More fun fitting the canopy frame

More fun with the canopy this week as I spent several hours adjusting the fit of these parts that form the rear canopy frame.

The distortion caused by both the flanges and L-shaped bend in each frame half takes some work to make them fit adequately. The instructions tell builders to flute these parts to remove the distortion, but at least one of mine was just about right out of the box and really didn’t need fluting. The other one doesn’t fit quite as well, but I’m resisting the urge to flute it because (a) the fit isn’t that bad and (b) I tried fluting a spare frame part I had and it was a PITA.

In this picture the frame halves are not perfect, but they’re getting close to being good enough.

Rear canopy frame

The side rails were an easier fit, because Van’s had already done all the bending and metal shrinking needed to make the side rail curve fit the longeron bends I worked so hard to perfect several years ago.

Canopy side rails

The side rail flanges don’t quite conform to the aft frame parts, but I think they’ll pull into shape pretty well when they’re drilled and clecoed.

Side rail to canopy bow fitI still have some parts to fit to the frame, so stand by for more words and pictures.

Canopy splice platesLaying out the side rail and rear canopy bow splice plates. Note that the side rail doublers at the bottom have one hole that isn’t marked to be drilled – that’s because Van’s conveniently forgot to mention in their plans that there’s already a hole through the canopy frame in this area, and if you drill the hole in the splice plate it won’t line up with the frame hole.

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Ok, so I said I wasn’t going to flute the rear frame – but I did, and it actually came out pretty well. Here’s the side rails and rear frame clamped into position.

Fitting the side rails

The little cheapo Harbor Freight clamps are holding on some strips of 0.032″ scrap that simulate the canopy side skins. The side rail is correctly placed when the bits of scrap lie flush with the side of the fuselage.

Side rails drilled to F-631s

Sharp-eyed RV builders will see that I’ve inserted a shim between the side rail welded angle and the F-631 rear frame half.  The fit wasn’t quite what I wanted, so when in doubt – shim it out. After that I couldn’t think of a good reason not to drill everything, so I did.

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These plates splice the side rails to the forward canopy frame, and drilling them was a bit of a pain. It’s vital to uncleco and peel back the forward canopy skin, as nine of the ten holes in this part don’t go through that skin and drilling through it would be uncool.  You’ll see one hole (bottom row, second from the right) that doesn’t quite line up. That hole *does* go through the skin and frame, and once the other holes were done I back-drilled this one using the forward frame as a guide.

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And here’s everything drilled and clamped to make an almost-complete canopy frame. As my friend Jim would say, this is one of those moments of Big Visual Progress. They kinda sneak up on you after a lot of tedious fitting and drilling, then suddenly everything comes together…et voilà, it looks like a real airplane part.

I hated to take everything apart, but there are a couple of small parts left to fabricate and fit to the frame.


Look carefully in the pic above, just under the two leftmost copper clecoes, and you’ll see a thin aluminum wedge filling the gap between the side rail splice plate and forward canopy frame flange. Scroll back a couple of pictures and you’ll see the unfilled gap.

I had to make two of those – one on each side of the canopy – and each one took about an hour of cutting, sanding, filing and fitting.  What fun…but now I can take the frame apart  and debur, countersink and prime everything before riveting. And that, in turn, means it’ll soon be time to work on the plexiglass canopy itself.

A week of airplane building

A solid week of airplane building…missing Oshkosh, but getting a lot of work done.

I’ll be adding text here when I get the chance.  Right now it’s a holding place for pictures so I can document what I got done…more to follow.

Support for brake line Adel clamps

Matco PVPV-D parking brake and doubler –

Parking brake valve and doubler

Doubler plate taped to firewall

Temp fitting the parking brake doubler

Testing out my plumbing idea.

Valve taped into place

Parking brake taped into place to check lines

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Parking brake valve crossover lines installed.

Brake lines protectedBrake lines protected against abrasion with spiral wrap. Somehow it makes them look more “finished.”

Canopy latch parts painted

Canopy latch parts painted

Canopy latch installed

Massaged the canopy frame, then reinstalled skin. Flush dies in the pneumatic rivet squeezer helped work out inadvertent creases in the skin, and a flush set in the rivet gun helped with the frame.

Canopy taped for final drillingCanopy taped in place with spacers installed for final fame drilling.

Riveting the canopy frame 1

Riveting the canopy frame. It’s about time I put that 12″ double-offset back rivet set to good use.  It sucks up a lot of kinetic energy, though…90 PSI on the compressor just to get the rivets to set.

Riveting the canopy frame 2

Another picture of riveting the canopy frame

Frame riveted

Here’s the canopy frame riveted, with the skin reinstalled, and fitted back into place on the fuselage.

Canopy frame fitted and ready for drilling

Final fit before drilling the hinge brackets

Canopy frame side fit

Fit is pretty good on the right side.

Hinge hooks drilled, bushings insertedCanopy hinges drilled and bushings installed


Framing the canopy

Today we started the last major structural part of the airplane – the canopy. The canopy is constructed from the forward edge back, and the first step is to fit the forward canopy skin to the welded aluminum canopy frame.

The frame has some holes already match-drilled in its forward ribs so it’s not tough to get the skin on the front of the frame, but the aft part of the frame is drilled in assembly with prepunched holes in the skin. The aft frame tube didn’t line up particularly well with the skin, so I had to apply some manual persuasion (i.e., I used a dead-blow hangar) to make the tube align with the skin for match-drilling.

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I drilled the holes to #40, although they’ll be drilled later on to #30 and countersunk to accommodate blind flush rivets.

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The skin still doesn’t fit particularly well…there are some gaps between the frame and skin that just can’t be closed. From reading various online forums and other builders’ websites, this is a common problem and I’ll find a way to deal with it.

2014-11-11 11.47.45Also, the canopy frame sides don’t line up well with the fuselage. Some additional manual persuasion may be required here…

Latches and linkages

Next up on the canopy task list…installing the side latch handle, linkage and latch tube. The only tedious part of this process was laying out and cutting holes – very visible holes – in the fuselage side skin to accommodate the latch handle slot and rivets.

Vans includes a template in the plans to lay out and drill the holes, but I decided to measure and lay them out by hand.  It took a little time, but the results were good.

Laying out latch holes

The four larger holes in the middle mark the start and end of two rectangular holes for the canopy latch handle. I used – very carefully – a cutoff wheel in my Dremel tool to start the holes, then finished them with a flat jeweler’s file.

Opening up latch holes

I borrowed an idea from fellow builder Mike Bullock and clamped a piece of scrap angle to the skin as a reference for filing. The holes came out nice and straight…very cool.

Latch assrmbled

Here’s the latch mechanism itself – two pieces of 0.063″ angle sandwiching the latch handle (top) and locking mechanism (bottom).

Drilling the latch

The latch mechanism fit almost perfectly in the slots I cut – only a little adjusting was required on the front hole. I clamped the mechanism in place and match-drilled the angles to lock the whole assembly into place.

Latch clecoed

Here’s the other side with the spiffy yellow latch knob installed. There’s also a very small hole drilled in the wing carrythrough bulkhead which supports a small spring that keeps the locking mechanism pressed against the latch handle.

Fitting latch tube

The latch tube itself is held in place by two Delrin blocks that are match-drilled to the F-705 bulkhead. Fingers on the latch tube engage holes in the bulkhead. There was only one minor problem – the tube was slightly too long, which made it impossible to center the blocks on the F-705 reference holes. A tubing cutter took care of that problem.

Latch tube drilled

I drilled the blocks to #10, and the F-705 holes to #12, to accommodate AN3 bolts that hold the blocks to the bulkhead. Here’s the tube bolted into place, and two parts of the latch linkage in place.

Latch linkage fitted

The only remaining part to be fabricated was the pushrod that connects the latch handle to the latch tube linkage. Nothing too difficult, just a lot of twisting with a 1/4″-28 tap.

Latch linkage with tube

And here’s the final product…everything works smoothly.  Cool.

Starting the canopy

Although I still have to finish up the elevator pushrods and mount the horizontal and vertical stabilizers, I’m moving on to the canopy frame while I decide what to do about Van’s horizontal stabilizer service bulletin. I haven’t decided yet whether to mod my horizontal stabilizer per the bulletin, or just build a new one…

First steps on the canopy are fabricating the alumunum and Delrin spacers that accommodate the canopy hinges.  Nothing too complicated here…

Canopy hinge spacers

Fitting them to the forward subpanel was slightly tricky, since Vans tells you to predrill holes in the spacers that they tell you later to match-drill in place with the subpanel. Fortunately, the hole locations called out in the plans are spot on, so I didn’t have much trouble fitting the spacers.

I didn’t take any pictures of the fitting process, but here’s the finished product on the left side…

Left hinge spacers…and on the right side.

Right hinge spacers


On the gear

As my friend Jim might say, today was a day of great visual progress. The only remaining task to get the fuse ready for moving was to get the wheels mounted on the gear axles, then the airplane would be ready to sit on its gear and roll out of the garage for a photo op.

That required some relatively-messy wheel bearing packing. Fortunately I remembered a bit about greasing wheel bearings from our days owning the Mighty Archer, and after a few pairs of rubber gloves and some liberal application of Mobilgrease 28, the bearings were packed and the wheels installed.

Business end forward

Looks great, don’t you think?

A long time coming

Another picture? Sure, I knew you’d want one…

2014-04-19 16.08.17This was the first opportunity to use the N701ED wheel chocks that Ellen gave me a few years ago…they look nice!