Right Wing 408 rib prep (Part 2) continues

Tonight I fluted and straightened the right wing 408 rib (second one). I also inspected the joiner plate that I already drilled with the first rib,and it seems to be in pretty decent shape as far as hole location is concerned, so at least I do not need to fabricate a new W-423 joiner strip. This means that I can follow the same process I did yesterday to set the new rib into position and correctly drill the rib flanges. I will place another order from Vans tomorrow for two more 408 ribs,one more .032 aluminum sheet, and about 6 feet worth of .025 aluminum sheet. Why do I need all that, you may ask? You'll see.

And progress comes to a screaching halt yet again!!!!! RE-doing the 408 ribs

First I have to rant - this post falls under my Vans sucks category so be prepared. After drilling all the holes in the joiner plate and 408 rib and the LE skin, I decided to remove the assemblies to see how well my holes turned out. I should have done more homework, because I think I hit upon one of the next great blunders in Van's building instructions that are just plain wrong, insufficient, etc. The joiner plates came out mostly OK. The ribs on the other hand are now scrap. The holes on the bottom flange all turned out OK, but the ones on the top, as I came to better understand after researching this a bit more, tend to wander inward as you drill, and therefore the rib flange holes turn out to be much too close to the rib web. There is a problem with the hole being too close to the rib web. Vans has stated that this can weaken the radius where the flange was bent and thus having holes too close to the web is not desired either.The other obvious problem is that you may never be able to get a good dimple for the holes. Here is pic that unfortunately demonstrates the demise of both the left wing and right wing 408 ribs:

So Vans sucks because once again they have failed to provide adequate instructions to help the builder ensure that the outcome of all the time spent on this part of the build can be completed with reasonable success. They tell you to position a completely hole-less rib,and a hole-less joiner plate strip sandwiched between the LE skin and wing spar.Neither the rear flange of the rib nor the skin flanges have any predrilled holes. Not only that, but this assembly is placed together in such away that it is almost completely impossible to clamp it all down correctly with everything exactly in the correct position.

Or so I thought anyway, until I stumbled upon several posts by fellow builders on VAF, the main one being this one:
Correct way to attach and drill 408 ribs and 423 joiner

I ended up using a combination of things from this post to address the problem and ensure a much more favorable outcome - no thanks to Vans - who should have done a much better job of explaining how to do this. This is yet another one of those coveted Vans blunders that forces you to have to order a new part-in this case new W408 ribs.

Step 1
So I have to order new 408 ribs, and if your joiner plate did not come out right then you need to order or fabricate new ones as well. I had already ordered two new 408 ribs so I just happened to have them on hand. I still need to order two more at 23 bucks a pop for my LE mod.

Step 2
Make certain that you mark the flute locations and flute the rib so that it is perfectly straight (or as straight as you can make it, since I have come to realize that NOTHING about metal airplane parts is perfectly straight - especially ribs)

Step 3
I decided to mark the minimum edge distance of the rear rib flange instead of trying to find the center line. Min edge distance for 1/8 inch rivets is 1/4 inch for the AN470AD4 rivets that are used to attach the ribs to the wing spar. Here is the line  and the method I used to draw it. This edge distance was taken from the outer edge of the flange, and not from the rib web. I did it this way because I wanted to know where the maximum outer location of each rib could be. The center of each rivet cannot be any closer than a quarter inch from the outer edge of the flange.

STEP 4
Next, use the following tools to securely fasten the rear of the rib to the wing spar
 - A Large square
- 3 bar clamps - one larger one to clamp the square to the wing spar, and the other two smaller ones to secure the rear flange of the rib to the wing spar. Clamp everything in place, being sure that the rear rib flange is flat against the wing spar web. The edge of the square is placed right up against both sides of the wing skin and along the edge of the wing spar flange, so make sure the edges of the wing skin are clecoed in all holes in this area.

You are clamping the rib to the square in the above pic - be gentle but firm,and check the rear flange through the inspection plate cover (left wing only) to make sure it remains flat against the wing spar web. While I apparently did not take any pics of this, go ahead and slip the old joiner plate in between the rib and the skin before you clamp the rib to the square.This will ensure that the rib is positioned correctly along the perpendicular axis of the wing spar. You won't be able to slip it in at the base because the square will be in the way, nor will it fit all the way in at the top because of this. All you are trying to do is account for the thicknesses of all the materials before you drill the rear rib flange holes. 

STEP 5
Start drilling the holes for the rear rib flange from underneath the wing spar web. Drill one hole and cleco, and check the rib flange to see if the location of the holes looks OK. The goal here is to drill all these holes in a straight line, which I sadly found not to be the case on my original right wing rib.

STEP 6
When done drilling all 5 holes, remove the rib and joiner,etc and inspect the location of the holes in the rear flange. They should be straight, and as the next pic shows they will also NOT align with the min edge distance line that was drawn earlier. I should note that I checked for this line through the holes before I started drilling with a mirror, and I could not see the marks then, which simply told me that the holes will be located somewhere other than at min edge distance. Here is where they actually ended up:

So they are just inside the min edge distance line that I drew, The holes appeared to be in a straight line, so the square technique worked, and they seem to be located on the flange well enough for the rivets to be set, so I am satisfied with this result.

Step 7
Now a reference line needs to be drawn on both the top and bottom rib flanges. The plan for all this is to re-use the drilled joiner plate since those holes are in position already, and use the line drawn on the rib flanges to align the rib through the existing holes in both the skin and the joiner plate. If you are drilling the joiner plate for the first time, then you should assemble all the parts thee best you can, trying to maintain that idiotic 11/16 inch extension of the plate from both the skin and the rib web. Then pre-drill the plate through the wing skin without drilling all the way through the rib. Then remove the joiner plate that you just spent all that time aligning, and finish drilling out the holes on a drill board. Actually, the nice thing about this is that you don't have to try to maintain the 11/16 inch extension. Instead, you should simply focus your attention on the ensuring that the holes in the joiner plate align with the line that was drawn per the plans. Center the line through the wing skin hole and then predrill each hole in the plate. At this point I don' t think it matters much if you do a few holes on one side and then a few on the other. If the half inch line was drawn correctly all you need to do is focus on the line through the wing skin hole.

Once you have final drilled the holes in the joiner plate, remove the rib as described above, and draw a reference line on the rib flanges that will show through both the skin holes and the joiner plate holes. To draw the reference line, you simply use a technique that I learned on Hints for home builders about fabricating a wing rib from scratch. You use your fingers and a set position of the sharpee pen in the desired location of the rib flange (usually the centerline of the flange as best you can eyeball it.) I used the same technique when I drew the line for the forward spar of the horizontal stabilizer. As you can see from the pic it worked pretty well, but the flutes got in the way and distorted it in a few areas.  I must have redone this line about 8 times before I was satisfied with it. I used acetone to remove the line and start over. Always run the line from the bent side of the flange,and never the open end, since that side may have slightly varying dimensions due to the hydro-forming process- especially when dealing with formed ribs.

STEP 8
With the rib flange lines drawn, insert the rib under the joiner plate and skin. Cleco the rear flange in place. Align the wing skin and joiner plate holes, and then slide the rib flange back and forth until the line appears in each hole. I found this to be rather easy to line up both holes and then position the rib flange using the mark. Again, you needn't concern your self so much with the 11/16th of an inch measurement, because as long as your lines are correctly in place through the holes everything should work out in the end. Here is what it should look like when everything lines up:

STEP 9
It is now time to start drilling. The best method is probably to follow the link to the VAF post I provided at the beginning of this post. Start at the flange holes at the rear of the rib, drilling a few of the holes with one hand while ensuring that the flange line marks are centered in the holes with the other hand. IF that first one goes in correctly the rest will be relatively easy to position through each remaining hole. After drilling a few holes at the rear, switch to the 3 holes toward the front or tip of the rib on the same side. Locate the line in the rib flange through those holes and drill them. Remember to put a cleco through every single hole that you drill.

Now switch to the other side of the rib. Note that out of all the holes that got messed up on mine, all the bottom flange holes were fine. It was only the topside holes that got messed up. So pay very close attention to the top flange holes and ensure that the line can be seen centered through each hole as best as possible. Follow the same routine to drill the same holes on the other side. Then switch back and forth between sides, drilling out a few more holes until you are done.

STEP 10
When all holes are drilled and clecoed, remove them, including the ones holding the rear rib flange to the wing spar. Remove the entire rib/joiner plate assembly, and inspect all hole locations in the rib flanges and the joiner plate and the wing skins to ensure they were not abnormally enlarged during the drilling. This time the holes came out much better aligned and in the location I expected them to be to ensure that edge distance and space for dimples was maintained:

NOw,why is this 11/16th of an inch thing so important? Well,simply put, there needs to be sufficient flange material to allow the drilling, dimpling and attachment of nut plates that will use a number 8 screw to attach the LE to the fuel tank. I checked the plans, which show a full sized drawing of the gap between the LE and fuel tank,and shows where the joiner plate and fuel tank ribs are located. There is supposed to be about a 1/16th of an inch gap between the joiner plate edge and the last fuel tank rib web, so exceeding the 11/16 length may cause interference with the fuel tank rib. On the other hand, too little material may cause problems setting the dimples for the nut plates correctly. Again, if all the reference lines in the joiner plate and rib were drawn and drilled correctly, I think this pretty much works out for itself. Your last step in this process is to check the joiner plate length against both the LE rib web and the LE skin edges. If you have roughly 11/16th of an inch on both sides then this is a win and you can move on.

With the left wing joiner plate/408 rib done to my satisfaction, I will now need to repeat the same process for the right wing. Funny, I was expecting to be working on mod today, but instead I had to re-do everything I did yesterday. The scary part is that I essentially have to do this same thing all over again for the mod, except this time it is in a rib location where I have even less access for positioning and viewing the rib than I did for this one. And so it goes. Vans, today you sucked!

Right Wing LE Rib flanges drilled, started LE modifications

Made good progress on the right wing LE. Got the ribs installed to the skin and the assembly mounted to the right wing spar. Drilled all the rib-to-spar flanges, and then proceeded with the prep of the W408-1-R inboard rib and W-423 joiner plate.

I marked the locations in between the holes where I could flute the rib to straighten it, and applied the flutes. I then straightened and deburred the rib flanges using the flange bending tool and a mallet and straight edge. For the joiner plate, this time, instead of pre-forming it somewhat free-hand, like I did for the one for the left wing, I decided to be a bit more deliberate by taking the rib and setting it firmly on the work bench. Then I used my cleco clamps to incrementally secure the joiner strip all the way around the rib flanges as shown:

The short clamps worked on the very edges, but would not reach the flanges around the sides. the longer clamps worked for the sides, but just barely. I kept the rib flat on the bench and worked the strip around the front, keeping its edge flat on the bench as well. One problem I had before I shot this pic was that I placed wrong strip edge on the bench so the sharpee mark I made was in the wrong place. SO the curve was in the wrong place and I had to rework this a bit after I flipped the strip over so that the mark was located over the rib flange as shown above. So make sure you don't bend it with the mark in the wrong place. Anyway, I seemed to be able to reform it well enough. Even after doing this I found that you still need to apply some force to the round front of the strip to help keep it bent in such a way that will naturally following the curve of the rib. It does not take much, and if you squeeze it in the wrong location you will have to keep reworking it. Here is the pre-bent strip after I finished working on it and clamps were removed:

Then I set out to position the rib and the joiner plate against the right wing LE skin. Then tried to line everything up just as before. Also just as before, this turned out to be a chore trying to position a loose rib and joiner strip all at the same time to achieve the specified measurements to ensure that the rivet holes are drilled in the correct spot for everything. After about 20 minutes of screwing around with it, everything seemed to magically finally fall into place. So I clamped the skins to the rib and joiner plate just as before, re-measured the distance between the rib web and the end of the joiner plate one last time, which requires 11/16 inches all around, and started drilling.

Got all the LE rivet holes drilled, patted myself on the back, and then set out to begin the process of the LE modification that I have been planning for a long time now. For those builders that are following me, if you plan to continue with the stock build of the RV, then you will need to advance to the step in the instructions that says to leave the Le in place and start working on the fuel tanks. For me, this will need to wait until my modification has been completed successfully.

Some things about the mod I will post openly here. Other things will be recorded separately, and I will wait before sharing them after I determine that the steps I employed seem to work correctly. Always remember that anyone following this blog that desires to employ any of the methods I describe, does so at their own risk. Everything I am doing is based on my own research and experimentation, and although there is very little risk of anything going wrong during the build, there is risk that my plans may not work the way I intend them to, and this will only be determined by extensive flight testing long after this mod has been completed.

I am starting the mod with the left wing LE. The process begins by receiving yet another 408-1-L inboard LE rib from Vans, in addition to a piece of .032 x 12 inch x 36.5 inch aluminum sheet. Basically I am going to be replacing the first W-709 LE rib just outboard of the first W408-1-L rib with another W408-1-L rib, cutting out the section of the LE skin in the first inboard bay of the LE, and refabricating a "new" much larger W-423 joiner plate by extending the W-423 all the way across and between both 408 ribs.

It started with fluting and straightening of the new 408 rib.Same process as all the others.This is how I marked the locations where the flutes can be applied, by inserting under the existing joiner plate just far enough to keep it in position so could place pen marks in between all the rivet hole locations:

Here is the aluminum sheet that ordered from Vans. They messed up my order so I need to get another one of these for the right wing,but I also need to order some more .025 sheet as well. I will trim this down to some measurement between 36.5 inches and some other measurement that is a bit longer that I have not yet determined. I order it to be 3 feet and 6 inches long so I had enough extra to work with. The width is 12 inches, and before it is all said and done I may be trimming that dimension down just a bit as well, but I am undecided on that just yet.

Here are some shots of the file that I used to knock down the "bumps" on the front of the LE rib sections:

Here is a shot to elaborate on what I mentioned earlier about replacing one of the W709 LE ribs with another W408 rib. Basically I will have two 408 ribs in the first two inboard sections of the LE.

And then finally something I just could not resist. Can't wait until this mod is done!
This assembly gets glassed onto a removable LE section, but all the necessary substructure mods need to be made first, to ensure that strength will be maintained.

I feel almost giddy now that this is starting to take shape. Looks pretty cool, but will look even cooler as I get this done.

Started prep for the right wing LE

Last night I finished drilling the remaining holes in the left wing leading edge. There were a couple of additional pics I wanted to show regarding the drilling process for the rib flanges to the wing spar. This first one shows a neat trick that I discovered to put more light on the underside of the wing spar. Using my Ryobi flash light (I love this light), I found that you can rotate the head all the way up, and then set it toward the far end of the bay immediately behind the bay that you are working in, and the light shines right on the spot of the wing spar web that you are working on. Worked really well for me.

And next is a pic that shows the bolt and nuts being removed to allow me to get the drill into the two holes either side of center. This did turn out to be a non-issue, and it took about 15 minutes to get both holes match-drilled and replace bolt and nut assemblies. Also notice the light from the flash light.....

And here is a shot of the drill bit and the rough position of the drill in order to drill out these holes in the wing spar web. It gives you an idea of the amount of bend that can be applied to the drill bit to keep the drill outof the way of the airplane parts and still drill a straight hole in the spar web.

Another strange thing happened to me while I was drilling out these holes. I found that I could not focus very well with my glasses on. If I removed them the spar holes were much clearer - so I drilled them all with my glasses off. Could it be that my vision is improving?
I also had a great show this past weekend right over my own house from the EAA B-17 Aluminum overcast, which was in town for its annual pilgrimage and promotional flying tour leading up to Airventure. Luckily it escaped another hail episode,but the weather was threatening on a couple of the days that it was here. Because of that, last Saturday afternoon I was treated to a direct overflight of the B-17not once, not twice, but three times before it departed and headed back to KAPA. What a treat that was. I really love where I live because it is a key reference point for most exhibition flights, including the F-16 overflights of Mile High Stadium during the Bronco games and a whole host of other local T-6 and P-51 activity from time to time. I even see some RVs every once in a while.

With the left wing LE holes drilled, it was time to start working on the LE for the right wing. I removed the vinyl from the inside of the LE, and then I prepped the nose sections of all of the LE ribs. Here is a shot of the LE:

and here is a pic that shows the end result of the smoothing out of the bumps that occur from the nose sections of each rib that are bent over to form the nose of the rib. In their rough form from the factory there are very noticeable ridges between each separate flange as they move around nose section of the rib. I had to back up a page or two in the instructions,but Vans does specifically mention to remove these"bumps to avoid transferring these distortions to the LE skin. They just don't tell you exactly how to do it. This is where I used my standard flat file and ran over the flange joints as many times as necessary, until each section felt nice and smooth to the touch. I ran my finger across each separate section until I was satisfied that it was as smooth as I though it should be, being careful not to remove too much material. Having said that, I did remove a fair amount of metal from some of the flange joints. Each rib was just a bit different so you have to customize the smoothing of each one. This next pic is a bad one but attempts to show the amount of material I removed to achieve smoothness of the nose section of each rib:

If you catch your finger on one of the flanges you need to keep removing material a couple of scrapes at at time until you can run your finger around the entire nose section without catching a ridge. This ensures that your LE skins will also remain smooth.

Tomorrow I started clecoing LE ribs to the skin and setting it on the right wing spar and match drilling those holes.I should also mention that I received a package from Vans with a parts order that I need to start working on my LE mod. I think I have that all worked out, but it is still somewhat involved in order to make it all come together correctly. More on that later...

Lastly  special shout out to my friends Mike and Anetta Rettig, who gave birth to a healthy new baby boy the other day. Best wishes to all of you and Amelia too. I am anxiously waiting on specifics but mom and baby are recovering and when I know more I will post more.

Work continues........looking more and more like wings everyday. Fuel tanks are getting closer to the top of the work list.....

A super busy day at the airplane factory.......

......But to look at the pics you wouldn't think that I got too much done. I have a lot to post tonight with a large number of builder tips. Hopefully builder that read this will find them useful.

It started with a review of Vans instructions regarding the leading. I reinstalled the Left wing LE ribs to the skin in the cradle, and then I realized that I was going to need to remove more vinyl from along the edges of the skin that overlap and attach to the main wing spar. Some older videos/DVDs cover a process to attach the LE to the wing by using cargo straps to wench down the skin onto the main wing spar, saying that this is needed due to the extreme tight fit of the LE to the wing. Well, the cargo strap technique is not used quite so much any longer since all the building of the LE and the fuel tanks is done in the cradle, but the extreme tight fit to the wing spar is definitely still there.

I moved the LE to the correct position on the wing,which I had done before, and clecoed all the rib-to-spar flanges to the wing spar from underneath, except for 2 that I will explain later. Up till now I had only clecoed the end rib to the wing spar just to get an idea of the fit. I had not clecoed the skins to the wing spar, and that is where things get very, very tight. Then I clecoed the skins to the wing spar, starting with the bottom skin holes. In retrospect I probably should have started with the top skins first, but I don't think it would have made any difference. Once the first few clecoes were in place it got easier, but was still very tight. Then, when I tried to cleco the other side, this was almost impossible. I almost thought about getting the straps out to cinch then down far enough for the clecoes to fit, but eventually I was able to get them started without needing the straps. This was still very difficult to do, and after having done it I can now appreciate when they tell you that the LE is put on very very tight.

Vans instructions say that the flange of the 2 LE ribs just outboard of the tie down bracket does not match the holes in the wing spar, so this is yet another case of using the holes in the wing spar to drill the new holes in the rib flange and abandon the others. A note to other builders - 3 of these holes still DO match the same holes in the wing spar. They are the ones in the center. Only the two holes on the ends do not have pre-drilled holes in the rib flange. So you can cleco the holes in the middle to keep the flange secure while you drill out the other holes on the ends.

So how do you drill them out. Well this is where it gets interesting. You have to drill them out from the botttom of the wing spar.Also, to avoid the contact of the drill chuck with the main wing ribs, you have to use a drill bit extension. This actually turned out to be fairly easy, but you do have to pay attention. I used one hand to guide the drill bit and the other to run the drill while bending it just the right amount to keep the drill away from the rib flange. Here are some shots of the clecoes:

And here is the problem rib. Can you see the problem?

For all you future builders - make a note - when you figure out where to drill your holes for the angle used to mount the wing to the stand, make sure you position the bolt holes so they are not directly underneath a rivet hole. I was only able to drill out the three holes with the clecoes for now, and I will have to remove the bolts one at a time while ensuring that the wing remains properly on the stand. Since the wing is also secured on the bottom support angle of the wing stand this should not be a big deal - we'll see.

Here is the 12 inch #30 drill bit extension I used to match drill the holes.

Here are the clecoes for the LE skin on the bottom side. Vans says to cleco every third hole.I can never figure out if this means third hole AFTER the one that is clecoed, or third hole including the one that is clecoed, which basically means every other hole. Either way, it works.

Here they are on the top side of the wing, where they butt up right next to the top wing skins, exactly like they are supposed to. This never ceases to amaze me - that the match drilling and cnc holes are so precise that everything just lines up the way it is supposed to. I really liked seeing this. The skin with the vinyl removed is the lower wing skin, and the topis the LE skin:

And now for the less than fun part of the day - fitting the inboard 408-1-L rib and the joiner plate together. This rib has absolutely no holes in it whatsoever, the position/clamping/securing of this part is critical to ensuring that the holes get drilled in the correct location on the flanges. This becomes difficult when you try to position the joiner strip between the rib and the skin. You end up losing reference of the location of the rib and the edge of the skin because the joiner plate gets in the way and extends well beyond the edge of the inboard LE skin. You are trying to make a sub-skin that the fuel tank skins will slide over when the fuel tank is fitted to the wing right next to the LE. The two skins should butt right up next to each other. This joiner plate also gets nut plates attached to it later on.

All I can tell you is that this was a pain in the ass. The joiner plates is made from 1.5inch x 36.5inch long .032 inch thick aluminum sheet. I deburred the edges, and then marked a line 1/2 inch from one edge, per the instructions. This line is a guide line for the holes in the LE skin so you can line up both the joiner and the rib correctly.

Here is the strip with the reference line drawn;

The hard part of all this was getting the strip to fit in between the rib and the LE skin. I ended up doing something different than the plans by using the rib on the work bench as a form and then taking the strip and forming it around the rib to establish the necessary curve around the nose of the rib. The ends of the strip should end up matching the end of each side of the rib flange after it is all in place, but you are not sure where they will end up when you start fabricating everything. Once the strip is pre-bent to the shape of the rib, I placed the strip inside the wing skin, and then I took the rib and started inserting it from the nose first, followed by the base, which is different than how Vans tells you to insert the rib. This most likely resulted in the bending of my rear rib flange just a bit, but was not too bad, so I left it that way when I drilled it. I will bend it back into shape after I remove it for deburring later on.

The plans tell you to line up the plate by moving it until the line shows up under the rivet holes in the wing skin. Then you verify the position of the rib by ensuring that the distance between the rib web and the end of the joiner strip is 11/16 of an inch. I must have measured, clamped, remeasured, repositioned, and re-did everything all over again about 20 or 30 times. I used my ruler to verify the 11/16 inch measurement, and when I thought I had it all lined up and put a couple of clamps on as shown below to keep it from moving:

I found this to be very perplexing because you cannot clamp the rib flange to the main wing spar at all,and I wanted to make sure that the flange would not move when I started drilling it. So clamping the skins was the only way I could try to secure the assembly and keep it  from moving. Then, when I was satisfied that i had everything as lined up as it was going to be I started by drilling the holes for the spar flange:

That seemed to go OK so I then started drilling all of the skin/joiner plate/rib holes from the top side and then around to the bottom side. I was very worried that the holes may not be lined up on the rib flanges correctly, and I do think that they are a bit on the inside and too close to the rib web, but I will know more when I remove the rib after all the drilling is done.

And finally, here are some shots of both sides after all the drilling was done:

And one last shot of the wing with a mostly drilled out LE:

Tomorrow I finish drilling all the remaining holes, and then I start working on the right wing leading edge adn do everything all over again, hopefully better than I did this time.

Starting to work on the Leading Edges

I have not posted anything in a while because the work I have been doing has just been duplication of the left wing deburring on the right wing skins and ribs. I finally finished all that deburring today, so the wing skins and ribs will be ready for dimpling soon, after I manage to prime the insides of the skins. I removed the bottom wing skins from the left wing per Vans instructions, and left the top skins on.You need to have access under the wing spar for fitting and drilling the leading edge ribs to the spar, so the bottom skins are removed to allow this.

The next step was to remove all the vinyl from the inside of the leading edge skin. Being my usual frugal self I decided to use my soldering iron to remove the vinyl only from the rib lines, leaving the rest to protect the skin from any scratches or dings. I have had the left wing leading edge in the cradle now for a very long time, with the ribs clecoed in place. I remember I wanted to see how easy or hard the ribs could be clecoed to the LE skin. THis also verifies how well you straightened all the LE ribs. Contrary to Vans instructions at that time I left all the vinyl in place on the skins. Some of the holes were difficult, but I managed to get all ofthem installed.

Either Vans or some other builder also suggests to knock down the flanges that are cut into small separate flanges that go around the circumference of the very front part of the leading edge skin. I had straightened all of these separate small flanges long ago, but had not done any further prep work to debur or smooth out the fronts of the ribs. Because of this, and the need to remove the vinyl for correct fitting of the ribs to the skin, I needed to remove all the clecoes and remove each LE rib. This went pretty well, but some of them were difficult since the holes have not been match drilled yet.Before I removed the clecoes from the ribs I took the soldering iron and used each rib flange as a guide to melt the vinyl. This also worked pretty well.

You are supposed to knock down the rough edges of each of these small flanges because if you don't small bumps will appear in the LE skin that apparently are somewhat visible after painting. There is also a possibility that stress risers will forming that area and possibly cause the skin to start cracking. If run your finger around the front of each rib you can feel the high spots created by the bends and relief holes of each of these flanges, and so the acid test for smoothing these out is to feel no sudden stops with your finger and everything should feel smooth as your finger follows the contour of each rib.

The only question now was what method to use to smooth them out. I had already tried using the scotch brite wheel to do some of this, and it just did not work very well. Tonight I decided to try using 220 grit aluminum oxide sandpaper. My past experience with using the sand paper  for removing or smoothing large areas with significant amounts of material to remove is that this takes forever to do,even with 220 grit. You also need to be careful because you do not want to remove too much material.

So after the first rib I gave up on the sandpaper, and switched to a standard sized flat file, and two other smaller jeweler files that I have used in the past for the smaller ribs for the tail section. The flat file actually did a nice job of knocking down the high spots and smoothing out the transition between each small rib flange on the nose of each rib. I kept running the file over each adjacent set of flanges until the entire rounded surface felt smooth. I used a round jewelers file to smooth out the relief holes.

I managed to smooth out all of the ribs for the left wing LE, and now that I have all of the vinyl removed as well, tomorrow I will re-cleco all of the ribs back into the LE skin and fit it to the left wing spar per the instructions. Then I will be able to match drill the holes. There are some questions that I may need to ask Vans about next week. I am not sure if I will need to kerf the LE skin so that it does not curl up on the edge against the spar, and I am not sure how much,if at all,I am supposed to debur the edges of the skins,since part the process for all this is to ensure that all the separate skin sections for the wing, LE, and fuel tanks all butt up against each other without any gaps. Gaps between the skins sections will generate drag, which the enemy of speed.

Anyway, all for now, more fun work to do tomorrow. Man am I glad that all that deburring is done. My fingers are shot from doing the back sides of the wing ribs by hand.

Right wing top skins deburring progress

Just more of the same - stripped the vinyl off of the larger outboard top skin for the right wing tonight. I have also been watching episodes from the series "From the Ground Up," which, if you have read my early posts, you know that this is one of the catalysts that convinced me to take this journey of building my own airplane. This series is always good motivation for me to continue on, no matter how mundane or insane my current tasks appear to be. At the end you get to watch the finished product (An RV-8) take to the skies for the first time.

Tomorrow I will debur the holes in both top skins, all 80 million of them. OK,so I am exaggerating just a bit, but it sure seems that way. Here is a pic of the right wing top skin with the vinyl removed:

Next is a pic of the way that I left the bottom skins mounted temporarily to the left wing. As soon as I finish deburring the right wing skins the bottom skins of the left wing will be removed per the instructions so I can begin the process of fitting the left wing leading edge. Sure will be nice to switch from the main skins to the leading edges.

Since they will be coming back off soon I only clecoed the top rows of the skins in place. No need to lock down the entire skin since they will becoming back off soon.

Really getting the itch to go flying soon,but I still have some things to take care of first.

On a sadder note, it looks like my washing machine, hot water heater, sprinkler system plumbing, and probably my car have all decided to breakdown at the same time. Sucks to be me I guess. Unfortunately no Oshkosh trip for me this year - just can't swing it financially. I am, however, still planning a trip to Boise Idaho in the fall to visit my brother and his family, and to hook up with one of the transition training pilots listed on Vans website to see if I can get some time in an RV-7A to familiarize myself with the flying characteristics. Looking forward to that.

Bottom skins of the left wing all deburred

I managed to get both sides of the bottom left wing skins deburred - even before my back decided to give out,which I thought would happen a couple of times. On the tables and saw horses I was using, sitting in a chair would not quite work, and standing put me just a bit higher from the work surface than I wanted to be. You can't just prop up these skins vertically like you could with the other skins from the tail, so this was a little more back breaking. Anyway, at least I can report that the drilling an deburring of the wing skins in 50% complete. I still need to do all 4 skins for the right wing, but progress is progress. 

Here is  pic of the larger outboard bottom wing skin with the vinyl all stripped.

It was kind of a dreary day here - filled with nothing but rain. Sure am tired of that. Next task is to debur the dreaded bottom half of the wing ribs. At that point I have some decisions to make. I can start on the right wing and repeat everything I have done on the left wing up to this point, or I can continue with the left wing and work on the left wing leading edge. The one thing I do NOT want to do is to start the edge deburring and dimpling of the wing skins until I have fit and drilled the leading edge ribs and skins. It is easy to jump too far ahead and start doing the wrong thing at the wrong time, so this is a point where reading ahead in the plans and instructions will help determine what steps you should and should not take.

There is still an amazing amount of work to do.....but at least it's getting done.