Wings 81 Total 544 - fluting and straightening Fuel Tank Ribs

Howdy followers. Been absent for a couple of days. Work, extreme hot temps, and smoke from massive fires here on the front range of Colorado have taken their toll on me this week. I managed to get out for a bit to start straightening adn fluting a couple of the tank ribs. When I first started, these ribs appeared to be so far out from "straight" that even I was questioning if I would be able to straighten them out.

Then I started the same process as I have done for all the other ribs - flute first, check rivet hole alignment on both flanges with a straight edge, then straighten the edges with the flange tool and the rubber hammer method.

Here is the rib after all the straightening and fluting is done.

The hardest part about this is dealing with the optical illusion that you still have a large curve in the nose section, even after you know that it all lays down relatively flat on the bench. This happens because the flanges around the nose that are cut into separate sections are also tapered down. It leaves you with the impression that the rib is curved. You may also noticed other sections of the flange further down that appear to be curved as well. this is where you have to remember that the goal of this exercise is to end up with a row of very straight rivet holes.You must focus on this as the goal since the holes have been prepunched.

If you were doing a full lay up where you would be marking all the hole locations then the goal changes just a bit. In that case you are trying to acheive a flat even web and flanges that are 90 degrees. While this is also the real end goal of the process for the ribs with the prepunched holes, you end up needing to focus more attention on hole alignment since the holes are already positioned on the flange. In the end the flanges still end up at 90 degrees to the web with the holes aligned. SO this is a testament to the CNC process that is used to prepunch and accurately pre=bend all of these parts adn still have then end up looking the way that they are supposed to, with everything in alignment. Simply amazing to me.

and finally a pic of the first pair of tank ribs all nice and straight and almost ready for some proseal! Always amazes me how nice they stack up after this process.

The holes in these ribs act as flow ports that will channel fuel in the fuel tank from one section to the next, from the outward sections back toward the inner sections closest to the fuselage. With full to half full tanks the fuel will move through both the middle and the lower ports. After the fuel depletes it will flow through the bottom port only during straight, level cruising flight. Complimentary beer in the background for some "scale!"

Gearing for Oshkosh now. Should be an awesome event if the weather cooperates. Tried to replace a bad cigarette ligher/aux power plug in my car last weekend. Took me over half a day to figure out that I wasn't even removing the right parts per instructions from my Chiltons manual. Had to resort to Youtube to find excellent home videos that showed the correct way to do it. At least Van's instructions for the aitplane are far above and beyond the crap that you get from the automobile world. For me - a car is just a away to get to the airport. I am definitely not shy in epressing my opinion about others who just love their cars to death. People like that have obviously never had the experience of being free as a bird and not having to hug mother earth all the time. They are truly missing out. But, the other way I look at it is that if the majority of folks are still stuck on the ground salivating over their precious cars, then that means there is more room for me to motor around in the skies above. So be it!

Ron has his engine hanging party for his RV-7 on Saturday. He is installing the same engine that I will more than likely install in my bird - an Aerosport Power Lycoming IO-375. I am so jealous, but at the same time looking so forward to seeing how this is done. One day I will be doing the same thing. I expect that Ron will be flying by this time next year, and so will Steve Riffe for that matter. I'll be knee deep in fuselage rivets and parts (hopefully).

Hopefully I will get finished with a few more ribs tomorrow.

Wings 80 Total 543 Deburred the Fuel Tank Ribs

Took some pics of the curved nose portion of the wing leading edge ribs, and also managed to debur the fuel tank ribs. While doing the fuel tank ribs I found one that had a partially punched hole, but it did not go all the way through. I also noted that the curvature on most of the tank ribs is rather extreme. It is going to be interesting to see how well these ribs are able to straighten out. I will be working on that and final deburring of the nooks and crannys in each rib over the weekend, and hopefully I can start scuffing and cleaning them as well.

Here are the delicate cutouts on the nose of each of the of the ribs:

I still need to debur the edges of these small cutouts and some of small tooling holes in the rib webs before they will all be truly deburred. I will fit a small piece of aluminum oxide sand paper (Available at Napa stores that carry their painting supplies) in between each of the cutouts to smooth each of the edges. I find it interesting that when you compare Van's rib design to something like the Sonex, you see that the Sonex does not bother with the creation of the cutouts on the tip of each not rib. Part of the reason for this is that I think you have to actually form each of the ribs for the Sonex, so they don't have you create the support structure for the tip of their ribs, which remains open. So I like the idea of extra support at the tip of each rib, but wonder if it is necessary to suppor the wing structure.

The reason I am so interested in this is that when the time comes to fit these ribs inside the wing skins, my experience with the horizontal and vertical stabilizors tells me that if there will be any problems at all, it will be these cutout flanges on the nose that may get caught or hung up on the skin or a rivet hole or something. In the case of the fuel tank ribs, this might cause problems with the fuel tank sealant being able to properly seat between the parts for a good seal. So a smooth round surface that nicealy conforms to the shape of the skins is what is needed here.

Wings 79, Total 542 - Working on the Leading Edge Ribs

So it has been a few days since my last post - home projects, super hot weather, and work getting in the way a bit this week. Still, I managed to finish deburring, fluting, and straightening the flanges of the leading edge wing ribs.

On another note, I took a couple of pics from my camera phone the other day of the EAA B-17 Aluminum Overcast. They managed to get the new control surfaces installed, inspected, and test flown early last week and it was flying folks around town all weekend. Flew within a half mile of my house several times. The thing that gets me the most everytime is that there is absolutely no mistaking the sound of the wright-cyclone engines purring away as the plane lumbers through the sky. I could even hear it way off in the distance. There is also no other airplane with that distinctive look in the air, with its huge curved tail sticking way above the fuselage. True beauty in the air in my opinion. I find it hard to imagine that this was built as a war bird.

Anyway, here are some pics of the leading edge ribs. There are 6 on each wing. 2 of the ribs are positioned about mid wing where the joint between the fuel tank rib and the leading edge rib of the wing are basically side by side. The two LE ribs on the ends have no holes predrilled in the flanges, so I am not going to flute or straighten these until the time comes to fit them together with the fuel tank. Holes will be drilled for nut plates that will secure a strip of aluminum in between the inboard LE rib and the outboard fuel tank rib, as well as the skins that fit over both of these ribs, and until I know where the holes will be located I cannot flute the flanges yet.

And here is a pic with the two LE end ribs without the holes in the flanges sitting on top of the other ribs. I will finish these up later.

Some interesting notes about deburring and fluting these ribs. Deburring using the scotch brite wheel was not too bacd, but you have to be careful when deburring the many cutouts that form the very tip of the leading eade of each rib. The instructions also warn you to make sure that you remove an bumps in between adn around these cutouts to ensure that the skins will fit properly. I had to smooth over a couple of the separations by making several passes with the wheel until I was satisfied that the nose of each rib was rounded and smooth. So the deburring was not so bad, and that went fairly quick. Fluting, on the other hand was a bit more challenging that on the main ribs. The curved surfaces of the nose rib required several more flutes, and I had to go back and reflute a few times after I had straightened the flanges.

Straightening the flanges presented some additional challenges. The instructions say to use a hand seamer, and I can see where in some places this may be preferable to even using my handy dandy flange straightening tool the reason is that there a many rib hole stiffener flanges and impressions that tend to interfere with the straightening tool, not to mention that the straight edge of the tool is not conducive to curved flange areas such as the nose portion of each rib. Neither is a hand seamer for that matter. SO, I ended up using the tool where I thought I could to straighten most of the flanges, and then used a small rubber mallet - the one that comes with 2 tips that you find at most hardware stores. One side is a red-eraser-like rubber, and the other side has a plastic tip.

Use the rubber side of the hammer, laying it flat on the bench surface. Place your finger up against the inside edge of each flange to act as a kind of soft support block for the flange, and swing the mallet against the flange lightly until you start to feel the metal give a little bit. Then check it with a straight edge and adjust as necessary. Once you have practiced this a few times you will start to get a feel for when the metal is bending, as well as when it "feels" that it is straight. be careful on the nose sections of each rib when doing this procedure. They are very small and it is very easy to over bend them if you are not careful. A couple of light wacks with the mallet is all it takes to straighten this area of each nose rib.

Once I was done straightening the flanges, I rechecked the holes in each flange for proper alignment, and re-fluted or added new flutes and re-straightened again as necessary. Again, quality time spent here makes all the difference for ending up with a well fitting LE rib-to-skin assembly. If there are any questions about this then I simply refer you to the EAA Hints for Homebuilders video section on their website. That is where I learned how to use the mallet technique - on one of the 6 episodes of rib forming videos.

Now I just have the fuel tank ribs and some minor deburring to do on the rest of the ribs and I will be ready to scuff, clean, and prime them all. The funny part is that I think Ron Duren was also chasing this same activity during a similar time frame a couple of years ago, ebcause I remember reading his post about trying to get it all done before going tp Oshkosh. I am in the same boat right now. Funny how that works.

Wings 76 Total 539 All Main Ribs Fluted and Straightened

Finally got all the main ribs fluted and straightened tonight. Amazing what some good tunes on the radio will inspire you to do. Now I get to wash, rinse, and repeat for the nose ribs. I have not finished deburring the edges on the nose rib flanges so I will need to start there. Feels good to get the main ribs done, but there is still so much prep work left to do that it still feels like a small accomplishment at this point..

Here are a few more pics with all of the main ribs stacked up nice and neat:

Wings 74, Total 537 - WIng RIb Prep Progress

Slow but steady over the past couple of days. I still ahve about 12 main ribs and all of the nose ribs left to go, so at least several more days before they will be done. A good goal at this point would be finished by the end of the weekend, but I may be knee deep in the nose ribs in reality. Either way, progress is progress.

I am probaby spending way too much time checking rivet hole alignment, especially for the main ribs, since those can be flexed a bit to get them into position. The nos ribs, however, will need to be as spot on as possible to ensure that the curved leading edge skins and fuel tank skins will fit correctly from te beginning. I ahve already had the "pleasure" (NOT) of trying to move a nose rib while it is being tightly hugged by the skin - not fun, and very risky as well. Anyway - they are my ribs so I will work them however I want.

I only have one pic for you tonight, but I like this one quite a bit. It conjurs up memories of when I first started unpacking the crates that the Wing kit came in from the factory. They were all taped together, and when you severed the tape they almost sprang to the ceiling adn scattered all orver because they were so springy. This was partially due to how tightly they were mashed down and the way that they were stacked, but the main reason was due to how much curve or spring was in each rib after it came out of the forming blocks. I believe that all of the ribs in an RV kit are hydro-formed, which means they are placed under tremendous hydraulic pressure to for each rib.

SO this shot shows the stack of remaining main ribs in the background, and a stack of some of the completed ribs in the foreground. Notice the nicely flat and neatly stacked completed ribs in the foreground, compared to the curved and messy looking stack in the background. What a difference a little fluting and flange straightening can make!

Each stack of nice looking ribs is one pair, one for the left and one for the right. So there are 10 ribs in that completed stack. I am pleased with my progress thus far, slow as it may be. I would guess that on average I am spending about 10-15 minutes on each rib. Time well spent in my opinion.

On a parting note, if you are building one of these, and you want to have some fun with those that are a little on the "unkowing" side when it comes to airplanes, just take some of the unworked ribs and cleco them to the main spar and start boasting about how great they look. Then sit back and watch the curious looks and listen to the comments that you get. My idea if fun I guess. Of course, don't do that to anyone you expect you might take up flying someday - as they may have a change of heart if you play that joke on them.

Wings 70, Total 533 - Fluting and straightening rib flanges

Rib work continues. Here is a shot of one of the many main ribs already fluted, with fluting pliers to one side. I managed to finish deburring all the main ribs - well, mostly anyway. Small cutouts for joggled flanges will need to be sanded down by hand, but the main parts of each flange are done. I ran each of them twice across the scotch brite wheel on the grinder, angled from the outside and again from the inside. I have found that this seems to adequately debur both sides of the edge of the flange, whereas if you only run the edge across the wheel from one side, it still leaves some roughness on the other side of the edge. I also deburred each of the corner cutouts on the wheel, but more about that later.

All ribs come out of the forming blocks with a pronounced curve or warp across the web. It's a metal thing, and it's just the way that it is. Every rib has to undergo the process of fluting and straightening of the flanges to ensure that the prepunched holes will line up with the same holes in the skins.

To do this somewhat methodically, I did the following;

1. Must have a flat surface on the bench large enough for the rib
2. Lay the rib on the bench with the curve facing up. (flanges will also be facing up)
3. Look at the rib from the side, and note the hight point of the warp on one side
4. Take the fluting pliers and flute the high point until the rib flange sits flat on the bench. A good review of the hints for home builders video on the EAA web site will help you understand what needs to be done, but the methods in that video and the ones I am using are a tad different (mine are easier).  I think it is the Making Ribs video part 4 or 5 in the sheet metal category). The interesting part of this video is a question of what you should do first - straighten the flanges or flute the ribs.

In the end you may need to keep doing a little of both until they are just right. I chose to begin by fluting the ribs to align the rivet holes on the flanges as much as possible, and then straighten the flanges using the homemade flange bending tool that I made. Take the time and make the tool - you will be glad you did. Details are on VAF and also in my empennage posts - search the blog under Building Tips and Tricks. Attending the EAA Sport Air Sheet Metal class will also give you experience with this.

Anyway, keep fluting the high points of the warp until it seems that the flange and web are sitting square on the bench. Then do the other side of the rib the same way. The ends of each rib are straight bends, and are not curved that the top and bottoms of the rib, so these flanges will NOT require any fluting - only some straightening when the time comes.

5. Now set the rib on one of the flanges, with the other facing upward. Take a straight edge (my 24 inch thin metal ruler from Cleaveland tools works great for this) and align one end woth the edge of the outermost rivet hole on one end of the rib, and then align the other end of the straight edge with the hole on the opposite end of the flange. Now look at the alignment of the holes along the rest of the flange. Chances are that not all of the holes will align along the straight edge exactly the same as the two outermost rivet holes. This means that a bit more fluting is necessary.

6. When finished fluting, use the flange straightening tool to straighten each of the rib flanges, then recheck the holes again to ensure they are still aligned. If they are not, then repeat the fluting process, adding new ones if necessary, or deepening or reducing existing flutes as needed.

Time for some more pics to illustrate:
The warp:

They can also be a bit twisted from front to back as shown in the next pic:

Next is fluting the highpoints of the warp. DO NOT fall under the spell that you must flute the gap between every single rivet hole on the flange. Most of the time you only need to create a few flutes to completely straighten the the web of each rib. So far I seem to be averaging about 4 or 5 flutes per flange on the Wing ribs. Remember to place the pliers half way between the rivet holes, and NOT insert the fluting pliers until they bottom out at the bend of the flange. Keep the pliers about half way out from the bend to maximize the effect of the flute. Fluting is skill that must be practiced. The more you do it, the better you get. There are tricks to knowing just how much pressure to apply to each flute, and where to place them - and you will learn these tricks by practicing the art.

And after the flute is applied. The shadow makes it seem that the bow is still there, and it is, but not as much as it was before the flute was applied.

Think you are done with fluting?- think again. Looks pretty good though.... Notice that the flanges are still not 90 degrees to the rib web (boughed outward just a bit.)

After you think you have the flanges all straight, check the alignment of the rivet holes:

Now for the fun part. Some of the holes may dissappear under the straight edge, while others may have a noticeable gap between the straight edge and the rivet hole, as shown in the above two pics. An easy way to figure out how to resolve these alignment problems is to remember the following:

Holes that vanish under the straight edge require more fluting, while holes that are gapped require less fluting. Of course this all depends on which side of the hole you are holding the straight edge. What becomes difficult is determining the exact amount of pressure to apply to each flute so that the flanges come out perfectly straight. Another problem that I tend to have is that after I have verified that the hole alignment is as perfect as it can be, I experience an optical illusion that tells my brain that the flanges are over bent, but the hole alignment does not lie, as long as your straight edge is really straight of course, and that is what you need to focus on.

Once the flanges are straight, the rib should also sit flat on the bench. There may be a small amount of offset, but that is usually due to twist in the rib, which you can correct by applying torque in the opposite direction of the twist. They don't have to be absolutely perfect, but the more aligned each rib is, the easier it will attach to the wing skins.

Now on to the deburring pics. First is an example of running the flange edges across the scotch brite wheel:

Next is deburring the notch on the trailing edge corners of each rib:

And next is the cutouts on the leading edges of each rib:

I only wish that I had a grinder that had an extended shaft to provide extra clearance from the grinder motor, but you learn to make due with the tools that you have, so you adapt and overcome.

Then lastly is the flange straightening. Keep in mind that I posted some pics a bit out of process order. May fix that later but not right now. Just remember to debur, flute, and straighten - that seems to be the order that works best for me.

If you take a straight edge (angle edge or triangle is best for this step) and check each rib flange, you will most likely find out that they are not set to 90 degree angles to the rib flanges. For the RV-8, all rib flanges on the wing ribs are supposed to be 90 degrees to the rib web, and will need to be straightened. Notice the gap in the next pic:

In comes the straightening tool

One of the challenges of using the tool on the wing ribs is the slight interference of each of the stiffening holes. I decided to basically ignore them and applied pressure to the flange as necessary. There was no damage to any of the lightening hole flanges/stiffeners - they just spring right back into action as if nothing ever happened.

And the rib flange is now square after being straightened with the tool - works like a charm. Remember, the bending brake angle is 11 degrees over 90. This seems to provide the right amount of bend with the amount of spring back due to the thickness and tension of the metal kept in mind. Alot of this also has to do with where you hold the handle as you apply the pressure to the flange, and how much pressure to apply. It is possible to over bend the metal slightly if you apply too much pressure. Again, practice makes perfect here.

I do try to avoid the areas where I have added flutes to each flange. Use the straightening tool just on one side of the flute or the other, slide the flange down, and apply pressure again. you can make a bigger one with a 2x4 but I have found that I like the control and the ability to straighten smaller areas using the 2x2 on my tool as shown:

Still a bunch of ribs to do - this will probably take me at least the rest of this week in my spare time to get all the ribs done. Then I get to scuff and clean and prime each one..... If I am lucky I will be riveting the ribs to the main spar just before I leave for Oshkosh 2012.

Tail Wheel Endorsement and Aluminum Overcast Visit

One of the things you are ocassionally reminded about during the build is the fact that you just can't stop flying all together while you are building and expect to be able to hop into your new RV aircraft and head for the skies. I have posted about this at various times in the past, and it bares repeating here. An RV is a hot rod high performance aircraft, regardless of how that is defined per the Federal Aviation Regulations (FARs). I am constantly amazed by the folks that seem to think that just because you ahve the money and the time, that you will be ready for what is in store when the day finally comes to step into the cockpit and fly it. The most surprising one I encounter are individuals that either do not even have their pilot certificate yet, or low time private pilots with absolutely no experience or flight time in aircraft that are considered complex or high performance, or simply contain advanced flight and avionics systems.
The bottom line is that all of the RV line of aircraft fly very fast, and they are very hard to slow down, and in that respect their flight characteristics are very similar to a Mooney. I was fortunate enough to fly in a Mooney M20J during my commercial instrument training in college, and I have also experienced a multitude of other aircraft that have given me an appreciation for the term "high performance."

Anyway, the bottom line is that whatever you do, you cannot stop flying while you are building, so you have to find a balance. As such, I have decided that now is the time for me to pursue my tail wheel endorsement. I made this decision just about the same time that 2 days worth of absolutely severe weather hit the Denver area, with unGodly amounts if hail, wind, and tornadic activity, all taking their toll across the entire metro area.

I decided to join a local flying club at Centennial Airport, one that I had actually been a member and instructed at many years ago. Aspen Flying Club currently has a Citabria for rent, and I decided to take advantage of that. The bad news is that I always wanted to join to get access to several other Cessna and Piper aircraft, but as it turns out the airport got hit heavily by the hail, and several of the club aircraft, which are all tied down on the ramp, got damaged by the hail. The good news - the Citabria was under a covered parking area and did not get damaged. SO I am in luck as far as tail wheel training is concerned, and I am very happy about that.

Why am I doing this? Well, I am still at a point in the build where I can remain undecided about building a nose wheel or tail dragger airplane, which is an option for most the Vans RV aircraft designs. I do not ahve to commit to this until I am ready to order the fuselage kit. The main reason is that the landing gear location and design is different between the two types of aircraft, so once you start working on the fuselage you have to know which one you want.

I am using the tail wheel endorsement to help me decide which way I want to go. Here are some of the pluses and minuses of going either way:

Tailwheel

Pluses
Cool factor - looks neater and more nostalgic, especially if building a WWII look alike like me.
Clearance of the prop tips from the ground is exceptional = opens up landing at grass or other soft fields.
Allows different sizes and choices of prop and engine - moreso that nosewheel airplane.
Better ground handling
Easier to enter/exit the cabin and aircraft (No additional foot step weldment required)
More difficult to inspect under the wing at critical flight control attach points

Minuses
Requires constant stick and rudder skills to keep from groundlooping during landing
Forward visibility during initial takeoff and finl landing phase is almost nil
Difficult to tie the tail down securely
Nose over and flip over potential if breaking too hard or a brake locks up
Harder to take off and land in cross wind conditions
May be more difficult to start due to angular differences of fuel tanks, gravity working against you, and more dependence on fuel pumps working correctly.

Nose Wheel
Pluses
Forward visibility always during take off and landing
Better cross wind handling on take off and and landing due to shorter moment between center of gravity/lift and the location of the nose wheel compared to same with a tail wheel (longer moment)
Fuel tanks level - easier starting at all fuel levels in the tank
Forward CG forces nose to come down onto nose gear and angle of attack of wing to reduce, aiding in landing stability (tail wheel down forces the wing to go to a positive angle of attack).
Shorter moment of nose wheel results in less sensative steering control (can also be a minus)

Minuses
Less cool factor than for a taildragger RV, but in my opinion it will look cool either way
Harder to enter/exit the cabin. Big drop off the back wing, and must only load one person at a time or airplane tail will strike the ground hard.
Prop is much closer to the ground - limits prop sizes and choices, and potential for prop strike is increased.
Vans nose wheel design on their "A" model aircraft has been under some scrutiny, and is considered a weak point in their design by some. This is due to a number of accidents that appear to have involved a nosewheel collapse to one degree or another.

My personal thoughts on this go back to my opening paragraphs about level of skill and ability. Throughout my flight instructing career, I have yet find a private pilot with the takeoff and landing skill and precision experienced by those that continue their training for a commercial pilot certificate. Therefore, private pilots without the benefit of this additional level of skill and training are much more prone to performing bad landings where the nose gear can experience a large degree of punishment. I think that many of these nose gear failure incidents in RV airplanes can be at least partially, if not entirely attributed to improper landing technique by the pilot. Proper take off and landing technique should significantly reduce, if not entirely eliminate all nose gear failure episodes in RV airplanes IMHO.

So, I signed up at the club today, and it also turns out that the EAA-owned B-17 Flying Fortress, Aluminum Overcast, is in town this week to support the Rocky Mountain Aerospace Museum. Unfortunately, the folks on the ground really messed this one up as well, and did not put the aircraft in a hangar when the hail arrived either. The B-17 has cloth aileron, elevator, and rudder surfaces, and they were all damaged beyond reasonable repair. The aluminum skins were also damaged, but not nearly to the extent of the control surfaces. Here are some pics of the damage:

And I thought my ailerons were big - holy cow!

And here is the aluminum skin damage all over the airplane

Now if you are like me, this is just nothing less than very sad to see. Why did they leave it outside? As far as I am concerned, screw the business jets and protect the heritage of our past to the Nth degree. These eloquent pieces of machinery protected and served our country jsut as much as the service men and women did, and they deserve just as much care and attention again IMHO. Truly ashame that this happened, adn if this was due to decision or lack of decisions made by our own local FBOs, then shame on them.

Now, having said all that, the good news is that EAA knows how to ahndle these situations, and much to my surprise, when I arrived, I learned that EAAD had already transported two new ailerons and two new elevators all they way from Oshkosh to Denver by ground transport shown below, and they had already removed the damaged ones adn mounted the new ones in place. Truly spectacular!

Nice to see my annual EAA dues put to good use. SO the word is that they will have to finish installing some spacers and hardware and reconnect everything, get it inspected, and they expect to have this all done in time for flights to be conducted by next weekend. Ground tours are still being conducted, adn the min event is open to the public through tomorrow at Signature FLight Services Hangar on the south side of the airport. You can fly the B-17 on MS flight simulator (I crashed the first couple of times but eventually got the hang of it - very cool). Hangar Dance is this evening - wish I had someone to go with. SO the airplane will be here through next weekend - if you are local you should definitely come out and see it - maybe even sign up for a ride. There is much more to see and do, especially for the kids.

Here is a picture show of some of the other attractions:

I really like this next one. Don't forget to click on each of the pics to get a larger resolution image with much better detail. :)

As a final thought, at one point I was just standing under the nose of the B-17, when I noticed something odd. On the bottom of the clear nose cone, sitting in what appeared to be a puddle of water, I found a rubber ducky just sitting there looking, well, ducky I guess. Never expected to see that. Right at that same moment, a gentleman by the name of Mike Niles from Bomber group 490 that flew as a bombradier during WWII in the B-17, asked me if I knew anything about the Norden bombsight. (He thought I was staring at the bomb site, and I did not have the heart to tell him that I was staring at a rubber ducky sandwiched in between the plexiglass and the frame of the airplane.

 Can you see the duck?

Anyway, as I have written in previous posts about similar encounters I have had when speaking with several other veterans, I became absolutely fascinated by all ythe stories he was telling me. But before he started on those, he told me that the bomb sight that is installed on aluminum overcast is pretty close to the actual real thing. He explained how the course correction and other sight alignment knobs worked, adn explained to me in detail how the ahnd off between the pilot and bombradier was performed in preparation for and during the bomb run. Absolutely fascinating. We must have spoken for about 25 minutes before e begged off saying "I am sure I ahve bored you to death already," to which I replied - "Absolutely not!It is the details about how some of this was done that I have always yearned for, and evey opportunity I get to speak with someone that is willing to tell the stories and divulge some of that detail is what I long for." Then I thanked him for service, shook his hand, and we parted ways. As I walked away I could not help but get the same feeling that I have had many times before during similar moments, that this was probably the first and the last time I would ever get to speak with this gentleman, and how truly blessed I am for having had the opportunity to do so. God bless our servicemen and women.

I will divulge more of the stories from Mr. Niles in future posts, as they are quite fascinating. This one has become long enough that I should probably close for now and go get some dinner. More rib work scheduled for this evening hopefully.

Wings 68.5, Total 531.5 - Deburring and Fluting Wing Ribs

Well last night it became obvious that I have not had to straighten or flute any ribs lately. WIng ribs turned out to be a little bit different than the empennage ribs in that they are alittle less rigid and susceptable to getting bent incorrectly if you are not careful with them. I almost ruined the first rib I was trying to striaghten and flute.

After I figured out the process I needed to follow, it seems to be working out OK, but is taking a very long time for me to get the rib flanges to the point where all of the rivet holes line up fairly straight. I decided to use my 24 inch straight ruler as a straight edge to determine when the rivet holes in each rib flange are lined up correctly. Although I am using the straight edge to check for this, it is still a bit of an art to determine where and how much to flute each rib flange to get everything lined up correctly.

I have to try to find a way to do this a bit faster, but unfortunatey I think that this will only happen by repeating the process on each rib until I find the magic formula to straighten each one in the least amount of flutes possible.

The process is basically to lay each rib flat on my bench, then determine where the deepest point of warpage is located, and flute that part of each flange. Then I lay my long ruler on top of the flange with the straight edge right next to the two farthest rivet holes, and check the remaining holes to see if they are outside the line or inside the line made by the ruler. For the empennage ribs I was using a piece of fishing line with some success, but the ruler seems to work better on tge larger wing ribs.

Noting the position of the rivet holes against the straight edge of the ruler allows you to determine where and how much to flute each rib. ANother part of the process is to then place each rib in my homemade flange straightening tool, adn straighten each of the flanges. You may have to straighten, then flute, then straighten adn flute some more until it all ends up correctly. Each flange should be 90 degrees to the rib web so that the wing skins will sit on top of each rib correctly, and all of the rivet holes need to line up correctly to match the prepunched holes in each wing skin.

So this continues to be a time consuming process, but it is not overly difficult to do. I'll have some pics tomorrow to better illustrate some of the challenges of this.

Wings 67.5, Total 530.5 - Deburring the Wing Ribs

Had to take care of home repair projects over the weekend, so I was not able to get back to the build until now. The lawn mower and the dryer both decided to bite the dust at about the same time. Spent all day Saturday on the lawn mower, and the dryer is still pending... And so it goes.....

Tonight I managed to start the rib deburring process. First step was to debur the inside edges of all the lightening holes. My tool kit from Cleaveland tools included two different miniature Scotch Brite wheels mounted on a standard 1/4 inch drill shank. The plans mention that putting one of these in a drill will make the job quick and easy. My experience, however, is that the hand drills just don't turn the wheel fast enough for them to be totally effective. SO I mounted mine on my drill press as shown below:

Whne I started this process, the scotch brite wheel did not have any of the grooves in it. Next pic shows why the grooves appeared:

THis method worked out very well. Just run the edges around the turning scotch brite wheel. I did the major holes in the main ribs as well as all the tank and nose ribs. Only took about a half hour to do them all. I ran each edge around the wheel twice on one side of the rib, and that seemed to do a pretty good job deburring all the rough edges.

Here are the tank ribs with two smaller holes that also need to be deburred:

So am I done deburring ribs? Not by a long shot. Next comes all of the flange edges. The nose ribs will also require some hand deburring to get between all of the small separations around the curvature of the nose. This will probably take me several days to finish up all the edges, and then I will need to straighten and flute the flanges. This part has to be done extremely well to ensure that all of the holes in each rib will line up perfectly with the predrilled holes on the wing skins. The broken dryer actually makes a pretty good work shelf. Oh well, at least I got started tonight....