What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

RV-3B Dave's in Colorado

I've been making ailerons. And here's a couple of tips:

1. Drill and rivet the counterbalance to the nose ribs BEFORE riveting the nose ribs to the spar.

2. Drill and dimple and rivet the stiffeners to the skin BEFORE tightening up the trailing edge bend.

Here are the frames - the spar and ribs riveted, with the counterbalances trimmed but not drilled, not riveted or for that matter, not even primed.

tmanLfu.png


The observant reader will notice that I haven't drilled the holes on the bottom of the spar yet.

The lightening holes in the spar were drilled using a hole saw from which I'd removed the pilot drill, replacing it with a round bar. This went into pilot holes previously drilled in the spar web and into a backup wood block that had a lubricated pilot hole and was clamped to the table. That gave me nice clean holes.

Dave
 
Last edited:
I've ordered shorter screws than the AN509-8R8 that Van's supplied for the tanks. The AN509-8R8 are too long and that

a) Wears out the nutplates faster than necessary,

b) Sticks into the wing too far, snagging cables and things,

c) Weighs more than necessary.

I ordered MS24694S3.

The aileron counterbalance pipes are primed. I sprayed a bunch of zinc chromate into them and verified that I got full coverage. I riveted them to the nose ribs using AN470AD4-6 solid rivets. The photo will show how I obtained clearance. There simply wasn't room to get a blind rivet tool in there. Refer to point #1 in the post above. I was able to use my squeezer with a 3/8" diameter set. This set is too small diameter for routine work but was perfect for this.

e3CUzz3.png


As you can see, I've got to touch up the ends of the pipe a bit with a drop more zinc chromate.

I primed the stiffeners and have cleaned the aileron skin but not primed them yet.

Dave
 
Last edited:
Aileron Leading Edges Dimpled

This wasn't hard. First I countersunk and primed the holes in the leading edge pipes.

q5rpccU.png


Then I put a male dimple die on one of my yokes and got my trusty 2 lb. ball peen hammer out. Sure looks like I'm prepared to bash the heck out of it doesn't it? But actually using a heavy hammer makes the job easy, since the speed of the impact can be low and still generate sufficient kinetic energy to develop the required strain energy to form the dimple.

MDWFj7y.png


And here's a sample of the final dimples. All done with that now.

EkyPzg2.png


The ailerons are all dimpled but I still need to trim the leading edges at the inboard and outboard ends.

Dave
 
Last edited:
Looking good Dave. The pipe you are using looks much different than the one in my wings. Is it galvanized?
 
Top Aileron Spar Flanges Riveted

I made a pair of stands to support the aileron. The bottom block prevents the aileron from flopping over, since it's top-heavy. I tried to use the bending brake as a stand as Larry had described in Kitplanes but was unsuccessful with mine, hence these stands.

LBnYV8m.png


I added the horizontal wooden batten for a rivet set rest and that helped a lot.

Mie1zCE.png


An "L" shaped bucking bar proved the most practical, but in a few places near the flanges the tungsten bar could be made to work.

These rivets on the top flange of the spars, are now complete.

cenwSPN.png


I'm using an under-cabinet light as a shop light. It fit into the aileron and made it easy to see the rivets with an inspection mirror. I checked nearly every one.

Dave
 
Last edited:
Ailerons Riveted

I had to add some shims to the forward ribs on the top flanges, which was annoying, but still finished riveting the ailerons.

The flap stiffeners are trimmed but not finished.

I've started the airfoil jig to locate the aileron hinge parts to the wing. Since this airplane is not pre-punched, everything needs to be located in space. The jig fits over the wing and has location features associated with it. Hinge location dimensions are with the aileron drawing, the jig is shown in SK-30.

If you're building one of the more advanced kits, the SK drawings are more sketch-like, more informal, than the bigger ones. They're in the manual, not the plans set. They usually describe things like skin dimensions or jig arrangements and given the paucity of information in the plans, are essential parts of the process.

Sorry, no photos at this time.

Dave
 
Figured that this would be a good time to see how well the ailerons fit the wing. It's a good time because I haven't started the flaps yet, except for roughing out the stiffeners, and some builders have reported that the flap trailing edge extends aft of where the aileron trailing edge would like to be, without some massaging to make them line up.

I plotted out the dimensions from Dwg 4 on a slab of nice plywood to make the wing template cut-out. The manual says that a paper template is provided, and if it's not, then the outline is drawn on the lid of the wing kit. Of course, neither were supplied with the kit. I got to use a spline and ducks, or I would have if I'd had any ducks. But I didn't. Ducks, in case you didn't know, are real tools. Well, yeah, they're also birds. Here's an article about making your own. Me, I just spotted some weights around and they did the trick. I drew the actual airfoil curve and an outline 1/4 inch fatter than that all around, to allow for carpet.

Since this is an RV-3B and the builder MUST be suspicious, I went and bought a piece of posterboard and made an outline of the actual wing. I used the left tip and cross-checked it to the right tip. Here are the nose and main sections of the posterboard template. If you look closely you can see that they don't match the drawn lines at all.

YgYYnBD.png


Also they don't have centerlines.

I used the tooling holes in the wing ribs to determine the centerline positions. Should have done this before I assembled the wing!

Once I got things lined up and checked it didn't look all that bad.

Here's a picture from the plans showing how the fit is supposed to be. The aileron spar should be 3.75 inches aft of the wing's rear spar, and the aileron, trailing edge to spar, should be 9.25 inches - and that's okay.

xlSrdzI.png


I drew out a template on the posterboard for the aileron and it matches the actual ailerons nicely. Unfortunately there's an issue: The wing skins are too far apart for the aileron to fair properly. Look closely at this picture:

P3JYteE.png


The aileron spar is located the proper distance aft of the wing's rear spar. The aileron and wing centerlines are lined up. The aileron trailing edge is .40 inches aft of where it should be, but that's not a serious issue. Look at the top skin (The wing section is shown upside down so it's on the bottom) and the bottom skin (shown on top). They sure don't line up with the aileron, do they?

There's the problem.

Dave
 
Last edited:
Dave,
I'm not sure if this might help you, recently I read something in the "27 vears of the rv-ator" regarding a similar problem with ailerons which do not line up perfectly with the trailing edge of the main wing skin; see page 122 of the PDF version in the wing section.

WING SKINNING
Check Those Flange Angles [2/93]
by Van
Several reports of .....


Peter
 
Peter, that was a very good comment, thanks! When I got home tonight, I checked this, and my wings have this issue to some extent. It looks like it might get me part-way there.

At any rate, it's something I'd better do. It'll help.

Thanks!
Dave
 
Dave,
I'm glad that the hint was helpful.
Furthemore, I 'm very grateful for your thoroughly descriptions of your building process. For me it's always great to see some pictures, how the things go together.

Thank you,
Peter
 
Peter, that really was a very helpful comment. I'm now making a wing cut-out shape, shown in SK-30, that I wouldn't have started without that help. The glue is drying on the carpet padding right at the moment.

Thanks very much.

Incidentally, for anyone planning on building an RV-3B, find about a square yard of industrial carpet, something relatively thin and stiff. It makes great edging for the various jigs that you'll be building. I just use ordinary white glue to hold the carpet to the plywood, and blue tape to secure it while it cures.

I keep a cost log for this project, and one of the major headings is "Infrastructure." That includes things like blue tape, glue, pencils, vacuum cleaner bags and so on. Things like plywood for the forms go into a separate heading called "Jigs and Tooling," not to be confused with "Tools," another one. The "Jigs and Tooling" is used sufficiently often to justify a heading of its own. It's surprising how much wood is used to build this all metal airplane.

Here's the current contour shape for the aileron-wing area. I've asked Van's Support if this is okay. The hinge is in the correct position, the aileron's chord line is on the wing's chord line, the top skin (now adjusted thanks to Peter's tip) fairs to the aileron, but the bottom wing edge is below fair by about .11 inches (2.8 mm). This time, the photo is right-side up. If you look close, you can see that I've drawn the rear spar and doubler on a bit of Mylar drafing film, and placed it on the posterboard.

D0v3CW0.png


Dave
 
Last edited:
Mike, take a look at post #160, where Peter suggested the "27 Years of the RVator) and referenced a particular article. Basically, it was about re-forming the aft contour of the top surface if it wasn't proper.

I had to make the tool described there (simple) and a pattern and then it just took a little time.

Dave
 
I'm working on the aileron hinges. Some of the very few pre-punched parts in the RV-3B kit include these hinge pieces. While having the small holes drilled is nice, the important thing is that the big ones are, too. And the really important thing is that they are bored for the bearings.

Unfortunately not all bores are equal. I had four bearings and eight aluminum pieces and a little more than half the bores had a slightly oversize diameter. The bearings (all of them) could shift radially slightly, perhaps .010 inches. I didn't bother measuring it.

What I did do, was clean the bores well and using a toothpick, smear just a little JB Weld on the circumference of the bores for the loose ones.

cAlbY9v.png


I used JB Weld simply because I didn't have any 3M 2216, which would have been the preferred adhesive. Another suitable adhesive would have been some Lord 320/322 adhesive, but I didn't have any of that, either. Still, this being only a shim, it's not critical.

After assembly and curing, I verified that all the spherical inserts in the bearings were free.

Dave
 
Last edited:
A Slight Detour

I decided that the left aileron really wasn't very well built, and am building a replacement. The original will go into the Attic of Embarrassment along with the other parts that I've replaced.

This time, I'm installing the stiffeners before bending the trailing edge. Although the factory bend is tighter than I'd remembered, it's going smoothly so far.

Here, I've got the matched-hole tool inside the skin drilling the holes for the stiffener rivets. I used the same tool to drill the holes in the stiffener, and gotta say, thanks, gasman (see post #144) for the suggestion. The stiffeners fit better this time around.

N4ypoZH.png


Note that I added an arrow to the tool, to help me ensure that the forward end really was forward. Colored tape works great for that sort of thing.

At the moment, I've removed the vinyl and am ready for deburring and dimpling the skin. The top flange of the spar has its rivet holes drilled to the skin. The spar reinforcement plates are on and the lightening holes made, and the spar and stiffeners are primed.

Interestingly, the spar was straight right out of the box. Drilling the lightening holes let it relax and now it's got a bend to it. Fortunately it's flexible enough that this is of no consequence, just that it was fun to watch develop as I put in the lightening holes.

Dave
 
Last edited:
1/2" Galvanized Pipe - Poor Finish

I bought one from Van's with the rest of the parts that I ordered for my third aileron. The pipe came from Van's with a terrible finish. It looks more like a coating of ash than galvanized. Support said to scrub it with Scotchbrite and then prime it.

I went to Home Depot and their pipe is metal-stamped with the country of origin and some other information. The stamping is sharp-edged indentation.

So I went to Lowe's and there I found a good pipe, nothing unusable at all about it. Good galvanized finish, no damage from stamping it. All three pipes have the same specs.

I weighed all three pipes and, adjusted for length (Van's was longer; they all need trimming) and allowing for the threads on the HD and Lowe's pipes, all three weigh within just a few grams of each other.

I'm going to use the Lowe's pipe.

The stiffeners are riveted on, the ribs are drilled to the spar, and the spar to the skin on top.

Dave

Dave
 
Cracked Nose Rib

I'd drilled the nose ribs and while deburring them, discovered that one of them, A-303-R, was cracked. I've contacted Van's for a replacement.

The crack is on the flange that attaches to the pipe (and yes, I didn't stop the drill in time....):

TRM1ofy.png


It extends roughly halfway from the edge to the tooling hole.

So in the meantime, I'm working on the flaps.

An odd thing happened yesterday. I live in a college town and sometimes strangeness ensues. Three young men showed up at my front door with a rusty tailpipe and muffler. They explained that they were competing to scrounge the oddest and largest bit of mechanical junk - could I help out? They'd trade that tailpipe for anything better. I invited them into the shop and gave them the poorly-built original left aileron. They didn't know what an aileron is. I showed them pictures and explained how the controls worked and they were happy. They took the tailpipe with them.

Now I've really got to finish this new one!

Dave
 
Last edited:
Flaps. The stiffeners are made and drilled. I'm using the same sort of drill jig I used for the ailerons; I made a new one for the flaps since the length and hole spacing are different. Here, I'm using it to drill the flap skins.

ALobjms.png


Since I used the same drill jig for both the skin and the stiffeners, any stiffener fits any skin location.

Now for something that's harder.

Jim Bede died July 9th. For those of you that don't know who he was, take a look at www.bededcorp.com. I never met the man, but when I was a teenager, learning to fly, the BD-1 was announced and caught my attention. It was never produced as originally planned but later became the Yankee and the Grumman Tiger.

When I went to college, Bede was selling kits for the BD-5. At the time, Burt Rutan was his flight test director. Bede also was taking deposits for a certified BD-5, which he hadn't quite got certified yet - and never did. He'd sold over 4,000 kits and taken over 4,000 deposits for the certified version.

There were numerous issues with the planes. Two that I recollect were significant enough. He never found a reliable engine installation and thus never delivered that package - since the engine was buried in the fuselage behind the pilot, that was a significant lack. The other major issue was that the plane was available with short wings and long wings and it turned out that the short wings were really too short.

While I was in aerospace engineering school, I built a large portion of one of the short-wing kits for a local man. It was a great college job. In spite of the fact that all the riveted joints were bonded with Pro-Seal, it was fun.

Jim Bede's inability to produce production aircraft persisted throughout his career, the BD-4 being an important exception. Nonetheless, he was an innovative designer. There are enough kits out there that after-market developers did eventually provide some reasonably acceptable parts to complete the aircraft. Note that these two BD-5s use different engines, or at least different installations.

Kr1l3eW.png


Thanks, Jim. You helped put me through college and gave me some great experiences. The BD-5 kit led directly to the current RV-3B that I'm now building, this time for myself.

Dave
 
Last edited:
Saving Weight

The deal is, every gram counts. Seek it out wherever you can find it.

In this case, it was only 3 grams, achieved by rounding the corners of the flap's stiffeners, but I've been doing this all through the construction so far.

The photo shows the before and the after case.

Y56F7p8.png


I didn't draw or trace the curves. All I did was snip the corners off and rounded the ends with a coarse mill file, following up with a fine mill file.

The flap skins are mostly dimpled now and when that's complete I'll prime them. Ran out of those nails used for dimpling holes where I can't get a regular tool to.

Remember that cracked aileron nose rib? The new one arrived today, thanks Van's for excellent support even in Oshkosh week!

Dave
 
Last edited:
Thank you for posting

Next year I will be building RV-3 and I've always wandered why some RV-3's weight 800+lbs. Van's site says 750 lbs. I guess rounding up all off the corners eventually will add up to some real weight loss, lol. Building RV-3 is hard by itself, building it under 750 lbs takes true dedication, thanks Dave.
Was 3 grams per stiffener or all off them? Do you keep track of weight all of the parts?
 
Last edited:
Rounding ends

I thought that was the way they were supposed to be done. I actually did something right.
Any time a hole is close, I draw a minimum edge line so I can't remove too much.
 
Next year I will be building RV-3 and I've always wandered why some RV-3's weight 800+lbs. Van's site says 750 lbs. I guess rounding up all off the corners eventually will add up to some real weight loss, lol. Building RV-3 is hard by itself, building it under 750 lbs takes true dedication, thanks Dave.
Was 3 grams per stiffener or all off them? Do you keep track of weight all of the parts?

Unfortunately that 3 grams was for the entire set of flap stiffeners. This isn't the quickest way to save weight. I tapered the tie-down fittings (see post #96) and saved more weight than this and it took less time. Still, I regard it as worth doing.

No, I don't track every part. But I go after weight savings where it appears feasible, and where I don't need to do a stress analysis of the part. One of the reasons I'm building a kit airplane is that after retiring from a career as an aerospace stress analyst, I didn't want to have to analyze a whole new-design plane. I have not done some things that I felt were feasible but which Van's said not to do or which I would have needed to stress analyze for.

The gold standard for weight savings is the RV-3B that Andy Hill just completed, at less than 750 pounds with an IO-320 and an electrical system. Most of his purchased parts were chosen for light weight, and he used a narrow-deck engine because it's lighter. He proved it can be done. He left out, as far as I know, some things that I'm including: an autopilot (see post #135) and lights (see post #95 and note that the homebuilt landing light mount I made saved over 100 grams compared to Duckwork's - but still, I added a light and wires and eventually a circuit breaker). He saved more weight by using Beringer's wheels and brakes.

Andy's example demonstrates that the major weight savings isn't in the airframe. It's in the parts that attach to it. They need to be chosen with great care and considerable discipline. In at least one case, he appears to have accepted a maintenance difficulty for the weight savings it brought.

I expect my plane to be heavier than his - but I'll do what I can.

Dave
 
Last edited:
Finished the new left aileron. I tracked the hours spent on this one. It took about 42.6 hours of my time and perhaps another 1.4 of a friend's who helped me buck the spar top flange rivets. I'd previously done that myself, using an L-shaped bucking bar, a shop light dropped inside the aileron and an inspection mirror. But that's how I damaged it, so this time I got help.

Working on the flaps now. The stiffeners are riveted on. I had a moment of considerable dismay when the retaining spring on the rivet gun unscrewed, the back-rivet set dropped on the floor and the spring propelled the plastic pusher to some mysterious place where it has not been found. You can read about it in this thread, which discusses the effect and its ramifications.

I found that a 7/16" box end wrench, pressed down around the rivet, makes a satisfactory substitute if you should find yourself in that position one day. Just put the end of the back-rivet set in the center of the box end and press the box end down on the parts, holding them and the set securely. It takes both hands but works okay.

I spent the evening figuring out where to put the doubler on the spars. If you do a search for flaps you'll eventually come across a recommendation that the inboard rib be moved inboard 7/8", and that the top flange of the spar be 49.5" long. The 49.5" comes from:

48" from the plans + 7/8" extra + 5/8" = 49.5".

The 5/8" is the flange width of the FL-303 rib and please be careful about where you're measuring, because the plans show 48" to the outboard side of the FL-303 rib, and doesn't actually mention the dimension to the inboard side of the rib.

I meant to follow the 7/8" advice and in fact confirmed it with David Howe, but somehow on my flaps I made it an even 1" instead, since that's where I put the inboard set of stiffeners. So on my plane, unless I can shave a bit from the FL-303 flange (unlikely) I'll use the 1" dimension instead.

The bottom flange of the flap spar is limited by the spar's length as received, 51". The plans say that it should be 51 3/8", I think, but the part itself is only 51".

Dave
 
Next year I will be building RV-3 and I've always wandered why some RV-3's weight 800+lbs. Van's site says 750 lbs. I guess rounding up all off the corners eventually will add up to some real weight loss, lol. Building RV-3 is hard by itself, building it under 750 lbs takes true dedication, thanks Dave.
Was 3 grams per stiffener or all off them? Do you keep track of weight all of the parts?
Dave has commented above re our RV-3B: IO-320, VP Prop, Full Inverted, Basic Weight (unpainted) 733lbs.

In the basic parts from Vans there are weight savings to be made, but not dramatic. For instance, each Wing Rib I weighed before and after "hole cutting" and it saved 0.77lb total. I would guess almost every RV-3 has that weight saving applied? Aileron / Flap spars another 0.8lb, Flap / Aileron stiffeners 0.4lb.

The "state of mind" however is important - have spent all that time to save a few oz, you need to look at every nut, bolt, washer and decide if shorter / thinner hardware will suffice in that application?

But, as Dave says, the real "savings" come in not adding junk in the first place, or picking the lightest part you can. An example is a VHF radio. Now I cannot see why Brand X (or rather G :D ) is any better than Brand Z - you press a button and say "Hello Airport". It replies "Hello Plane". End of?

A Garmin SL-30 weighs 3.3lbs. A Dittel KRT2 weighs 0.8lbs. So the Garmin wipes out the entire Wing Lightning hole process in 1 go, for also I think a much higher price?

How far you want to go will depend on the "Mission" - we were fortunate enough to have a higher spec'd RV-8, so the 3 really could be "minimalist", and try some weight saving ideas.

If weight savings is your aim in a new RV-3, you need the version of the plans that shows the area forward of the pilot as "Fuselage Fuel Tank [option]" and leave that out. Not the version showing "Airbus Avionics Bay" :D There is a lot of room there, and very easy to (ab)use it if lightweight is the aim.

PS re
In at least one case, he appears to have accepted a maintenance difficulty for the weight savings it brought.
not sure what this was? Maybe the Oil Filter? Having now done an Oil & Filter change, not a factor. The firewall cutout is "upside down" from most RVs i.e. the sloped part is the lower half. The aft facing Oil Filter (avoids an expensive and heavy B&C adapter) just extends into the cutout. But filter comes on / off no problem.

PPS CG needs to be a consideration, the RV-3 was designed for a 235 / wood FP prop at the front, so a 320 + VP prop is going to be nose heavy. See Randy's site (despite a light VP prop) for the fwd CG, and how he improved Basic CG (and handling) by moving the PC680 to the rear (57.08" to 57.56"). Ours is currently 57.46", and fine, but further aft (like Randy's) would be better, and no restriction on aft [with] or aeros [without] baggage. We could save 1.5lbs on the tailwheel parts, but would adversely affect CG. I think paint (10-15lbs) will bring CG back, so the tailwheel savings might click in then? So as Dave says, weight savings firewall forward are doubly important - not just saved weight, but where that weight is saved e.g. try to avoid a front mounted alternator - vacuum pad is not only lighter, but further aft...

Finally Randy's website is a gold mine of useful info, with little unnecessary waffle. He has a "weight" table that you can expand on, and now following through the LOP EGT balancing with AP - so if you're still reading VAF Randy - many thanks ;)
 
Andy, yeah, I had in mind the oil filter for that "maintenance difficulty" - and am glad to read that the oil change wasn't an issue. Might give that one a try myself, thanks.

Dave
 
WD-306

Van's made my WD-306 Flap Brackets to the plans. I checked. They are fabricated on Drawing 30 and installed on Drawing 9. If you're scratch-building, don't make them to the plans - make them to fit. They fit inside the FL-303 Flap Ribs.

This shows the trim line that I need to cut in the .040 4130 steel.

qFR83r7.png


Drilled and deburred and primed the spars and doublers together but that's about all I did today.

Dave
 
Last edited:
I've been busy lately and haven't worked much on the project. But it's not been a total loss. The flaps are ready for the deburring and dimpling, or will be after I install the hinges. And that's awaiting the aileron hinge installation, and then installing the ailerons, so that I'll know where the flaps fit.

The hinges are coming but I don't have photos yet. So here for your enjoyment, is a look at disassembled flaps and some ailerons at the bottom of the pile.

6jZdODs.png


Dave
 
Last edited:
Aileron Hinges On

I riveted the aileron hinges to the wings. Here's one of them.

Zl7uARL.png


For some reason that I can't figure out, the left wing was considerably more difficult than the right wing to rivet. The pieces fit as well, access was as good, the lighting wasn't any worse and both the inboard and outboard hinges took much longer on the left than the right.

But they're on.

That black tape is there to remind me that the pushrod passes that way.

I've started making the stiffeners for my third left aileron. You might recollect that I just replaced the original due to some dents that it had accumulated. A good look at the replacement shows that it had a similar issue. About when I get the stiffeners finished, the rest of this aileron will be delivered.

Hope this one is better.

Dave
 
Last edited:
Wing Jig

Recently I had a couple requests for details of my wing or empennage jig. Since the wing jig could be made into an empennage jig, here's how it's built.

Make two of these end frames. The wood doesn't have to be straight - but it MUST not be twisted.

Make the corner pieces like I've drawn, not like I've built. I screwed up one set. I used 1/2" thick cabinet plywood, the many-layered stuff.

pSOi141.png


Here's the whole assembly. The corner braces are reasonably large L-shaped pieces from Home Depot, screwed to the frames and the top cross-pieces.

Missing dimension: The frames have a clear space between the uprights. The gap's 101 inches wide.

8IS4n4o.png


This photo shows the end brace that's essential. Don't neglect it. It fastens securely to the wall, preferably to a stud.

COR8uQJ.png


Here's a detail showing the wire bracing. The wires should be tight, but don't pull the eye screws out of the wood or damage anything. Note the turnbuckles and that one of the gussets was cut too short.

lszeTsG.png


This shows an outboard attachment. I bolted some short angles to the outboard rib and clamped them to the support brackets. Worked very well. I used nutplates on the rib but that was foolish; ordinary nuts would have been fine. Avoid the tooling holes or it'll be harder to align the wing.

hivgC8S.png


Finally, here's the inboard main spar attachment. Pretty simple, eh?

Yes, it's clamped, but the clamp is out of sight.

oYYl2DR.png


To make this into an empennage jig, I think I'd try to find a straight 4x8, if there is such a thing, and bolt it to one wing's side of the uprights. Probably waist height or counter height would work. Perhaps make a work table for it out of that white Melamine-coated particle board they use for cabinets; it's a nice material to use for work tables.

After the empennage is complete, remove the 4x8 and you've got a wing jig.

Dave
 
Last edited:
As always nice work David.

The attention to detail starting with the jig device and careful construction of various parts will make for a fine airplane.

I remain impressed with your patience and skill with this project.
 
I've started the new left-hand aileron. It took me four hours to make these stiffeners. Of course one hour of that was making some angles after I realized that I'd run out and hadn't ordered new blank angles to cut up.

Had some .025 aluminum, so I cut out the blanks, deburred and bent them, and then finished them. Only had to do seven that way since I had enough prebent angle to make the first seven.

2clWzRW.png


That was done yesterday. Today the new parts arrived and I've started working on them. The spar is marked and the end reinforcements made. The skin is marked so that I can drill for the stiffeners and the upper spar cap.

Dave
 
Last edited:
Working on that replacement aileron....

Here are the stiffeners riveted to the skin. For builders of the other RVs, the RV-3B has a one-piece aileron skin. This makes it a bit more difficult to build. The skin arrived with the trailing edge bent more than I'd prefer so I used a galvanized pipe that I had handy, about 1 1/2 inches diameter and about 6 feet long, to press into the bend while the skin was trailing edge down on the work table. This opened it up just enough to back-rivet the stiffeners.

If your eyes are sharp, you might see that the aft-most rivets are blind. I didn't want to try to unbend the skin far enough to install solid rivets there. I figured that blind ones were better for that.

ab2s8Un.png


The spar gets drilled to the top of the skin early. You can just see those holes in the photo below. I was reluctant to drill the 1 3/4" lightening holes because when I do, the spar warps. It bends away from the flanges. When it's clecoed (and later riveted) to the skin, that goes away, but it's a tiny bit awkward in the meantime.

Still, the sequence would have been affected if I'd waited; the bottom flange doesn't get drilled to the skin until quite late in the process. So I made these holes. Then I riveted the end reinforcement flanges on.

The plans call for AN470AD4-5 rivets but the -4 are more suitable here. For the two flush rivets, those are also -4. And you know what? For all four ailerons I've worked on so far, I missed that their diameter is a 3. Yes, I installed an 1/8" rivet where only a 3/32" was required. But I did manage to have enough edge distance. Those will have to come out for the outboard main ribs and then I can put them back in; they're in now so that the reinforcement lays flush on the spar. Without them it lifts a bit and then when I drill the holes for the nose rib (the next step), it's hard to deburr them.

bwH5gTN.png


My drill board is a 2' x 4' piece of that white Melamine-coated particle board I like. It's flat and has a nice finish. It's sold in the big box stores. It doesn't get embedded particles of aluminum and doesn't scratch aluminum. Nice stuff. And this one is getting lighter by the day, with all those holes.

Dave
 
Last edited:
The nose ribs that arrived with this aileron had cracks in the front flange. Here's an example:

HaIYjZX.png


Van's replaced them quite courteously and promptly. Ironically, the new ribs had their front flanges slightly too low. The pipe was lower than the bottom flange. Unfortunately I don't have a photo of that - the gap was about .06 inches.

Since the ribs were already riveted to the spar, I removed the front flanges and made new ones. Ironic, huh? With the front flanges off the ribs, the position of the pipe needed to be controlled fore and aft. I made a tapered plate of .025 as a guide, and by working on only one rib at a time, I was able to use the other one as a control. That let me mark the guide.

cARrBad.png


The top edge of the guide, where the tooling hole is, fit flush to the reinforcement on the spar face. I slid it in until it contacted the pipe and marked that, and that located the distance. I used a Harbor Freight die grinder's wrench to hold the pipe to the bottom flange of the rib.

Here it is jigged up:

Ar8JYBU.png


Finally, here it is with the skin sort of loosely fitted around it Note that I used solid rivets instead of the LP-4-3 blind rivets that aren't specified in the plans - but are in the RV-4 and RV-8 plans.

S5PE0ZS.png


The skin is now taped into position and the trailing edge is bent again after unbending it somewhat to rivet the stiffeners in place. It's pretty clear that I'll need some shims as before.

Dave
 
Last edited:
Oil Coolers

I had previously bought one of Van's EA OIL COOLER II oil coolers and a shutter for this project. Andy Hill found that on his engine, a smaller one would work okay. He had an Earl's 20700, with an engine that because of some internal differences would put more heat into the oil than mine.

I thought that out here sometimes I'd need more cooling than that. Colorado temperatures are more severe than England's, and I fly over the western deserts from time to time. I bought an Earl's 21000ERL from Summit Racing. It has roughly 38% the cooling capacity of the one from Van's.

EK4vhEb.png


Hard to imagine that quite possibly the smaller 20700 one would work fine. It's height is an inch less and the other dimensions stay the same. You can research them here.

This oil cooler is clearly not as well made as the one from Van's. It's almost a pound lighter, though, not counting the shutter and its control. Besides the weight, a side benefit of not using the shutter, assuming I don't need it, will be that I don't need to find a location for its control in the small RV-3B cockpit. I've got the shutter and verified that it can be used with this oil cooler. I'll hang on to the shutter just in case.

One of these days I'll put the oil cooler from Van's in the Classifieds. New, unopened.

Dave
 
Last edited:
The third left aileron continues. When those lightening holes are drilled, the spar warps just a bit. The clecos in the previously-drilled holes through the spar flange and the skin hold that flange nicely in position, and I clamped a straight piece of steel angle to the spar web to hold the bottom flange relatively straight. Then I drilled the holes though the bottom skin and the spar flange.

GSe31Om.png


The leading edge needed a bit more bending around the pipe. To do that, I wanted something a bit smaller diameter than the pipe, so I used the stock for the aileron pushrods. I taped it to the skin and massaged the bend and this worked nicely. Ideally, I should have done this before drilling the bottom flange holes but it turned out okay. It did leave a small gap which the rivets pulled down nicely.

vuOtTp1.png


Shortly it was time to rivet the top flange of the spar to the skin. I'd previously done this by riveting with the gun's set supported by a wooden batten and using an "L"shaped bucking bar to get in to the shop side of the rivets as shown in post #157. The constraints can be seen here.

https://i.imgur.com/SHb7FeP.pngIMG]

Look for the skin overlap on the right; that what I needed to work though, with that overlap opened up and riveting the flange on the left. I was able to do one aileron successfully that way all by myself. I ruined one more by myself and one additional one with the help of a friend - that .016 skin is very fragile.

This time I decided to see if perhaps I could back-rivet it. As you might predict, the straight back riveting set wouldn't get to the flange. I didn't find an offset back riveting tool so I started looking for something, anything, that might do the job. What I found was a "C" tool. This nifty device is driven directly by the rivet gun as shown, and has a 3/16" hole in the other end for any rivet or dimpling set you might wish.

[IMG]https://i.imgur.com/sb5A1Pu.png

Look for the skin overlap on the right; that what I needed to work though, with that overlap opened up and riveting the flange on the left. I was able to do one aileron successfully that way all by myself. I ruined one more by myself and one additional one with the help of a friend - that .016 skin is very fragile.

This time I decided to see if perhaps I could back-rivet it. As you might predict, the straight back riveting set wouldn't get to the flange. I didn't find an offset back riveting tool so I started looking for something, anything, that might do the job. What I found was a "C" tool. This nifty device is driven directly by the rivet gun as shown, and has a 3/16" hole in the other end for any rivet or dimpling set you might wish.

sb5A1Pu.png


I bought this one from The Yard Store.

For what it's worth, the rivet set at the left end is 1/2" long and 1/2" diameter. The box-end wrench is a cheap HF one, 1/2" size.

It still took some care, since the access was awkward and it took two hands: one on the gun and the other pressing the spar flange to the skin with the box-end wrench. The box-end wrench substituted for the plastic spring-loaded tube usually found on back-rivet sets.

I quickly found that the 2x gun, pictured, which I usually use for the 3/32" rivets, was not powerful enough to drive these rivets. I had to use a 3x gun and crank the air pressure up to about 43 or 44 psi. Then it worked okay. That gave me a nice smoothly-driven row of rivets.

Success.

Worth mentioning but not pictured, sorry, is that on this aileron I used shims between the spar web and the nose rivet back flange. Both sides use .120" thick shims, and the need for shims on the upper or lower flanges was much reduced.

Dave
 
Last edited:
I'd saved the wing crate with the idea that it would be useful for a wing cradle. After struggling with various concepts for hanging the wing frames on the wing jig with the leading edge down so that I could hang the ailerons and flaps, I finally realized that it would be much easier to build the cradle now.

UGYfWSh.png


Since I felt that it would be best to lower the leading edge below the side of the crate, I cut some wing-clearance openings in the cradle. Then the center portion of the carpet support was a bit wobbly so I added a strut to other end, which was braced better.

axGGzkd.png


A friend helped me move the wings to the cradle. They don't weigh all that much and it wasn't too hard. Good thing there's no fuel in the tanks. We walked the wings out to the driveway, one at a time, rotated them so that the south end became the new north end, and then rolled the loaded cradle back into the shop, where it nests nicely in between the legs of the jig. Rob Leary helped me move these.

zvCGKCi.png


After adding a few battens to the wing frame to support the right aileron and putting the aileron side of the hinges on the wing's hinges, I measured the distance from the rear spar to the trailing edge of the aileron. You can imagine my astonishment when it was 13.00 inches, exactly what the plans specify. This was so unexpected that I immediately double-checked my measurement and confirmed it. Got lucky there.

Next was adjusting the spanwise position, set with a measurement at the tip. Then I installed the bottom half of the airfoil cut-out to set the up/down position. This was the piece that helped me position the hinge on the rear spar.

21KybeA.png


Here's where that cut-out came from. I used this to locate the aileron hinge holes on the wing. Note the hinge locator fitting.

mHSccXf.png


This is a closer look at the hinge locator fitting. The markings for the rear spar were taken directly from the rear spar, so that provided me with a fore-aft relationship, and the horizontal line that runs through the fitting is 3.0 inches below the chord line and parallel to it; this gave me a vertical reference. I had to draw that before cutting the middle out of the jig, of course, because the chord line that I'd drawn on the plywood got cut out.

TsiztmE.png


Haven't tried on the left aileron yet.

Dave
 
Last edited:
Hey, sorry about the oversized photos on the previous post. I'm replacing the dead links with screenshots from my back up and forgot to shrink them down to 800 pixels wide.

I don't think I posted this photo before. The photo was taken a year ago to show any prospective inspectors or buyers that yes, indeed, I installed anti-rotation parts on the fuel lines.

It shows the anti-rotation devices that I installed on the fuel lines. Note that no safety wire is needed, and I didn't bother to drill any holes for it. Yes, if I ever need to remove the fuel pickup line I'll have to unrivet the brackets (nutplates could have been used), but I decided that was unlikely.

fKNqrbB.png


Putting the bracket on the nut blocked two rotational degrees of freedom at once: the nut can't unscrew, and the fuel pickup line can't rotate in its hole in the access port.

The one on the left is a bit bulkier than I like but that's what it took. Keen weight-conscious readers might observe that I could have lightened these parts, and I agree. I should have.

Dave
 
Last edited:
anti-rotation HOW?

enlarged picture in PS and searched google for "anti-rotation device" to figure out how these prevent rotation > no figure out or findy.

explain the works of an anti-rotation device as your 90 degree bent plates must do.
 
Here's what I mean by two degrees of freedom:

aCVkWJ1.png


This simple line drawing shows the access plate and the elbow that's Pro-Sealed to it. Then the red arrow shows the first axis of rotation; the elbow can rotate in its hole. This is one degree of freedom.

The second axis of rotation, the second degree of freedom, is the nut that's threaded on the end of the elbow to secure the pickup tube. I didn't draw the nut.

You can see that a single wrench placed on the blue circle in the right position can twist both the nut in the blue direction and the elbow in the red direction. That's all the anti-rotation fittings, are, just simple 12-sided box wrenches riveted to the plates to prevent these from moving, as Ken said.

This complies with the intent of Van's service bulletin sb06-2-23.pdf. I used a part that Van's sells, but I forgot the part number. It has four of the fittings in one piece and we have to cut the separate pieces apart. The 12-sided cut-out is pre-stamped, ready to slip over the nut.

Hope this isn't too confusing....

Dave
 
Last edited:
The ailerons are hung, if you can call a couple clecos at each hinge "hung." I haven't drilled the holes out for bolts yet. They check out with a straight edge lining up the tooling holes as well as fitting my shape jig.

jr8b5s.jpg


They have ample free movement. Another thing I haven't added yet are the aileron gap fairings. While that's the logical next step, I thought that I'd have a look at the flap mounting process before that. I don't imagine that there's interference between them but it's worth a check, so that's next.

Since I was out at the hangar the other day, I picked up the right wing tip and brought it home. It's white fiberglass. I made a trial fit on the right wing just to have an idea how it fits and what I'll be in for. Since the empennage tips fit so poorly I wasn't expecting much. In fact, that's why I only brought one of them, figuring that would be bad enough, plus I really didn't expect the left wing to be ready for a fit so soon..

You can imagine my surprise when the tip fit very well indeed. Of course it'll need a bit of trimming to clear the aileron hinge and that sort of thing, to be expected, but aside from that it fits great.

263k66x.jpg


This is another thing that I'll postpone. There will be considerably more fiberglass work later and I'll do it all them, just to have fresh resins.

2mrislt.jpg


Dave
 
I'd previously gotten the flaps to the point that except for the hinges, they were ready to be deburred, dimpled and riveted together. With the ailerons on, it was time to locate the hinge, the hinge brace and do some more drilling.

The flap brace notch for the rear spar inboard fitting isn't shown all that well on SK 28. When I placed the brace on the spar there were some questions. Andy Hill suggested having a look at the RV-4 and RV-8 plans and those showed a substantial notch in the brace.

2ajopwm.jpg


I drilled the lightening holes and figured out a suitable spot for the cut-out and here's what it looks like at the inboard end.

2cxclck.jpg


With that figured out, I set the flap in position on the wing frame and shimmed it to the bottom skin's aft edge until the trailing edge matched the aileron's. Then I measured the shims. This let me position the flap side of the hinge on the flap and drill them together in my vee jig to keep the flap from twisting. I used both sections of hinge there to ensure straightness.

Locating and drilling the hinge fore-aft on the bottom skin was more tricky. Shimming the flap into position wasn't hard but if I tried to drill the skin, brace and hinge together, the hinge would simply fold out of the way. There was no access except at the inboard end. And due to possible straightening of the parts as I brought them together, and wanting to maintain the 1/4" gap to the aileron, I wanted to drill from outboard to inboard.

First, I clamped it all together with the hinge held in the correct place, and located the rivet line. Then I removed the flap brace and hinge and drilled through the skin. Clamping the brace and hinge back together with the skin, I drilled the holes using the skin as a guide. The photo shows the inboard and outboard holes drilled and the piece of angle I used per David Howe's suggestion, to ensure straightness.

i21zbn.jpg


The remaining holes were indeed drilled outboard to inboard, clecoing as I went, so that there was enough stiffness from the cleco in the previous hole to allow me to drill the next hole. As I got close to that one inboard-most hole, I removed its cleco so it could float. But I'd done it right and it didn't shift.

Here's the right hand flap clecoed in position with the aileron on the wing. It's ready to prep and rivet.

2zybj4j.jpg


That's the right-hand flap. Now working on the left-hand flap.

Dave
 
Here's a photo showing the left flap being drilled for the hinge.

iollkz.jpg


Since these holes also connect the skin to the spar flange, I drilled it in the Vee jig.

A bit more work and the left flap, like the right, is now drilled to the wing. At this point, though, both flaps need to be deburred, dimpled, countersunk, etc., and then riveted up. There's some work left.

2rf8qon.jpg


With the flaps off and the flap braces drilled to the skin but not the spar, I removed both ailerons and started work on the aileron gap fairing. The plans call for an RV-3B part, W-323, and Randy Levold recommended the W-824 gap fairing instead. Van's sold me the W-724 which you see below.

6sdsba.jpg


While this appears to simplify things, and it does, there are a few bits to consider. First, it's about 6" too long so you'll have to trim one end. Actually you'll have to trim both ends somewhat. Once that's done, it will fit reasonably well, except that a few of the pre-punched rivet holes are in exactly the wrong places. And a few more are almost in the wrong places. Still, it does simplify things and I don't suppose it weighs any more. It might weigh less.

Since its shape is different than the W-323 fairing that's designed for the plane, when I got the fairing clamped in place, I hung the aileron back on and checked. There's ample clearance.

Here's the W-323 part for reference. Notice the nice curve and the flange that's hidden by that curve.

258wlfm.jpg


One thing about the W-323 part, is that you'll probably need to trim the ends to fit around the hinges. I'm not sure about that since I haven't seen one, but I suspect that would be necessary.

I realized that I had enough of the electrical parts, things like the alternator, regulator and solenoids, plus a few other parts and have identified some of the others, so that I could start on the electrical diagram. I'm doing it by systems, and now have a draft schematic of the power/starter system and another of the audio system.

I'm following the schematics in "The Aeroelectric Connection" and on the www.bandc.biz site for the sort of operation I have in mind. These are being tweaked to fit the particular components that I'm accumulating or have chosen. I'm drawing this on a Mac graphics program called "Graphics." It used to be called iDraw but they changed its name. This is a general-purpose drawing (not CAD) program, not a schematic program, and for me that's okay. I can draw something once and copy it all I want and I already know how to use the program.

Right now these schematics are relatively immature. After they grow up some and when I work more on the systems than the airframe, I'll present them.

Dave
 
Back
Top