Frank Justice has some notes on fuselage construction on the Net. Get them -- they're a >must-have item. I like FJ's order of construction... the skeleton supports itself without needing to much extra bracing. Mostly, I have followed FJ's order. These notes follow the order of FJ's notes.
Unfortunately George's video is in a different order, necessitating a lot of fast-forwarding and rewinding. Also unfortunately, George goofed a little -- he put in his fresh air inlets before he did the rudder pedals. They were too close and wouldn't allow for removal of the rudder pedal mounting bolts. Whoops! He had to make a special mount for his rudder pedals so the bolts could come out. Do your rudder pedals first, then the inlets. Watch the tape and you'll see it.
Fuselage Kit Crate Size:
Inventorying was simple, the only parts I had trouble identifying were the steel bits. Be careful... one of the fuselage bulkheads is very light. The edges of the firewall are sharp enough to cut through your skin too. My plans don't show what parts the full-swivel tailwheel is made up of. It turned out that the tailwheel fork was missing from the kit. The tailwheel spring, which I'd expected to be a leaf spring or similar is a tapered steel rod. Mine was loosely bolted to the collar that the tailwheel fork will go in.
First job was to prime the steel parts... there's quite a lot of cleaning up and polishing involved. Note that one of the small baggies contains some steel angle parts that will also need to be primed. Note also that there's 4 steel parts clecoed to the firewall assembly.
However, all the firewall parts come pre-cut and pre-assembled (apart from the two pairs of .063 'ties' for connecting the diagonal reinforcements together), so a fair amount of the first of GeorgeO's video is now irrelevant. All you need to do is to start drilling, using the pre-punched holes in the firewall as a template. There's a couple of 3/16" holes in the firewall and other parts... I didn't drill those through (I figure they're tooling holes or something). A couple of the #30 holes just hit the edge of an underlying part.
The ends of the bottom stiffener angle do need to be rounded so that they more or less follow the shape of the firewall. Otherwise, the F672 bottom skin won't fit over them.
Note that the dimensions given in the plans for the 'tie' pieces are wrong. The flat pieces need to be about 2 1/2" long (rather than the 2" given) to reach the second rivet. It's a little easier to rivet the angled ties to their angles before the angles are riveted to the firewall.
Some of the holes in the aluminium angle reinforcements are too close
to the flange part for back-riveting. These I did as best I could, then
finished them off with my 1/8" universal double-offset rivet set.
Back-rivetting the firewall is difficult: RV-List message posted by: Larry Olson <lolson@doitnow.com>: I used the clamp the back rivet plate to the firewall method supplied by Lloyd Bentley... IT WORKED
If (like me) you're building a taildragger, trim back about an inch or two ofthe ends of the firewall bottom flange to about 3/16" wide. This is to allow clearance for the gear legs.
Construction of the false spar is also described there.
To attach the control column mounts, I drew lines across the bottom of the mount 1/2" from the end, and lengthwise 7/16" in from the flange edge. Through the holes in the F604, I could see where these lines cross. Checking with the Wd610, they were exactly the right distance apart.
I suggest positioning the c/c mounts as low as possible on the spar (i.e. with the bottom of the mount against the bottom flange of the F604). I fitted mine as per the plans, and later had to trim the top of the rib holes to allow full movement. I also couldn't fit the Manual Aileron Trim as far forward as Vans suggested. Lowering the c/c mounts would have fixed (or at least minimised) these problems without any adverse side-effects.
Also, rivet (any small size) or screw the c/c mounts to the bulkhead; NB: flush on the front side of the bulkhead. This isn't structural (the 3/16" bolts through top and bottom of the mount are)... it just holds the mounts in place when the wings are moved.
If you can figure out the right place, it would be a good idea to cut the 4" wide c/c clearance slots in the top flange of the F604 now rather than later. Even if you can't, cut a slot wide enough for the stick to fit into just outboard of the c/c mount. This will allow you to check interference of the c/c with the F618/F619 ribs before they're rivetted in place.
RV-List message posted by: Bob Skinner <bskinr@trib.com>: .045" gap (i.e. making the dummy spar .045" thicker than the real spar) might be a bit much but I do think there is an advantage to not getting things too tight.
You can always add a shim, if necessary. If the gap is too close, installation of the wings can be difficult. We had a tight fit on the 6A that I'm helping with. My six had a little looser fit. If I were to do it again, I'd shoot for a .020" gap, or so. Most of the forward part of 604 will bolt down solid as it flexes readily. The outboard area will not flex so you don't want much of a gap in this area.
RV-List message posted by: donspawn@juno.com: I planed a 2x8 to +.030 over my .125 spar. You want your wings to fit later. I think I could have been .010 over & it would have been OK. I cut them 7 inches long like Frank J suggested. I would only go out to the triangle piece so you can drive the rivets in the next to outboard seat rib.
Later to align & fit the .062 stiffeners on the F672 forward bottom skin, you will have to build "thru" spars to fit the F699 angle brackets to the spar holes. (like George did).
For an alternative to building a wood "spar", see Sam Buchanan's method.
RV-List message posted by Bob Skinner: You can modify the small piece of "U" channel at the top of 604 to increase space for wires, antennas and static line. I slit a piece of thin walled vynal tubing to wrap around wires at that location and tie wrapped it to the wires. On the other side, I used spiral wrap.
When marking and drilling the F605B bar, FJ says to mark the rib webs on the bar using plan 33 (section E-E') -- that's necessary because the seat rib locations (the first rivet inboard of the F605C) aren't shown on plan 26. To avoid cumulative errors, calculate the positions of the outer ribs rather than just adding 4 3/4" (or whatever) to the position of the previous rib.
Not very clear from the plan or FJ's notes is that the outboard rib (F615) on each side is bolted to the F605 structure. Because of the bend in the F605C, the first rivet inboard of this rib is about 1/4" inboard of the bend line of the F605C. I had no real interference problems with the seatbelt anchor bolts. Until I assembled the bulkhead. Then I found that the outboard seatbelt anchor holes lined up almost exactly with the flanges of the F605Ds. Arrgghhh! To fix this, I cut through the flange about an inch from the end and flattened it to match the web, then match-drilled the bolt hole through the F605D as well. I'll rivet a new flange to the F605D, clear of the bolt hole.
When FJ says to 'cut off 1/2" of the outside edge flange, just over 1/8" deep', what he means is cut off 1/2" of the flange, and 1/8" of the web. You may also need to do the same to the F605E... I didn't, but haven't assembled the bulkhead to longeron yet, so can't be sure.
Note that the F605H and I pieces need to go between the outboard flanges of the F605D and E pieces. Put them in place before drilling the D and E pieces together.
To make the F605I, I cut 2 x 9" pieces from the .032x1/2"x9' (actually 3x3') stock. Dunno if that was the right thing to do or not, but there didn't seem to be any other .032x1/2" strip. There was a piece of .062x1/2"x18" to cut the F605H from.
FJ says to cut down the F605E to no more than 9" long. Van says 9 3/4" in the plans (revised from 10 1/2"). I went with Vans. Note that the F605E as received is 10 1/2" long. Later, I found that the top rivet holding the F605E to the rest of the F605 bulkhead interferes with the aft end of the armrest. To avoid this, use a flush rivet in this location.
Warning for those building with electric flaps -- don't cut the large
holes in the F605D parts.
If you are building manual flaps and intending to shorten the flap handle (as in "18 years of RV-Ator" pg 91, from RV-Ator 6/90), you'll need to place the holes in the F605 about 1/4" or so higher.
The tip-up canopy has a latch mechanism operated from the left-hand side. In particular, there's a UHMW plastic bearing block to be bolted to each side of the the F605, and a couple of steel brackets to be rivetted to the left-hand side. These go in amongst the rivets holding the F605 together.
The static line (and taillight (and maybe other) wiring) needs to go through the F605 bulkhead. In particular, the static line needs to go through on the LH side, at the same level as the main longeron.
RV-List message posted by: Richard Reynolds <RVReynolds@macs.net>: To determine the rivet spacing for the F605E, either scale from the right side view or count the nunber and lay them out.
NOTE! If you are building a tip-up, lay out the parts for the canopy lock, part WD-617, bearing block C-611, and bracket C623 and don't put rivets in way of these parts. Note that C623 is only on the left side of the plane (dwgs 51-53) (right side of dwg since you are looking aft, confused yet?)
ALSO!!@#! Trim off about 3/4 inches of the lower pointed end of F-605E so that the rivets in this area do not interfer with the rivets for the angle on the lower side of the aft end of the arm rest F-620 (dwg 32).
Also be careful with the rivet lay out in the F605G angle, be sure you can get to them to drive them and the have edge distances with F605F. It's tight up in that corner.
The rectangular hole in the bottom of the F605 bulkhead is for the elevator pushrod to go through. That pushrod will be inserted from behind the F606 bulkhead. To make this insertion easier, make the bottom of the hole about 1/8"-1/4" lower. The bottom (and top) of the hole could be rounded if you wish.
Don't dimple the holes to join the F606A pieces at the top until you've also drill them to the F687.
I postponed drilling the .032x3/4"x1" F606C angle to the F606 bulkhead until later, mainly because it looked tricky to figure out exactly where to rivet it to. In hindsight, I think it would have been a good idea to figure this out, then drill and rivet the F606C to the F606 bulkhead at this stage. Locating the F606C isn't very tricky -- it just lines up with the tops of all the baggage ribs.
I think it's also a good idea to drill #30 and cleco the F651 and F652 baggage compartment wall parts to the F606 at this stage. By doing this, you'll be stiffening the bulkhead a lot. Alternatively, it would be a good idea to build a plywood brace for the F606 bulkhead. You'll need a large piece of plywood (you need a large workbench to build the bulkhead on too).
RV-List message posted by: donspawn@juno.com (Don Jordan): Which way is up for the upper half of the baggage cover. One side has a roll or bend ( like we do the skins for overlap). The dwg does not show it up or down. I think it goes up & the other (flat side) over laps the F651, The 1/2 inch overlap of the 652 on the 651 is also not shown. I assumed that from the full size view of the harness guides.
AS IT TURNS OUT, THE ROLL OR BEND GOES DOWN.... TOM @ Vans
Note that the hole positions shown in the plans for attaching the F651 main baggage wall to the F606 don't work out... according to the dimensions given, some of the holes are at the top of the folds in the wall. I drilled mine 4 1/2" from the bottom then at 4 1/2" and 6 1/2" spacings. The top row needs to be about 1/4" from the top... this will also be 1/4" from the bottom of the F652 upper part.
Be careful of the dimpling direction... holes above the tops of the ribs are dimpled flush side forward -- the F606C, F651, and F652 pieces will back against the front of the F606 bulkhead. Holes through the F606B are dimpled flush side aft. I don't know why this is, but it is mentioned in the plans. Note that the F606C overlaps the top holes which attach the F606A and B together. Either use flush rivets here (flush side forward), or leave these clecoed until you attach the F606C.
The rectangular hole in the bottom of the F606 bulkhead is for the elevator pushrod to go through. That pushrod will be inserted from behind the F606 bulkhead. To make this insertion easier, make the top of the hole about 1/8"-1/4" higher. The top (and bottom) of the hole could be rounded if you wish.
Mike Thompson wrote: I recommend using -3 rivets at the top of the F606 bulkhead with the expectation of drilling them out later to attach the F687 rib. That way you will be drilling out -3 rivets and then enlarging the hole to #30 when you back-drill to the 687 rib. [This might only apply to sliding canopies??]
Back in 1996, there was some discussion about this on the RV-list:
gil@rassp.hac.com (Gil Alexander) wrote to the RV-list:
1. Cut off the rear flange of both F-627L and F-627R. Rivet
on a new flange (3/4 by 3/4 by 0.032 is OK) so that the flanges now face
outwards. Use the same number of rivets shown that hold the flange to the
F-606 bulkhead. This also helps the consistent problem of these two
parts being too long as provided in the kit.
2. Cut off the flange from the front end of the F-629 horizontal stiffener, and also add a new flange (as in 1) facing outwards. This also makes this part easier to fit lengthwise.
3. Make a new F630 plate 5.5 inches wide in the area were it mates directly against the F-606 bulkhead. Note that the portion protruding above the F-606 is offset to the left to pick up the already outward facing flange of F-628 vertical stiffener. This will make it wide enough to pick up the now outward facing flanges of F-627L&R, tying the structure together as designed.
Vans said: The flange of the rib that overhangs the hole that the pushrod goes through is to be CUT AWAY to enlarge it to the original hole dimension.... the F-630 doubler plate is in there to beef up this area and so the flange of the baggage rib is of no consequence... tom
The placement of these ribs took me some time to figure out from the plans... F628 is vertical, down the F606 bulkhead 1" right of the centreline. It has .062x3/4"x3/4" angle riveted to its aft edge. F629 is horizontal, fore-and-aft, 1" left of the centreline. (Or maybe they're 2" either side of the centreline?) It also has a .062x3/4"x3/4" angle riveted to its top edge. These two angles are the mounts for the elevator bellcrank.
Bag 654P is the plastic ziplock bag, not one of the brown paper bags.
Drawing 30 wasn't included in my plans set, but the layout of these ribs is clear enough from the half-size drawing in the back of Vans manual.
Fabrication of these parts is described under the "Removing The Fuselage from the Jig" section of Vans manual (page 8-11).
F628 is attached to the F606 by 4 rivets at the bottom (plan 33, section A-A') and top. The top of the F628 should not be square -- it needs to slope down a little (about 1/8") to match the slope of the turtledeck.
The flange of my F629 overlapped the elevator pushrod hole by about 3/16". That left a marginal distance between the web and edge for riveting. I went a bit closer to the web so that at least the F630 would have good edge distance.
Note that the F630 doesn't attach symmetrically on the centreline -- it is offset by 5/16" or so, so that both the F628 and F629 flanges attach to it. One edge of it is alongside the 5/8" trim cable hole. Consequently, the elevator pushrod hole in the F630 is not in the middle of the F630 -- it is 5/8" from one edge.
The holes to countersink in the short angle are those that attach it to the F630.
RV-List message posted by: Alex Peterson <alexpeterson@cwix.com>: The holes through the bulkheads for the forward elevator pushrod in the 6/6A need to be off centre to accommodate mounting the elevator bellcrank off centre (spacers are not equal length, see dwg 40, middle of sheet). Maybe newer drawings show this, but if your drawings show these holes through bulkheads 605 and 606 to be on centre, they are wrong.
I'm fairly sure that Alex has got the wrong answer though -- the drawings of the bulkheads are quite clear that the elevator pushrod hole is on the centreline. Bruce Black, another local RV-6 builder, reckons that the front flange on the F629 faces the wrong way. He cut his off, and riveted a new flange on the other side.
The upper flange of the F651 is the one which faces in the opposite direction to the folds (that's why it needs to be cut away). I cut 2" off each end.
I also needed to deepen the longeron notch, and also the indentation alongside it.
Plan 47 shows a .063" reinforcing angle attaching the F687 to the F607.
RV-List message posted by: Alex Peterson <alexpeterson@cwix.com>: Cut a small notch in the interior edge of the bottom web of F607 for removal of the forward elevator pushrod.
The bottom bolt hole location shown in Dwg 34 Section C-C' is very close to the bottom tooling hole. I used the tooling hole as the bolt hole.
However! Reading ahead in Vans manual, you shouldn't drill the Wd609 to the F612 just yet.
Note that the female template made from the plans will be more useful than the male one.
A local RV builder, Bruce Black, told me he bent the longerons on the
jig... clamp down the straight section, then use a tool like Mlfred@aol.com
describes below to gradually bend the longerons to the required curve.
His method seems to have worked just fine.
Someone wrote to the RV-list: With the help of my trusty helper (my wife) we bent the top longerons as described in the manual and in Frank J's supplement. After laying them on the jig and positioning them for width at each station they fit great except at the firewall weldments. At the firewall the weldments are cocked so that the longerons will be twisted from the vertical plane. My longerons are vertical at this stage. Did I do something wrong or should I just twist them and make them fit.? I just sort of figured that once the longerons were bent they would fall into place.
Dennis Persyk replied: The longerons require a slight twist from the F602 the to firewall weldment. It is just a matter of a few degrees. Some builders just make the longerons fit without pre-twist, thereby riveting the longerons with a slight built-in torsional twist. More important however is to make sure the weldments point to the inflection (bend) point on the jig. The only way to check this is to clamp a piece of straight angle to the weldment and see if it intersects the jig where the longeron begins its bend. In my case I had to hold the split weldment bent off to one side with a tiny C-clamp while I whittled down the other leaf with an angle die grinder and 2 inch sanding disc. Failure to check this will result in a bend in the straight part of the longeron to match it up to the weldment. The longeron itself is not suitable for this test as it may by now be non-straight, so use another piece of angle.
RV-List message posted by Mlfred@aol.com: Twisting tool: 3' section of 2X4. Cut a saw kerf (groove left by the blade) 3/4" deep, 1/8" wide, 4" from one end. The angle will fit into this tool (tightly). It takes a surprising amount of twist with this tool (110 deg. or so) to get the required small twist. Remember- the longeron will only twist between the clamp and the side of the tool nearest the clamp.
RV-List message posted by smcdaniels@juno.com (SCOTT R MCDANIELS): Use 2 adjustable (crescent) wrenches with tape on the jaws. Clamp the wrenches on the longeron at the 2 opposite ends of where you want the twist to occur and twist until you have what you want. This method allows you to do the twisting in the jig until you get the longerons to match the weldments.
The jig is a hefty item -- 14' long by 4' wide. It needs two big people to lift it. If necessary, the firewall end could be placed against a wall, but I think that would be inconvenient. So you need a space about 20' long by 8' wide (plus workbench, storage, etc.) to build your fuselage.
FJ says to make the jig higher than the plans say by about 6". My borrowed
jig is 2" shorter. Dunno how much difference that'll make.
My tailpost support is a 4x2... I had to cut some notches in it for the longerons.
I didn't drill the bottom engine mount holes in the firewall yet. I figured that I'd rather do that when I actually have the engine mount. The top holes are pre-drilled, so I went ahead and drilled those 1/4" to attach the firewall to the jig. The bottom (top) of the firewall is just clamped to the jig.