Scott & Tanya Card RV9A build log (N4822C)

I really haven’t accomplished much this past week. I have been working on very minor stuff, but don’t really have anything to show for it. I did make the stick boot rings and deburred the forward seat pans. I had my second Tech Counselor visit the other day. Many thanks to Deene Ogden.

Moving forward with the canopy frame (roll bar), I drilled the forward section to the joint strip. I also drilled the center joint plate on the forward section. At each step of the way, I continued to check total width and height measurements very carefully. With everything drilled, I took it all apart and deburred all holes and edges. Then, I machine countersunk all of the frame holes. There is a fun trick, machine countersinking an inside and outside curve. Patience is the key.

I primed the inside of the frame parts (anything I couldn’t prime just before interior paint) and got the forward sections assembled back on the bench for riveting. Solid rivets are squeezed on the forward section and attach strip, then the aft section is installed to close up the channel. Pop rivets are used here. (Tool Alert) I am totally kicking myself for waiting so long to purchase a pneumatic pop rivet gun. $30 at Harbor Freight right up the street. Just laziness on my part. I was looking at all of these pop rivets that had to be installed on the cabin frame and was not interested in spending half of my Saturday squeezing these things only to end up with a sore arm. The pop rivet gun is AWESOME! I wish I would have had this thing on the rest of the project. Just pull the trigger and, pow, done, on to the next one. It took all of ten minutes to set all of the pop rivets. Super cool.

At about this point, David (-7A builder) came over for dinner and an evening of great RV conversation. I very much enjoy talking RV construction in the garage, and we did for the better part of four hours :).

Back to the project at hand, it was time to figure out how this contraption gets installed. I spent a lot of time clamping, measuring, and marking the attach brackets to be sure I knew what I was doing. I found (as others have) that there is a bit of interference between the brackets and the seat back brace thingy. I used the Dremel to cut out a little notch on each side to clear the bracket. With some final careful measurements, I drilled the brackets to the fuselage and the cabin frame. The top bulkhead brace is required for final alignment before drilling the brackets, so I match drilled it at the same time. Note that my kit includes the tip-up AD modification where the top brace attaches to the bulkhead and top skin.

Once all of the cabin frame attach stuff was complete, I decided to fabricate a cover for the top brace. Not too much to it, but it took a little time. I’m thinking I might want to put a light or something overhead. To complete this update, the label printer that I ordered arrived. This is the same device that Walter used. It can print on shrink wrap tubing. Great for labeling wires.

 

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

 

After finishing fabrication of the brake pedal assemblies, I fit them to the rudder pedals so that I could align and drill them for the brake master cylinders. The plans/instructions are very vague here with respect to alignment. After some head scratching (analysis of final installation geometry), I just went for it. I setup the rudder pedal weldaments on the bench both hanging straight down and aligned them with a plumb bob. Then I installed the four brake pedals. The big question is, what angle (if any) should the pedals be at relative to the plumb line? Part of the thought process here had to include that when they are mounted in the plane, are they hanging straight down or are they forward just a bit? This isn’t exactly clear in the plans, but if you were to pull the full size plans into AutoCAD (as I did) and did some real distance and angular analysis, just for the fun of it of course, you would find that the pedal assembly is all rotated at the same angle as the member it is mounted on. Ok, so what does all that over analysis mean? The plans suggest that if the assembly is built with everything lined up on a plumb line on the bench, installation will work out as illustrated in the plans. This means the rudder pedals (bottom tube) should line up and the brake pedals should be straight up and down on the plumb line as it sits at no angle on the bench. Ok, none of this really matters all that much, but I’m just amusing myself.

I configured the pilot’s side brake pedals plumb with the rudder pedals when drilling the bolt holes for the master cylinders. However, I chose to angle the passenger side brake pedals just a little further forward (about 1/4″ at the top of the pedal). The real test of all this is how it feels in the plane, but you would need for the seat cushions to be figured out in order to get the proper feel. With everything drilled and test fit, I put the rudder and brake pedals away for painting and installation much later.

Next, I moved on to the rear cabin frame (roll bar). The first task is fabricating a bunch of little parts from various angle and sheet stock. Luckily I figured out that the two F631-E joint plates are pre cut. Many thanks to Tanya’s great organization skills and keeping sub kits and their parts together. I went to retrieve the cabin frame parts and, hey, what are these two unmarked little squares of AS3-063 for…, what do you know, they are exactly the right size for F631-E. Otherwise I was thinking that I would need to fabricate these from a larger sheet, not that that would be any big deal either. Fabricating the attach angles (AA6-188) is another place where having a nice robust band saw is a life saver. If you don’t have one, I would highly recommend beg, borrowing, or stealing some time on one when you get to this point (Zach and David!), as it makes it quite painless. As I was cutting them out, I was trying to imagine the pain of those that would spend hours gnawing on these with a hack saw. You need the attachment angles fabricated so that you can take an accurate measurement of the true width that the canopy frame needs to be.

If you think about it, these cabin frame pieces are kind of interesting in that they are surely formed in a much different process than any other parts so far. I’m guessing that they must have been formed hot as opposed to cold (as most other parts are) because the amount of stretching and shrinking of the outer and inner flange radius would surely fracture and severely deform the part if worked cold, hence all the fluting that we do on other parts. I think you could make a real mess if you were to try to straighten them out more than they already are. The instructions say to just clamp them to a flat bench for match drilling.

I spent a couple of hours trimming and tuning the joint end of the aft pieces in order to get the overall width correct. There are a few dimensions that need to be considered all at once. I have included some pictures of the creative clamping that I had to do. In order to mark the rivet locations on the flanges, I made a little sharpie pen jig for the centerline, and used my calipers as small machinists dividers for the rivet spacing. I figured out the spacing by first roughly using a piece of string to get the length along the curve and dividing by the number of rivet spaces. I took that spacing measurement and laid it out on the flange using my “dividers”. Of course, the string isn’t very exact, so I then measured the error on the part and divided the error into the spacing measurement. I reset my dividers to the new (corrected) distance, and off I went.

Drilling the attach strips to the frame was kind of a no brainer. I did pre-bend the strips and used a bunch (as many as I had) of spring clamps. I have completed drilling both of the attach strips to the aft frame parts. Next is to drill the forward half which I have already trimmed for overall width.

 

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

  

 

If you haven’t figured it out yet, I post the pictures then try to write sequentially based on the pictures, so follow along:

I took about twelve days off of “real work” during the holidays to pretty much just build. I haven’t taken that much time off in years, so it was pretty cool. I’m not sure I was as productive every day as I could have been, but that wasn’t the idea, I had a blast nearly living in the garage. Many thanks to Tanya for keeping me fed. Ok, blah, blah, what did I get accomplished…

First off, a courtesy picture for the FAA. Yep, that is me, very comfortable with a pair of cleco pliers in my hand. I decided to drag out the electric aileron trim stuff. Yes (David), this would be much easier to setup and install while working on the center section up on the bench long ago, but I was feeling lazy that day, so now is the time, before I install the aft seat floors for good. I ran the servo to both of its limits to identify the mid point, then ran it back to the mark. I fabricated all of the little parts under there (not pictured) and setup the seat ribs for mounting. This was a no brainer all around. It is very cool how easy this basic construction stuff is getting.

Side note: As you can see, I have completed most center and aft fuselage tasks. I think the height that I have the fuselage set off of the floor is nearly ideal for working in it without having to climb in. I have only been in this thing once or twice, and pretty much only for the fun of it at that. Everything, so far, has been very easy to do over the side. I think the bottom is about 14″ from the floor at the spar.

After much deliberation, I went ahead and riveted the baggage compartment floors on for good. I was definitely thinking that I should have sprung for a pneumatic pop rivet puller, but I didn’t. Tanya cut the sound proofing (1/4″) for under the seat bottoms and I glued that into place.

Next up was the aft seat bottoms. I first cut all of the hinge stock for the bottoms and the seat backs all at once. I used the right angle grinder with a cutoff wheel to cut to length. That worked great. I marked and drilled all of the hinges to the seat bottoms. I noticed, just before riveting the hinges on, that I had marked and drilled all of the bottom hinges about 3/8″ too far over. I had measured from the wrong location. After the normal personal deliberation, I got to work moving them. I just re-drilled new holes in the correct location in the bottom skin. So there are some “extra” holes under the hinges, no big deal.

Once I hade the seat bottoms ready, I decided to go ahead and fabricate the seat backs. They are very simple, but nothing is pre-punched… So I spent the majority of two days working on just the seat backs. One of the vertical support pieces (1/8″ x 3/4″ angle) calls for a notch to be cut out to clear the bottom hinge. I easily took care of the notch on the band saw. That was fun. I never knew I could cut a paper thin piece of aluminum on that thing. With all the parts fabricated, the riveting was quick and easy. I did use the C-frame to rivet some of the middle rivets for the brace hinge.

I took nearly a full day deviation from building to do a little upgrade of my shop entertainment. My garage radio was previously a little alarm clock thing that was very lame in the audio department. I finally broke down and got a new XM radio. I also ran up to Best Buy and picked up one of the cheapest real receivers that they sold and a good pair of Bose speakers. The speakers cost more than the receiver. I did some hacking of the cabinet above my work bench to provide a home for all this stuff. Now I have real audio that sounds great (for a garage).

Back to our regularly scheduled program. I riveted the aft seat floors down for good. Things really start to stiffen up when these floors go on. How about a full test fit of the seat backs? Ok, that is very cool. I couldn’t resist jumping in and making some airplane noises. Once I was done messing around, it was back to work. Next I fabricated the forward tunnel cover. It had some minor clearance issues when I got around to installing the flap housing.

The flap actuator mechanism and housing was next. There are a number of small parts to be fabricated for this setup first. I made the correct angle in the upper attach bracket with the vice and a big hammer. It is surprising how much force is required to bend AS3 .063. I also drilled the hole in the actuator for safety wire. The drilling of the hole is really more like drilling two holes that meet in the middle. Mark, clamp, drill, deburr, rivet nutplates, just like it is depicted on the plans (instructions?, we don’t need any stinking instructions at this point.) I’m not finalizing the flap hardware yet because I’m going to remove all this stuff when I get ready to paint the interior later. I ran the flaps up and down with a battery. Yep, it all works just like it should. After I completed the flap assembly, I found from other’s experience that there might be a clearance issue with the rivet heads on the upper forward bracket and the canopy latch mechanism. So, I pulled it out and replaced the 470 rivets with flush 426 rivets. I couldn’t find anywhere on the plans where these rivets were specifically defined.

On my last day of this build-a-thon, I was somewhat perplexed as to what to do next. The instruction sequence has you do mounting and fitting of the empennage and wings, but those are all nice and tucked away in the house right now. I don’t really feel like dragging them out just yet. Surely there is some other stuff to do. I have kind of passed a point were construction sequence has become very blurry. Ok, I decided to go back and fabricate and setup the brake pedals and brake master cylinders. I got all of the parts fabricated, drilled, and deburred. Another short session will finish the brakes and rudder pedals. I won’t be installing them until much later though. Then, I think I’m going to build the roll bar next.

After I get the roll bar completed, I’ll be moving on to the forward upper fuselage (read Instrument Panel!). Oh, I am also considering when I want to do the main gear mounts. I would prefer for them to not be bolted in place when I get ready to paint the interior. I might try to do a pre-fit for drilling and such. We ordered the finishing kit a few weeks ago. It is supposed to ship the “week of” February 13th. It is going to be time to really start getting stuff together for the instrument panel before long. I’m planning on a three display GRT EFIS with a panel cut by Affordable panels. This will be nearly an exact copy of Walter’s panel.

Back to the real world and “real” work.