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-   -   RV-3B Dave's in Colorado (https://vansairforce.net/community/showthread.php?t=85658)

David Paule 11-29-2020 08:09 PM

Here's the final version of the hold-open latch. I still need to trim one leg of the bracket where it touches on the shoulder harness slot. I clecoed the canopy on just to get a feel for it with that, plus notice that bit of blue tape? To see if that touched the canopy. It didn't. In the open position:



And in the closed position, this time with the canopy removed.



Here, the latch arm doesn't interfere with the canopy. It did with the prior version. As it is right now, it works quite nicely, latching by itself when the canopy is opened, and by lifting the latch arm, the canopy is free to close.

The biggest changes as this evolved were the brackets that go on the seat bulkhead. Here is the evolution, from #1 through #3. Number 4 is the current version. Each tweak got me closer, although with #3, the poor canopy would touch the latch arm, so I had to tweak it one more time.



Dave

RussellT 11-29-2020 08:25 PM

Looks good Dave, time consuming but ultimately satisfying.

Regards, Russell

yarddart 11-30-2020 10:12 PM

Looks great I have robs Rv3b love the gas shock

PaulvS 12-02-2020 10:43 PM

Final latch
 
Dave, Mk III of the canopy latch looks good, I like how you managed to have the arm out of the way when the canopy is closed.
Perseverance paid off.
We of the older kits are BUILDER men! ;)

David Paule 12-12-2020 06:32 PM

The main latch bars are now drilled through the frame to the fuselage. Since these photos were taken, I bonded brass bushings in to the frame, but that’s still in progress.

Here’s the latch shown open (the cam is not installed at this time):



Here the latch handle is half-way:



And here it is in the closed and latched positioned. These photos show that the latch bars do not slide axially, but because of the latch handle rotation, have a small rotation coupled to the axial motion. It's not much.



If you don’t remember the avionics shelf, go back to post #473 for a quick review. I removed the forward coaming, the cover forward of the panel, and trial-fit the avionics shelf to the fuselage. Here it is roughly in place.



Its aft face will become the switch panel. Here’s a view from the cockpit showing that face.



The shelf had been resting in a pile of parts. Being fiberglass, and this being a fiberglass phase of the project, it seemed appropriate to do a bit of work on it.

Dave

David Paule 01-10-2021 06:03 PM

Here’s the avionics shelf with the goodies resting on it. I think there’s room to run the wiring around but that’ll have to await actual placement.



At this point, all three canopy latches all work as they should. That took more time than I’d expected. But they work now.

Since then I’ve been filling and sanding the canopy frame/fairing assembly. You know (or will know) the routine:
Fill, sand, paint, repeat. Over and over again.

In this sequence, there was a lot of time where I’d be waiting for something to dry. One thing that needed doing eventually is the manual flap handle latch system. Most of its interior parts are complete but unassembled; the latch or quadrant attachment has not been started. Here’s an overview of the system from drawing 30.



Note 2: See these AN3 bolts? That’s because the latch hangs off of the seat rail, and the downward force is carried in what stress analysts call “heel and toe action,” with the bolt in tension. The quadrant must rest solidly on the seat pan - this was verified. It’s not a robust design and in any event, it interferes with my flat seat, which has #8 screws all along that angle.

Here’s what it looks like looking aft, also from drawing 30.



Note 1: With a downward force on the quadrant, those poor bolts need to transfer all the bending into the angle. The drawing shows the quadrant resting on the seat pan. Remember that my seat pan rests flat on that angle. I was pretty sure that I couldn’t get #10 nutplates in there if I wanted to. So I installed one more #8 nut plane and looked for ways to eliminate the bending around the rail.

After rejecting things like struts underneath, I settled on a beam to the seat rib next inboard. But since I’d need to cut away the seat pan to clear the mounting angle for the quadrant, that 2 x 1 1/2 x 1/8 angle, I needed to support the free edges of the seat around the hole. This shows the beam in place.



Getting back to the canopy fairing, it looked like today was a good day to spray it because the humidity was up. Stewart Systems EcoPoxy, water-based, needs a somewhat humid environment. Since my usual table outside had four inches of fresh snow on it, I painted it in the shop. EcoPoxy dries to the touch quickly enough that I could get a photo before I lost daylight.



The timing was a bit of a jiggle because I was rising, proofing and baking a loaf of sourdough bacon bread simultaneously.



Compared to an airplane, bread is instant gratification.

Dave

Ironflight 01-10-2021 07:53 PM

David - is that tall battery really going to fit all the way over there on the edge? Just checking.....

Your task on the avionics shelf layout is very familiar - I had to do the same thing on the Subsonex, as there was no guidance on where things should go, and the tapering glareshield (not applicable in the -3, of course) made for an interesting set of compromises.

David Paule 01-10-2021 08:57 PM

Paul, good eye. A quick double check shows that it will probably need to be moved. My initial check had indicated that it would fit. Tonight's check was fairly cursory but it suggested the opposite. If necessary, I'll rearrange things, of course, and probably shuffle the contactors and ANL holders with the battery.

What I'm concerned with are the wire runs. Ideally, I'd like to arrange them so that they wouldn't impede removal of a device. That'll be a fun exercise when I get that far.

Dave

Dan 57 01-11-2021 02:50 PM

Thanks for your blog Dave, interesting, well written with a good choice of pictures :cool:

Interesting to read how you encountered the same problems (ex. bulkhead flanges, etc, etc), plan inaccuracies, and more. Same as hundreds of -4 and -6 builders resolved with some head scratching before social medias or the internet. Brings back some sweet memories...
Built 3 VS on my -4, ordering from North Plains by fax, overseas money transfer and astronomical shipping charges, all fun in good ol’ times.

Some of your problem solving is, well, let’s say interesting, but on the whole a very good quality build, well done, looking forward to more.

Ironflight 01-11-2021 03:26 PM

Quote:

Originally Posted by David Paule (Post 1493108)
Paul, good eye. A quick double check shows that it will probably need to be moved. My initial check had indicated that it would fit. Tonight's check was fairly cursory but it suggested the opposite. If necessary, I'll rearrange things, of course, and probably shuffle the contactors and ANL holders with the battery.

What I'm concerned with are the wire runs. Ideally, I'd like to arrange them so that they wouldn't impede removal of a device. That'll be a fun exercise when I get that far.

Dave

I am sure I shuffled stuff around on the Subsonex tray a couple of dozen times, each time thinking I had the “final, best” layout until I thought of some other reason it wouldn’t work (wiring runs being once of them). Also, I am sure you’re going to do this - Nutplates for all mounting screws so that out is easy to R&R components when required!

Paul


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