due to the punch and forming process, the flanges are not at a perfect 90 degrees to the the rib, so we need to bend them to a perfect 90.  The old way is to use a pair of hand seamers and do it all manually, checking with a square to get your bends perfect, but theres a better way.

A few months ago, while I was waiting on my wing kit to ship, I built a very neat little tool to help with this process.  I had seen several other builders make something similar, and they all raved about it, so I built one for myself.

It’s a pretty simple little tool. It’s made from a 2×4, a 1.5 x 1.5 piece of oak and some metal.  The anvil portion of the 2×4 (clamped down to my work bench) is angled at about 11 degrees, while the press handle is made from the 1.5×1.5 oak.  The 11 degree angle bends the flanges to slightly beyond 90 degrees, because the aluminum will flex back about 10 or so degrees, which leaves the flange at a perfect 90!  You can see how the rib sits in the tool here:

The 2×4 on the left serves as the “anvil” that the flange is formed against, and you can just make out the 11 degree angle on the face of the 2×4 (its tilting toward your right).  Also, notice how the handle portion (the oak 1.5x1x5 handle) also has a angle cut on the bottom.  This is a 22.5 degree cut I made on my mitre saw so that all the bumps and ridges in the rib would not get damaged.  They fit very nicely under this angled portion as you can see in that photo above.  Here is what it looks like without a rib in it:

To do the work, I just put the rib, flange facing upwards in the tool and apply pressure on the handle to bend the rib.  The result is a perfect 90 degree bend on the flanges! I can process an entire rib in about 20 seconds on this tool.  I’ll update this post with a video describing how to make the tool, and how to use it.  I think it cost me about $15 to make.  All in all, I was able to knock out all of the inner ribs for both wings in a little over an hour!

Google Photos Link: https://photos.app.goo.gl/RiI3OipxFfTQ4UKf2

Hours Worked:1.25

Wing Rib Deburring — Part 5 and DONE!

I wrapped up all the wing rib deburring tonight.  All that was left were the ribs for the fuel tanks, but like all the other leading edge ribs, they have all those little tiny flanges, and each one needs to be deburred.

I spent a little over an hour knocking the rest of these things out and then decided to do a little work on my flange straightening tool.  I had picked up a “edge rounder” routing bit so I could smooth the handle down a bit a few days ago, so I decided to move on to that for the rest of the evening.  I am not going to count those hours in the build log however, since I was pretty much just polishing up on the tool I made to help me get the rib flanges all at a 90 degree angle.  I’ll do that tomorrow and give details on it.

That (thankfully) wraps up all of the edge deburring for all of these ribs.  It took a lot of time, and wasn’t very fun but it had to be done.  I am just glad its over, so I can move on to some other task for a change! Here’s the stack of ribs I got done tonight.  16 total (I think that was the count):

Google Photos Link:  https://photos.app.goo.gl/vnPTL6Qy6oCavrcl1

Hours Worked:1.25

Wing Rib Deburring Part 4

One Hour…thats all I managed to work on the airplane tonight.  I’ve got a lot going on with work and family right now, so I don’t have as much spare time to get down to the airplane factory and build the RV-7.  Spending a lot of time learning up on Ansible and Satellite 6 as well as IdM (Three Red Hat products I deliver for our customers), and with Dad in the hospital recovering from surgery, I don’t find myself with any time left in the days.  But, any step forward is a good step, no matter how small.

Tonight, I simply finished up deburring 14 leading edge ribs, which includes all the little tabs and slots on the flanges.  Man, these things are a pain in the ass to do. It’s not so much difficult work, as it is tedious and boring and repetitive. It’s got to be done though!  I am still using emery cloth folded up to fit into the slots, and it seems to be working good enough.  I have about another 15 or 20 leading edge ribs left to do.

Here’s the aftermath of all that deburring:

I’ll probably just keep at it with the emery cloth.  one strip seems to last a pretty good while and they are cheap.  I’m not going to waste any more time and effort on trying to use a dremel or die grinder. Thats pretty much it for tonight.  These wing rib posts are always pretty boring and simple on just about every builders online log, and I can see why.

Google Photos Link: https://photos.app.goo.gl/dp5J5V1LqyJAbrTD2

Hours Worked:1

Wing Rib Deburring Part 3

After discussing the use of the scotchbrite cones with folks on the forums, I decided to go pick up some emery cloth and sandpaper to deburr the gaps in the rib flanges.  Making the cones, using them and making more was taking too much time. I only have the softer 1″ scotchbrite wheels, and it appears everyone is using the harder, grey looking ones.   After driving all over Chattanooga, I finally found some emery cloth at Tractor Supply.   I decided I would gently clamp the ribs down to my bench and then use strips of emery cloth like dental floss to get into the gaps of the flanges. I cut the emery cloth into about 3/4″ to 1/2″ strips that were just wide tall enough to fully cover the flanges, and that worked out pretty good.

I was able to get about 4 or 5 ribs using a strip of emery cloth and that was being conservative.  I probably could have gotten more, but this stuff is pretty cheap, and I can make about 4 strips or more from a sheet.  I was able to get the remaining 14 inboard and outboard ribs done using this method pretty quickly.  I decided to move on to the fuel tank ribs and knock them out as well.  Using the same method as above, they went pretty easily too, but I took extra caution to make sure the leading edges of these ribs were very smooth.  The plans tells us to make sure we also smooth out the bumps from the reliefs on the leading edge flanges because there are some complex curves here.  I started out using my bastard file to work the edges and bumps on the fuel tank ribs, but soon realized I could use my scotchbrite wheel on the bench grinder to make this easier.

And it did! Using the scotchbrite wheel, I put the grinder on the slowest speed it had, so I didn’t burn through the thin metal to quickly.  This worked out great! I could smooth down the leading edges very smoothly in no time using this method.  They were really smooth, and the skins should lay very nicely around this complex curve with no bumps or roughness.

I decided to carry on and go ahead and knock out all the leading edge smoothing on all the leading edge ribs using my scotchbrite wheel.  I was able to get them all done in about 20 minutes or so.  Now, I still need to smooth down gaps in the flanges for all the leading edge ribs, but I decided I’d leave that for tomorrows session.  I ended the night on a good note, and hopefully put a dent in the rib workload.  I’ll be glad when this part of the wing build is done! HAH!.  Here’s all the photos from tonight:

Google Photos Link: https://goo.gl/photos/2a8y2CEpbsAxcYJ17

Hours Worked:2.5

Wing Rib Deburring Part 2

After taking time away from building for a few days to spend some time with my family, I found a little time tonight to work on the ribs.  I am in the process of deburring all the ribs, and at the point of deburring all the little crevices and corners of them now.  In the last session, I cleaned up the lightening holes and edges.

I had read on the Vans Airforce Forums about a trick to help with deburring.  You take a small scothcbrite wheel, cut it into wedges and then use them on a dremel to get in all the small grooves of the ribs.  I tried this tonight, but not sure I am happy with how it worked.  I may have the wrong scotchbrite wheels for this.

I gave it a shot on my dremel, and the wheel just didn’t seem to do a good job of deburring, and took a lot of work it seemed.  I worked for about an hour or so, and only got about 6 ribs done.   The wedge would only last about 1 or 2 ribs before needing to be replaced, which took even more time to cut and shape into a cone.  It kind of sucked. After about an hour, I said screw it, and decided to ask a question on the forums about which wheels they were using for this before I waste any more time on trying this.  I called it quits for tonight.  I think I got about 6 ribs done, oh well.  Here’s the photos:

Google Photos Link: https://goo.gl/photos/Vz1KBqVCqNzYXekN8

Hours Worked:1