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David Paule 12-02-2018 01:24 PM

Thanks for the comment. As it turns out, the RV-8 part that I used matches the part shown on Drawing 17, except that the rivets are on 1? spacing rather than 1 1/4? spacing per the drawing. And that increased rivet spacing is not detrimental. This part has 5/8? flanges just like the RV-8 part.

But here?s the left side of SK-40 showing the same part with a different description. This one shows 3/4? flanges.

This is typical of the RV-3B plans. There are a number of areas where the parts or assemblies are shown with different dimensions. I?ve found it handy to look at the RV-4 plans or the RV-8 plans for an idea of the design trend of Van?s, or just for some clarity. In this case, I?m using an RV-8 part. Looking at the RV-4 Drawing 23 indicates that a 3/4? angle is to be used on that plane.

Determining intent of the RV-3B plans is something like determining intent within the U.S. Constitution, but without the assistance of nine highly qualified justices, each approved by the Senate.

I?d have preferred a 3/4? flange for better edge distance,, if that were all there is to it, but that?s not the whole story.

If you look at RV-3B Drawing 25, there?s a panel edge detail that?s similar to the one on the RV-4. The RV-3 version is a strip of .032 x 1? that fits over this formed flange and over the edge of the panel itself. Although the actual detail of attaching it is not clear, there it is. It should provide more than sufficient edge distance for the screws.

The unresolved question is whether this strip gets riveted to the skin or the flange. I?ve heard it done both ways, with the general experience favoring riveting it to the flange, not the skin. That?s what I?ll do, glue and rivet it to the flange using the nut plate rivets.

I brought the forward turtledeck home since that?s the next skin to be fitted. It?s just resting here to give me an idea of the amount of material I have to work with. Unlike some of the other skins, Van?s was generous with this one. Plus its curve is close to about right.

And since I needed to locate the cheek bulkheads in order to figure out where to put the Mil-Spec cowling fastener mounting strips, I also brought home a Cheek Bulkhead Locating Fixture, which is more properly known as the top cowl. It?s way premature to be thinking cowling, isn?t it? But we had to place it in rough location to clamp the cheek bulkheads on. They seem to fit lower than I?d have expected. Here?s Mark Mantei holding the top cowl in place. With a bit of shifting left and right and a lot of pressing down on it, it sort of fits not too badly. Nothing that brute force and epoxy can?t ameliorate.

The photos are also hiding out here, here, here, here, and yes, here, too.


David Paule 12-16-2018 09:17 PM

With the engine mount still at my machinist friend?s house, I made the bulkheads straight and flat. For the firewall, I used a steel carpenter?s square (later changed to a larger one).

The square was attached to the firewall with magnets. The magnetic field goes right through the stainless steel firewall and grabs the steel square. The magnets are those small objects spaced irregularly.

The seat bulkhead and most of the remaining ones use cut-up scrap plywood. Fortunately, the project before this RV-3B was making new cabinets for my kitchen, so I had some plywood on hand. Here?s the seat bulkhead.

And here are the others. For the aft-most bulkhead, I merely clamped a couple strips of plywood to the bulkhead. This bulkhead is relatively small and this is sufficient.

I made a dirt-simple brace to support the instrument panel in the right position to line up the top front skin, shown here clecoed to the panel. I rotated the fuselage on its side to make access to the back of the panel easier. Even at that, I worked bent 90 degrees at the waist and twisted about 120 degrees. 19 years of yoga earned its way on that one.

Later I added the panel edge strip. This was distinctly out of sequence and ideally should have been done before I drilled the skin rather than afterwards.

This is the strip discussed in the posts above. On my plane, this will be riveted to the panel and used as a sealing strip back-up for the canopy fairing. The concept is easiest to see on this other RV-3B. I?ve labeled the pieces to make it easier to see how it works.

Perhaps the photos are also
and here, too.

Worth a try anyway, if the other photos have gone belly up.


ppilotmike 12-18-2018 10:57 AM

Looking GOOD, Dave..
..I'm impressed with your progress and enjoy reading your posts.

David Paule 01-03-2019 07:43 PM

The front top skin is drilled to the panel. Only the aft edge is clecoed so far. The firewall edge is held with cleco side clamps.

As you might have noticed, I placed my instrument panel vertically. Doesn?t match the plans and probably not my brightest move, but with the top skin roughly trimmed and drilled to the panel, there it is. I confess that the verticalness is an error. Like every single change that can possibly be made to a kit airplane, this one had a ramification. The F-320A strip that goes between the F-320 forward top skin and the panel is shown in the plans to be straight. Since my panel is vertical and that skin slopes forward, my F-320A strip can?t be vertical. I determined this the hard way.

Here is an excerpt from drawing 25 for this, showing both the slope of the panel and the straightness of the strip.

Here are both strips that I made. The later inner one is the one shaped to fit. It?s a somewhat conical shape but of course that varies over its length. The shape was determined from the F-320 top skin, which is trimmed to fit the panel (and drilled to it, which is why I haven?t adjusted the slope of the panel).

The top skin, incidentally, has excess length. Wish the bottom tailcone skin did, see post #318. There was plenty of material to make both the ?incorrect? first and the made-to-fit second strip.

Incidentally, the plans say that the strip is riveted to the top skin. Mine will be riveted to the panel?s edge angle and flush with the face of the panel. I know of at least one other RV-3B with the strip attached to the panel.

The top skin?s curve isn?t bad at all. But typical of the external skins on the fuselage, the curve needs to be adjusted somewhat, in this case over the longerons. I?ve heard of at least one RV-3B where this skin is made flush to the side skin by using a curved angle doubler, with one leg on the top skin and the other riveted to the upper longeron. I?m choosing to overlap the top skin on the side skins per the plans for this one. It?s a thicker skin than the aft belly skins and so far, let?s just say that I?m working on it.

After several attempts at bending the top forward skin so that it fits better to the longerons, I brought it into the kitchen. The counter there has a 1/4? radius, which seemed perfect, knowing that there would be spring back. I clamped it to the counter and used that length of 2x4 to press against it. It took most of my weight, augmented by a foot under the bar rail and another against the pantry, not shown, to do the job but now it fits well. You can see the result at the bottom of the photo where teh opposite side to the clamped one is already bent.

The photos are hosted in an alternate location if the primary location goes down:

Here's one,

and the next,


and the last one.


rockwoodrv9 01-03-2019 09:42 PM

Looking good Dave.

David Paule 01-20-2019 10:31 AM

Russell sent me a photo of Larry DeCamp's plane, showing how he’s attaching the forward top skin to the sides. He’s installed an angle, riveted to the top longeron, for the top skin to attach to. I understand this is how the Rocket does it. He could have done much the same thing by insetting a strip partly in between the skin and the top longeron. As I mentioned, I’m overlapping the sides per the plans, and am not using an attachment strip or angle. Here’s Larry’s method.

That strip that goes around the panel got glued to the panel’s flange, as much so that I don’t have to keep checking and unclecoing it every time the skin is on or off. Here it is with the glue curing and the tape off.

I used my Whitney Roper punch to put cleco holes in the top firewall flange for the top skin’s screws, and drilled the top longerons and side skin for the top skin holes. I rotated the fuselage to make it easier to back drill those holes and when the skin was strapped into position, did that and the firewall flange. All the screw holes are pilot-drilled into the top skin now.

With most of the various holes drilled, I riveted on the nutplates and dimpled the holes in the skin. So far, with the firewall still undimpled and no nutplates, the skin seems to fit.

Then since I’d located where I thought the rudder cables should exit the fuselage, it seemed like a grand time to make that slot and work on something else for a bit. A while ago, I found the location using a tight string and measured ends, and I drilled the bushing holes in all the bulkheads. At this point, the left rudder pedal is clecoed in place, with the length definitely TBD, so I clamped a string to that, ran it though the holes and then….

And then I got the vertical stabilizer down from the rafters, made a few measurements and markings, did the same for the rudder, and then but those back up there. I compared my marks and bushing holes to the plans dimensions on drawing 26 and added those marks too. Reassuringly, they were close. I checked the winds aloft, the latest political polls and pilot-drilled the end holes for the slot.

Funny how the plans offers zero guidance for the width of the slot. But an RV-4 builder suggested 3/8” and since that’s the diameter of the plastic sleeve over the cables, that seemed just fine. Remember, the cable exit cover will hide the slot. Here are the end holes on one side.

Using a Dremel cut-off disk, I made these into slots.

I was thinking about making the short steel links that connect the rudder cables to the rudder pedals, but soon decided to postpone that until things are further along and maybe I can sit in it. That’ll help set the length of the parts.

A while ago, I’d installed the static ports. I’m using Van’s blind rivets per the plans. I’ve observed that people who use other brands static ports often have relatively poor static pressure performance, and that makes sense. They are shaped slightly differently. Van’s flight tests their own product and recommends a placement based on that. This being important, I’m using Van’s.

As is my practice, the photos are also hosted elsewhere.

here's the first, and the second, the third, fourth, fifth, and final one.


David Paule 01-28-2019 12:06 PM

Pattern Time
The strip for the Mil-Spec quarter-turn fasteners for the top of the cowling now has a pattern, not shown. I had a bit of aluminum for that, but it?s one inch too narrow, since I need to allow for the semi-conical shape of the thing. New piece on order.

Next, I figured that this was a good time to make a pattern for the baggage floor. The piece of aluminum supplied with the kit has a curious shape, and the cut-outs for the flap torque tube arms looked large to me. That plus Ironflight?s comment about needing to make a pattern for his, all combined to say make a pattern. Don?t just start cutting.

And a good thing I listened, too. I found some white poster board at the hardware store and dove in. Immediately, it was apparent that there was no way it would fit into the baggage compartment as a single piece of card stock. I cut it in half. It was then difficult to put each piece in by itself, but eventually, I got both sides trimmed. And more card stock taped on, and trimmed again. Kind of fun, working that way, but then elementary school subjects sometimes are.

When I finally got both pieces in together, and taped back together, the difficulty of putting the pattern in or removing it returned. And what about the final skin?

I temporarily installed the flap torque arm assembly and marked, generously, lines around the arms. After removing that frame and the pattern, I then laid out the cut-out from the plans. You know, it?s a better fit than I?d thought. But a tweak here and another there, and I was able to refine the cut-out somewhat. And, remember this, it was now easy to get the pattern in and out. While it might be wishful thinking, maybe the baggage floor will go in readily, too.

Here?s a pic of the pattern in place, but not the flap actuator tube. At the bottom cut-out, you can just see the plans version of the cut-out at the aft end of the hole. Yes, there's plenty of room for working at the pushrod.

I?ll probably do some additional minor trimming before I cut metal.

On the far right, you can see that the halves of the bulkhead top are unconnected. The splice plate is under that bit of blue tape. That'll be part of the aft tailcone skin project, by and by.

And here's the back-up photo link.


David Paule 02-17-2019 07:43 PM

The RV-3B has a depression in the seat pan to accommodate a large pilot, which I?m not. Typically, the builder adds foam to fill the shape. I?ve heard that some of the seat cushions get pretty heavy.

So I?m making a wee change in the seat structure. This picture shows both the existing ribs and one of the added webs. The fuselage is on it?s side here, in case you?re wondering why the photo is odd.

I made some flanges and epoxied them to the webs. Here they are curing on the table. Later, I riveted the flanges and the webs together, using -4 rivets.

With the parts clecoed in place,

RV-6 owner Rick Brennan was willing to try repairing my landing gear screw-up. Two commercial machinists were not and another one was willing, but didn?t give me a sense that I?d have flyable parts afterwards. Rick not only had a sensible plan for the tapered pin, he set it up so that we'd have a Plan B if we had trouble with the primary scheme.

Here?s the engine mount and gear leg clamped in the custom fixtures ready for attack. Since then, progress has been made: the tapered hole is within .004" diameter of being ready for assembly. The final bit will need another reamer, now on hand. And with the first plan so close, we developed a follow-on Plan C if we still couldn't do it.

I have had nothing but trouble drilling holes for tapered pins on this RV-3B.

If these photos should ever disappear, try this alternate place:

Here, here, here, and finally, here.


FinnFlyer 02-18-2019 08:36 AM

2" thick white styrofoam is not heavy.

For my RV-3 I got a 4x8' sheet from Home Depot and cut it with a hot wire.
Also did that to fill in the back seat.

If you're ever going to sell it to a tall pilot...


David Paule 02-18-2019 12:34 PM

I suppose the future will have to figure that one out for itself, Finn, it's not on my list of things to worry about.

The rudder pedals are ground-adjustable and the cushions will be too. If I haven't sold it separately beforehand, a Todd's tall man's canopy can be included. Other than that, a tall person will have to see it and decide. Someday.


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