More work on the F-623 corner ribs - 7 hours

Quite a long build session in the garage today with little progress to show for it. This is a tedious process working with these F-623 ribs.

I need to complete the correct and final trim to the forward flanges of the 623 corner ribs, and to do that I need the floor at the correct angle. Fortunately for me I have some botched parts from a previous F-706 bulkhead attempt that I can use. I dug those out of my scrap bin and used them to cleco the F-770 side skins on. This gave me the best chance at getting the correct angles to work with.



I could then easy mark and trim the flanges of the corner ribs to meet the F-705 bulkhead flanges.

I was then set up to easily mark out the aft ends of the F-623 corner ribs with perfect reference to the F-706 bulkhead.



I was then ready to match drill the bottom skin to the F-623 corner ribs. This isn't as straight forward as you would think. The ribs don't quite match the edge of the skin as the drawings indicate. This took a bit of messing around on my part. Clamping, checking, repositioning, repeat....till I was happy.

A closeup of my rough fit. I still need to round the corners.

I need to trim the inboard flange of the corner rib on the aft end to prevent contact with the baggage rib.



I was then ready to match drill the corner ribs.

Next step I needed to make the Forward F-623A attach straps. I deviated from the plans and opted for a larger strap that ensures good edge distance. I started first with cutting some cardboard scrap as a template.

I could trace the holes and confirm the proper edge distances. I then used 0.032" scrap and cut the larger wedges out of that.

Check fitting...Looks good.
 
After match drilling and some TLC on the 3M wheel, here's how it looks.
 

 Now to work on the Aft F-623A attach straps. Think this will be just as tedious.

Cutting the forward corners of the F-623 ribs - 2.5 hours

Feeling confident on the marks I made yesterday after re-checking them today. I made the initial cut. I purposely didn't cut enough but left myself in a good position to test fit, mark, cut and check. Eventually it was perfect.

Next I need to trim the flanges of the F-623 ribs, but I need to ensure the correct angles and the only way to do that is to cleco on the F-770 side skins. Once I did that, I could transfer the rivet hole locations on the flanges of the F-623 corner ribs....that would allow me to flute them in the correct location.

Began work on the F-623 corner ribs - 1.5 hours

Now that everything was match drilled, I flipped the assembly and began to figure out the F-623 corner ribs. I need to trim these as they need a little extra TLC being that there are shared from the older non-drilled/raw RV-6 parts. Of course I want to be careful and not trim to much, so I took a conservative approach. Check three times, and mark.



 

Match drilled the F-776 skin - 2 hours

Just mindless match drilling of the F-776 skin. I started front to back, skipped every other hole. Then once I was done on the first pass, I caught every other outstanding hole on the second pass.
 

Cleco'd the F-776 skin to the center section - 3 hours

I struggled to get the F-776 bottom skin onto the centre section. I tired a couple times to get it cleco'd working front to back, but the holes were just too off when transitioning aft of the F-705 bulkhead. I then disassembled and tried starting in the middle at F-705 but when I got to the F-704  center section assembly, the holes were again too off. I double checked my assembly, the F-916 spacers were in.

The issue I seemed to be having is that the radius of the F-716 seat ribs is not tight enough and this is reflected in the fit of the ribs to the F-704 center section. The holes do not line up by themselves, however with some hand pressure they line up.
 
I need to figure a way of squeezing this up.

After some head scratching I thought of clecoing the top row and bottom row first...this will help evenly squeeze the assembly as I celco'd row by row to the middle. As I started, the middle of the skin was a bit proud off of the F-705 bulkhead as the tight skin wanted to bow the structure the opposite way.

After a few more rows of cleco's, holes were starting to line up very well. Still tight, but much better than they were. So I clecoed the middle rows.

And just like that, the skin went on. Whew!

Devinyled the F-776 centre section bottom skin - 2 hours

Pretty self explanatory. I de-vinyled the F-776 center section bottom skin on the kitchen table...in front of the TV. A tedious process but needed. At least it's not frustrating.

Assembled/Cleco'd the center section frame - 1.5 hours

I was eager to get the center section assembly together to see how it all fit and looked. As well, by putting the seat and baggage panels helped me to visualize how I was going to make the panels removable.

Flutted the F-716 ribs - 1.5 hours

An easy day today....again.

I straightened and flutted the flanges on the F-716 ribs.

Modified the F-716 ribs for the control access - 1.5 hours

Small day today on the build, I cut the two (2) F-716 ribs for the removable piece that allows installation of the stick controls. I used the band saw to make the cuts and then used the sanding station to clean things up. A final run through with the 3M wheel cleaned it all up.




Although a small build day, it was a heavy research day. First I needed to figure out how may F-716 seat ribs I wanted to modify to allow Stick control access. The plans indicate two, however many folks modify four. I finally settled on only doing 2 ribs...I can always easily modify the other 2 ribs at a later date if I hit a brick wall down the road.

As well, I decided very early on that I wanted to make removable baggage panels but had no idea what was involved. Yesterday I sent off an email to Van's just to get things on record for my build and to ask about #8 vs #6 screws if I did the removable baggage panels. But today I had to figure out process, configuration and counts. There is not a whole lot of information out there on how to do this but with enough research I see WireJock's RV7 page gives a good idea of what he's done. I will try to document my process a little better to answer all the questions I had. Basically I decided to follow wirejock's plan and use countersunk screws for everything aft (and including) the F-705 bulkhead. Everything forward of F-705 will be standard screws.

Modifying the F-716 seat ribs - 3 hours

It was a much bigger day than just 3 hours if you count set up and making the jig to drill the seat ribs.

I started the day by going to home depot to by materials to build a drilling rig for the drill press. Whenever I have holes I need to drill with odd parts or bits (like the 1-1/2" holes in the 716 ribs) I like to build a jig to properly secure everything. This gives a stable platform and the ability to clamp everything.


I then drew 1 1/2" reference circles on the parts as I will be initially drilling the holes to 1 3/8" and then opening them up to 1 1/2" (Better room for error this way).

I was then ready to drill four F-716 ribs.




Now I needed to cut the enlarged access hole. I drew reference lines first.



Then I made my initial cuts with aviation snips and then went to work with a file. Slowly but surely the material was taken away, and I worked up to the lines. Then I cleaned all edges with the small 3M wheel on the die grinder.

Little more riveting on the Aft Fuse - 3 hours

I haven't spent any time really on the build. Just soo unmotivated and I've been concentrating on getting back into cycling. In May I cycled 750 km (466 miles) so that ate up a lot of spare time in the evenings.

Fortunately my buddy Mike had some time to come over and give me a hand to buck some of the more tricky rivets on the aft fuse. By the end of the evening, nearly all of the corner rivets on the bulkheads were done. I just have about 10 to 15 left so I will schedule Mike for another night and hopefully we can finish it up.

Cut the F-916C spacers - 1.5 hours

Again, not feeling very motivated on the build. But I wanted to start in on the centre section and I needed to cut and drill the F-916C spacers. Its fairly straight forward, cut on the bandsaw, shape on the sanding station, then into the drill press.