Mid Fuselage Side’s

Time: 4 Hours

Today I started on the fun deburring process of all the parts that make up the mid fuselage side walls including the bulkheads and arm rests.

I then countersunk all the nutplate holes in the various parts that I just deburred. When that was all done I grabbed the side skins down from the ceiling racks where all the flat skins get stored.

I got the soldering iron out and removed the blue film on the exterior side just over the rivet holes. The inside of the skin I removed the entire film as I will be priming and painting the surface as it will be seen in the cockpit area.

That was enough for today. Tomorrow I will debur all the skin edges and roll the aft corner of the lower part of the skins. This will make the transition from square to rounded edges for the tail cone.

Longeron Drilling #2

Time: 6 hours

I finished up the left lower longeron today by removing it and Deburring all the holes and edges. I also deburred the holes in the lower skin and weldements where I had drilled through. One last task before reinstalling the longeron to continue the build was to round over the last 2″ of the aft end of the longeron. This is done so the skin that starts to roll up here makes a nice transition and doesn’t have a sharp corner.

I marked off the section and hit the scotch-brite wheel and made the transition.

I put that longeron back in place with clecko’s and the temporary bolts in the forward section. I also put the 2 flush screws in place at the gear tower weldement. When I was done with that I repeated the entire process on the right side with nice results. I then grabbed the spacer that goes between the gear tower weldement and the gear tower plate and deburred both the left and right one. I also reamed all the 1/8″ holes in the gear weldement to clean out all the powder coating. I then placed the aux longeron, spacer and plate in position on the left side. You clecko from the inside to make it easier to put the skins on for fitting. I repeated the process for the right side but had an issue. When everything was in place the aft end of the longeron was almost a 1/4″ higher than the gusset it will be riveted to.

After discussions with my buddy Glen we decided that it was the spacer that was preventing the longeron from settling where it needed to be. My guess is that the weldement is off just a little and it’s tweaking it a little. So my fix was to shave off a little of the spacer so the longeron could slide down as needed. I made several small attempts at this until I got it just right and the fit was good.

After match drilling a few holes on the mid-braces I separated the center section from the forward section and cleaned up all the mess.

The next step in the plans are to build out the walls of the seat section including the skins, vertical bulkheads and arm rests. I took some time and located all the parts for this section.

That’s where I called it a day as all those parts need deburring which I will get to in the next couple days. Another good day and Fall is playing nice with beautiful weather.

Longeron Drilling #1

Time: 4 Hours

I got 4 hours in the Hangar before giving to grabbing the Harley and hitting the road to see the fall colors on this 80° Sunday. First up was to do some final tweaking of the 2 aux longerons. I wasn’t happy with the way they were lining up with the aft gussets and needed a little twisting for them to line up just right. After that it was time to line up the lower longerons and clamp them into their final position for match drilling. You want to make sure the longeron is tight against with engine mount as well as the gear tower weldements. I used various type clamps to hold the longeron in place after lining it up.

You start with the aft most hole of the bottom skin and drill up using the skin as a guide into the longeron. You then move to the forward most 4 holes that go through the skin, the longeron and the engine mount. Opening those holes up with a #12 drill to allow for AN3 bolts. I inserted the forward and aft bolt in those 4 holes to maintain the longeron position.

Now that I had the forward end and aft end locked down I just worked my way down the longeron drilling each hole and cleckoing them as I went.

There are 2 holes drilled up through the gear tower weldement that got opened up to a #19 hole. These will have screws in them and will need a flush head on the underside of the skin. This will allow the landing gear to sit flush on the underside. So after drilling those holes I grabbed the #19 countersink bit and cage to drill those holes.

That’s where I stopped and went for the Harley ride. Not a whole lot today but any work in the Hangar is good!

Longeron Bending

Time: 6 Hours

There are 4 longerons, aluminum angle, that run along each side of the aircraft. These structural angles tie all the parts together and create an incredibly strong substructure. On each side there are a lower longeron running from the firewall aft to the center section at the bottom of the gear tower weldements. A mid longeron that runs the same length on the top of the gear tower weldements. A upper longeron that will run from the firewall to the tail cone and a aft mid longeron running the length of the tail cone. The lower forward is the first up and comes with a bend already in it for the bend in the floor. You have to create a couple twists, one at each end as well as spreading the angle at one end open. Van’s gives you the angles in relation to 90° to make the twists. I bought some bench vise jaw protectors that are plastic and have magnets to hold them in place. I also bought a 4lb dead blow hammer and a 15″ adjustable wrench at Harbor Freight.

The first bend is on the forward end at 7.25° off of 90°.

You then place the aft end, open face down, on the cement floor and use the dead blow hammer and hit the vertex of the angle and essentially open up the face and increase the angle. There is a guide on the plans for the correct angle and I just kept at it until it was perfect. Now you can put the twist in the aft end that you just opened up. It is in the opposite direction at the forward end. After a few trial fits and a little bit of tweaking I got the left side just right.

I repeated all those steps for the right side.

I then moved to the aux middle longerons, they just needed a little curve placed in them. I didn’t take any pictures of that process but just used the bench vise and a little pressure at 2″ increments to make the bend. I then grabbed the 15′ long longerons to do their bends. There are 4 bends that need to be done per longeron. There are 2 reference spots measured from the forward end. At each of these spots you have a bend in not planes, horizontal and vertical. I laid out a chalk line on my garage floor and used tape to make some reference lines. At the end I used tape to make 4 different measurements from center that represent to amount of deflection for each of the 4 bends.

I used the bench vise and my dead blow hammer to make all the bends. I worked in small increments and checked my progress. All in all I think they turned out good and will tweak them as needed as I install them with the aft tailcone bulkheads.

There are plates that cover the outboard edge of the center section bulkheads and the gear tower. You need to curve the top of these plates to match the curve of the bulkheads. I used a piece of oak 1×4″ wood and two 1/8″ aluminum pieces to create a bending tool.

I placed all the plates in place as well as the 4 lower gussets and the 2 larger upper gussets, which needed curving as well.

I then clekoed the forward section, center section and seat substructure to each other.

That’s where I stopped today, another great day in the Hangar. On a side note the RV-8 is not the only thing requiring metal work lately. While on my 3 day trip to St. Louis I was putting the engine covers on our Lear Jet 45 when I struck my head on the underside of the left engine on a oil drain tube the size of my pinky finger. After running my hand on the freshly made ouch I realized I was bleeding pretty good. Low and behold I had a 2″ laceration on the top of my noggin. This required 9 staples to repair and a stupid painful tetanus shot.

Center Section/Seat Substructure Done

Time: 8 Hours

Another great day in the Hangar today. We had beautiful weather here in Chicago which made for a nice day with the door open. After doing some research last night and consulting with my buddy Glen I increased the space between the center section to 1.440″ to give that extra little bit of room for the eventual wing spar attachment. I also abandoned the PVC spacer idea in favor of using the bolts and several nuts to maintain the space. I did this as it was just going to be easier to get the space just right as I adjusted things.

Once I had all 8 bolts in I riveted the flange and the flange nutplates. I taped off the ones that don’t get riveted now so I would have to drill out rivets later.

That basically completes the center section, the only step left was to install the snap bushings to protect items that will travel through the section.

I set the center section as side to start the assembly of the seat substructure. When I ordered the fuselage kit I forgot to order the electric trim option so I made that order this week and it arrived on Friday. That was the first task at hand with this section. It’s funny that Van’s has this kit that has instructions and plan drawings from 1998 and now have totally different parts for the seat ribs. Back then you have to measure and use a template to cut holes for this trim kit. Now the ribs come pre-cut for it, so you have to do a little interpretation to figure things out. Once I did just that I had the 2 brackets, one for holding the trim servo and the other a pin guide, in place I match drilled all the holes.

A little time cleaning up all the edges and holes and off to the primer table.

While the primer was drying I moved on the the assembly and riveting. First up was the bulkhead and the 2 rear spar attach doublers along with the seatbelt attach point and corner gussets.

I riveted the nutplate’s on the rib angles next.

At this point you rivet all the parts for the 2 forward inboard ribs. They get the rib angle, the seat belt side attach points and a small bracket.

At this point the plans have you systematically add all the parts and rivet as you go. I was able to get some with the squeezer but moved to the double offset head for the rivet gun and my tungsten bucking bar.

I didn’t have to drill out any rivets in this section. I did however have the gun bounce off the rivet head and make a mark on the rib when I was riveting the servo bracket but not too bad and a little touch up on the primer and all was good.

So I was on a roll even though I had 6 hours of solid work in. The next step is to flip the section over and put the two bottom skins on.

I used a sharpie to mark the holes that get skipped now for later riveting. I then started the riveting working as deep as my arms would reach.

I was able to reach all but about 19 rivets with it laying on its back.

I tried to back rivet the rest but only had access to a couple as the bulkhead was to tight. I left the back rivet tape on to hold the rivets in place and stood the whole structure in its aft end. That gave me access to the rivets and it would stand on its end to give me time to get the gun and bucking bar in place. Not the easiest task but it worked. I found that the rivet that was dead center in the bulkhead, on the skins, didn’t actually have a hole in the bulkhead flange but rather a slot cut into the flange. When I dimpled the skins that dimple now sat up a little as the slot wasn’t as wide as it needed to be. I didn’t catch this when the skins were match drill since the dimples were not done. So I drilled out that center rivet and went to a flush blind rivet. This allowed me to put a lot of pressure on the skin and rivet at the same time to get the skin to sit more flush. You don’t rivet the outboard ribs at this time so that’s as am far as I could go on the skins. I only had to drill out 2 rivets as the skins were a little bouncy causing the gun to slip a little.

I cleaned up the bottom of the skins and flipped it back over to put it in its place. The RV is starting to take shape and look like something.

Wow I really love days like these in the Hangar and you get to see real progress!