Finished the top skin dimpling with the C-frame and clecoed the skins back on to the fuselage. I’m not going to rivet them for a while. I still need to do some wiring in the aft fuselage. That task will be much easier with the skins off.
I also worked a little more on the panel angle fabrication.
I did some deburring and dimpling on the aft top skin. I also did a little bit of shaping on some of the panel angles.
Last night was Adele’s piano recital, and I thought I wouldn’t get much done on the project tonight either. However, Adele’s swim meet was cancelled at the last minute due to thunderstorms. I was able to do a bunch of deburring and dimpling on the top skins. After I had enough of that, I started to look at what else needs to be finished up on the fuselage.
I was going to fabricate the push rod for the control columns, but it’s already made. Yeah! I just cleaned it up for priming once the weather improves.
I also looked at the plans for the area behind the panel. I cut a few parts to length that need to be fabricated.
I’m hoping to get the rest of the fuselage kit wrapped up by July 1.
In addition to some fun Father’s Day stuff (walking in the park, swimming, playing croquet), I spent a few hours deburring and countersinking the last few parts on the cabin frame. I just need to paint the parts and then rivet the support to the cabin frame and F-706 bulkhead. I might leave some of that riveting for later so that I can remove the cabin frame for better wiring access.
As I mentioned before, the blind countersunk rivets have a slightly larger head than the solid rivets. I didn’t countersink deep enough for that, so the heads were sticking up a tiny bit. I used the Scotch-brite wheel and some sand paper to take care of that minor problem.
I also did some dimpling and riveting at the top of the F-706 bulkhead. The plans have you leave out some rivets at the top of the bulkhead. However, with the new cabin frame attachment those rivets can be set.
I spent a little time today finishing up the cabin frame. I drilled the inside bracket holes, which ended up being rather difficult. I drilled #40 pilot holes in the brackets according to the dimensions on the plans. I then mounted the cabin frame, installed temporary bolts, and then used a drill bit to mark the hole locations on the frame through the bracket. Ideally, I would have just drilled the holes while the frame was attached, but there wasn’t nearly enough room to fit the angle drill through the access hole in the back of the frame. I disassembled everything and drilled the frame to #40 on the bench. I re-assembled the frame once again and then drilled the holes from the outside to #12 in steps. I also drilled the forward row of holes at the aft end of the cabin frame support.
I have a little bit of deburring, countersinking, and priming still to do, but the cabin frame is basically done at this point.
I drilled the cabin frame bracket and cabin frame through the skin. Next I peeled back the skin a bit and drilled the aft two holes on each side through the bracket and frame. Finally, I countersunk all 4 holes on both sides.
Progress has been sporadic lately. The school musical, soccer party and swim meets take priority over the project, as they should.
I found some time to work on mounting the cabin frame. I cut and then filed the ends of the cabin frame to wrap around the mounting brackets. At first, I thought Dan had read the plans wrong. But if you look at where the longeron is at, the cabin frame is supposed to almost touch the top of the longeron at the back. I rounded the bottom edges of the cabin frame quite a bit so it would nest inside the brackets.
I clamped the cabin frame to the fuselage with the brackets. Despite my efforts to the contrary, the cabin frame ended up being a little narrow after riveting. With 6 bolts holding it on each end, I think it will expand enough to work out fine.
I then turned my attention to the support brace between the F-706 bulkhead and the cabin frame. As part of the fix for the cabin frame service bulletin, Van’s shipped a whole new brace. This one is all nicely cut and pre-punched at one end. It’s just a matter of lining up the spacer I made previously with the F-706 and brace. You can drill out 4 of the holes to #30 from the top, but the other 4 require drilling up from the bottom. Only the aft row of holes is drilled to the skin and F-706. The F-706 gusset is in there as well, so this is one extremely sturdy connection. The forward row of holes at the aft end gets drilled only to the brace.
Before drilling everything, I verified the height of the cabin frame. The measurement on the plans of 17-7/8″ is from the top of the longerons to the top of the cabin frame. It’s a little difficult to measure this dimension. I placed a straight edge across the canopy decks, subtracted 1/16″ for the thickness of the decks and then measured from the straight edge to the top of the cabin frame. It was 1/16″ shy, so I added a spacer underneath the bottom of the cabin frame and re-clamped. It was dead-on after that.
I drilled the brace to the F-706 and cabin frame, including the small angle pieces on the sides of the brace (which aren’t mentioned in the instructions). That’s as far as I got for the night.
It’s been a busy week, but I found some time to work on the project tonight.
I found a good idea on Matthew’s site. I pulled out the top skin to verify the location of the cabin frame brackets. Once the cabin frame is installed, it should line up perfectly with the front edge of the skin. I drilled the brackets to the fuselage increasing from #40, #30, #21, #12, and finally 1/4″. I used clamps, clecos, and temporary bolts to hold the thing in place while drilling. It turned out pretty good.
With an AN4 bolt temporarily installed, I figured out how much needed to be trimmed off the outside edge of the bracket in order to be flush with the side of the fuselage. I put the bracket in the vise, and attacked it with the Vixen file. It took a while, but I finally got the brackets trimmed down on both sides.
I rented a Cessna this morning and did a couple of landings at Auburn. I figured it was good to at least land at the airport where I’m buying a hangar. Besides, Boeing Field where I rented the plane had the big runway closed for construction.
With the fuselage almost completely riveted at this point, I took a careful measurement of the fuselage width. Subtracting the thickness of the two angles that secure the cabin frame, the width was 42-7/32″. This is amazingly close to the dimension in the plans of 42-5/32″.
I started the day by priming a few parts, since I needed to prime the angle on the back of the cabin frame.
I started riveting together the cabin frame with the splice plates. (Don’t forget that angle!) I secured the front half of the cabin frame to a flat sheet of particle board and verified the width before starting to rivet the straps. I kept measuring the width several times during the riveting process, because Matthew had warned me that it can shrink. Everything was fine with just the splice plate riveted on. However, while riveting the straps in place the width slowly started to creep inward. I tried clamping it down, but that didn’t help. After I did all of the blind riveting to attach on the aft half, the width ended up being about 42-1/16″. That’s about 5/32″ more narrow that I need it, but I’m hoping it will spread out a bit when I install it. One tip on this part, countersink the holes for the blind rivets slightly deeper. They have a slightly larger head than the solid rivets.
After dinner, I messed around with the attachment angles a bit. I drilled and squeezed the keeper rivets. The plans are not real clear on where the angles should be located on the fuselage fore/aft, but it looks like they should be 7/32″ aft of the foward edge of the top of the 705 bulkhead. I was about to drill them, but decided to leave that major step until I look at it again with fresh eyes.
It feels like it was a very productive weekend. At least I got that crazy cabin frame riveted together!! That thing is a lot of parts and complication for something that is basically just a curved tube.
I finally riveted down most of the canopy deck. I’ve had it clecoed on for a few months, but thought I needed bucking help to rivet it. Most of it is easily squeezable. I had to remove the canopy deck yesterday to do the 705G riveting, and discovered that I had forgotten to countersink the longeron under the forward canopy deck. Doh! I took care of that and primed the countersinks.
I then tackled squeezing the canopy deck rivets. It went amazingly smooth. Looks awesome!
