. . . . . (compiled from many amateur sources by David Carter)

. . . . . . . . . . . . . . . . . . . Last changed 5 Sep 1998/21:00 CDT & sent to "Bunny's Guide for RV Building" for posting soon thereafter. Visitors= 

TO E-MAIL THE EDITOR OF THIS DOCUMENT: dcarter@datarecall.net

DISCLAIMER: This document is a heavily expanded version of Van's RV-6 Builder's Manual, 10/24/96 6SCT6PP.doc, "SUBASSEMBLY 3 THE RUDDER", starting on page 6-8, with text from the official manual shown in quotes. Everything else is preceded by "(added:)" followed by the ideas, tips, other steps, and observations added by David Carter from his own experience, from the RV-list, from Frank van der Hulst's "The Bunny's Guide to RV Building", and Sam Buchanan's web site. Some of Van's text was deleted or moved and will be shown as "(delete . . .)" or "(moved . . . to . . .)"

This document has no connection to Van's Aircraft Inc. Van's has no responsibility for the way their official manual has been altered. The editor of this collection of "many builder's observations and approaches to building an RV-6" disclaims any responsibility for anyone's use of this manual. The editor is simply another "first time builder", has never built any other aircraft, is not an aircraft mechanic, and knows nothing about building aircraft other than what he has learned informally from other amateur home builders and from his own experience. IF YOU WANT OFFICIAL GUIDANCE FOR YOUR PROJECT, CONTACT VAN'S AIRCRAFT DIRECTLY.

This document was created in WordPerfect 6.0 for DOS and converted to HTML simply by adding the [HTML][HEAD][TITLE] . . .[/TITLE] LINE and the [/HEAD][BODY] LINE at top, then [P] codes at the end of every paragraph, which automatically ends the paragraph and inserts a blank line after it, then a single line at end: [/BODY][/HTML] , then "saving as" file type "ASCII, standard". The [ and ] symbols are actually < and > but they don't display in an HTML document. The [P] codes can go at the end of a paragraph or at the beginning of the following paragraph. It was easier for me to simply run the cursor down the left margin of the screen and repetitively paste [P] at the start of every paragraph.

Now that you have it easily accessable on your hard drive, you can edit it with your word processor to add margins and page numbering codes of your own choosing and to add your own "words of wisdom" and delete any of mine, then print a neat copy to work from or show to someone else. COMMENT: It having been saved as an ASCII file, it has lots of hard returns that may look funny on your word processor. Web browsers ignore those hard returns. If you are serious about editing and re-printing your own, you may want to first print the document from your browser, so you get a decent copy to view, then do a "search and replace" for the ASCII hard return character and replace all but those where you want a blank line separating paragraphs or ideas - then "save as" a different file name for use by your word processor.

- - - - - - - - - and now, "the document" - - - - - - - - - - -

"SUBASSEMBLY 3 THE RUDDER"

"The rudder and elevators of the RV-6 are quite different than the surfaces you have built up to this point. Instead of having internal ribs to support the skins, there are ribs only on each end. Stiffeners, made of aluminum angle and riveted to the skin (but not the spar), help the skin keep its shape. The skins themselves are only .016" thick and are very easy to damage through careless handling. Laying a rudder or elevator skin on even a small drilling chip or other piece of debris can result in a dimple that can't be removed. Gripping an edge too tightly or lifting the skin from one end can cause an unsightly crease. Handle these skins with care: lift them from both ends and always keep the surfaces you lay them on spotlessly clean."

[ Moved the next paragraph, "It is important to align the skin and skeleton carefully . . ." and the entire next section, "THE CONTROL SURFACE JIG" with its two paragraphs so as to appear in a better sequence, i.e., as first paragraphs of the section "JOINING THE RUDDER SKIN TO THE SKELETON".]

"FITTING THE STIFFENERS TO THE RUDDER SKIN"

(Added:) Remove all of protective plastic from inside of R-601PP rudder skin; on outside, peel aft from "leading edge opening" to about an inch behind the spar holes - cut off at this point.

(Added:) Mark "right" and "left" inside and outside of skin for help with orientation. We will lay out stiffener locations on "right" side first.

(Existing:) "Put the R-601PP rudder skin on your work surface," (added:) right side down, (existing) "trailing edge away." [Moved next two sentences to start new paragraph just before "Determine the length of the various stiffeners."]

(Existing:) "Cleco the R-602PP rudder spar to" (change "the" to "one side of") "the rudder skin. Mark the aft face of the spar on the inside of the skin" (added:) , and mark the top of the spar - later you will measure down from this line to mark location of stiffeners. (Delete: "This will give a reference for determining the length of the stiffeners.") (Delete "While the spar is in place, final drill the skin to the spar, then remove it." - this needs to be done later in the V-block jig.) (Added:) Cleco other side of skin to spar and remove clecos from first side, mark top and aft face of the spar on the inside of this side of skin, then remove spar. (Delete "Debur spar and skin.")

(Added:) Per Trailing Edge Detail, DWG 7PP, and the stiffener detail, DWG 4PP, draw a line parallel to, and 1/8 inch aft of, the spar web line traced earlier (both sides of skin); then draw a line parallel to, and 3/16 inch from, the trailing edge. The stiffeners will be cut to fit between these two lines.

(Existing, moved down from above, from being 2nd & 3rd sentences in first paragraph of "FITTING THE STIFFENERS TO THE RUDDER SKIN") "Refer to DWG 7PP for the position" (delete: "and length" - will discuss "length" later) "of the stiffeners on the inside of the R-601PP skin. They should be at right angles to the R-602PP rudder spar, NOT the leading or trailing edge of the R-601PP rudder skin." (Added) From DWG 7PP, note that the top stiffener on right side goes 5 1/4 inches down from line previously drawn at top of rudder spar - make mark on the "line drawn 1/8 inch from spar line". The other six stiffeners are spaced 5 1/2 inches. Mark all these locations on the "right side" skin, then cleco spar back on at ends and middle and use machinist's square held against spar and draw solid lines perpendicular from spar towards trailing edge at each of marks just made. Remove spar and use longer ruler to extend these lines between the 'line 1/8 inch aft of spar' to the 'line 3/16 inch from trailing edge". Make these lines solid, to represent where the 'side of angle perpendicular to the skin' will go.

After drawing all the solid lines, measure down 5/8 inch from each, re-install spar with 3 clecos, and draw dashed lines representing location of lower edge of stiffeners.

(Added:) Flip the skin over. (Existing, moved from above) "Remember to offset the stiffeners on (changed "one side" to "left side") as shown on DWG 7PP (This is done so that if a stiffener does make contact with the opposite side while making the final trailing edge bend, it will hit another stiffener, rather than crease the thin skin.)" (Delete "A good trick is to mark both sides of the stiffener, using a solid line . . ." because it was incorporated earlier.)

(Added:) The stiffeners on this second/left side will have the web side "down" (solid line) with the dashed line 5/8 inch above: From line previously drawn at top of spar, measure down 5 1/4 + 5/8" (width of stiffener) - 1/8 offset = 5 3/4 inches for the first solid line, then six more every 5 1/2 inches. Re-install spar and use machinist square to draw the 7 solid lines, then measure up 5/8" from these lines and make the dashed lines. Label each "stiffener outline" on skin, starting with #1 at top, to #7 at bottom - both sides.

(Added:) Now measure the length of each stiffener on one side, as they have been laid out, between "the line 1/8 inch from spar web" and "the line 3/16 inch from trailing edge" - write on skin by each line. Flip skin and measure stiffener lengths on other side & record as above.

(Added:) Inside each side of skin near trailing edge, at top and bottom, mark 3/4 inch from trailing edge (i.e., 9/16 forward of line previously drawn 3/16 from trailing edge) - connect the marks. Do on each side - this represents where aft-most rivets will go through stiffeners and will be used later to "eyeball mark" aft rivet hole locations on stiffener centerlines.

(Existing:) "Make the stiffeners from the AA3, .025 x 5/8 x 5/8 aluminum angle provided." (Added) Before cutting any long piece, remove the protective plastic from both sides of angle stock. Find your "2-tongue depressors" "flange marking tool", lightly clamp each piece of angle stock to edge of table and draw a centerline 5/16. The centerlines will be useful later in mentally keeping track of orientation as you lay stiffeners on skin.

(Added:) One way to set up for making the stiffeners is to clamp a small block of wood or metal about 2" long to the edge of the work table to right of where you are standing - use a square to make the left side perpendicular to edge of table. Then trace a line onto table on this side of the block and remove the block. Use a protractor and draw a 1" long line from the edge of the table at 15 degrees to the left of the block. Replace the block, again assuring it is perpendicular to edge of table. . . . .Measure 6" left of block and draw line perpendicular to edge of table.

(Added:) To make each stiffener, take a piece of angle stock, lay it on skin between lines marking its location, with side having centerline for future rivets on the skin. Label it "Right" (or "Left") "#7" (or "#6", 5, 4, 3, 2, or 1") near end closest to spar. This and centerline will help you keep oriented as you trim each end to its unique shape.

(Added:) Now lay the 18" ruler with its edge at edge of table and "zero end" butted up against the block clamped to table. Lay angle stock on top with "trailing edge end" against the block - mark the length. Set machinist's square to 1/2" and hold ruler part perpendicular to edge of angle with end of ruler almost touching radius of angle, at the mark for length - draw a line perpendicular to edge of angle all the way to radius of angle. Flip angle over and hold square so its ruler edge allows you to transfer the line from other side across this side. Use sheet metal shears and cut one side into radius, then flip and cut other side into radius and part will separate - ends will be very nearly square. Touch them up with sander or a file to make as perpendicular as you like.

(Added:) Now trim ends: Start with 15 degree cut on end nearest spar - lay angle on corner of table, butted against block, with side having centerline hanging down (vertical) so unmarked side is laying on table to be marked and cut - lay short ruler on top and to draw 15 degree line at end of angle. Cut along line. Next, set machinist square so ruler sticks out 1/8" and hold square's ruler vertical with 1/8" sticking out top, and lay angle with "centerline" side on square with "trailing edge" end of angle touching ruler - mark 1/8 up from "centerline" side. Lay that same end of angle on edge of table butted against block - make mark at 6" from trailing edge on side not having the centerline (use 6" line on table, or ruler). Connect the 1/8" mark and 6" mark, then cut on line with shears. Take to belt sander (or file) and round all corners, especially making the 1/8" radius at trailing edge end of stiffener, per plans.

. . . Next to last, if it is a stiffener for right side of skin, use round file to make small indentation at the end nearest the spar, on the side of angle that is perpendicular to skin (side without centerline). By marking only the right side stiffeners with a file mark (which paint won't obscure) you will keep the "right side" stiffeners separate from "left side" . . . . Last of all, lay stiffener in place on skin, accurately position end against "1/8" from spar" line, and then look straight down on "trailing edge end" and mark rivet hole location on centerline by visual reference to the "line 3/4 inch from trailing edge" as it goes under the stiffener. Stack stiffener with rest of right or left stiffeners. Make rest of stiffeners.

(Added:) Smooth edges of all stiffeners on Scotchbrite wheel.

(Existing:) "Mark" (delete "the centerline and") "rivet hole positions on the inside of the stiffeners (added) : Make a drill guide box by clamping scrap boards together to make a raised end and one side to hold stiffeners. Insert longest stiffener and clamp 18" ruler upside down to form 2nd side to hold stiffener. Slide stiffener about 1/8 inch away from end block/stop, transfer centerline to floor of drill box near the end block/stop, then slide stiffener back against stop and transfer centerline to that end of floor; remove stiffener and connect points to make centerline on floor of box. Find piece of scrap sheet steel to lay on top of stiffeners. Transfer centerline up from stiffener to end of steel on each end and connect end points. Lay out first hole 1/4 inch from "spar end" (end block/stop), then every 1 1/2 inches thereafter for total of 11 holes. Center punch all hole centers, taking extreme care to be accurate. Then drill each (#41), being extremely careful to be accurate. (Existing) " Because of the different stiffener lengths, the (change "nominal" to "maximum") "1 1/2 inch rivet spacing may not produce evenly spaced rivets. Evenly spaced rivets will require altering the spacing. A spacing may be determined (1 1/2" or less) mathematically, or by fixing the rivet positions at each end of the stiffener and using a rivet spacing fan similar to the one in VAN'S ACCESSORIES CATALOG" (added:) or piece of elastic with marks on edge every 1", which can be stretched between end holes to get equal spacing. (Existing) "It is perfectly acceptable to use the (change "nominal" to "maximum") spacing and alter the position of only one or two rivets. Either way, it is important that rivets at each end of the stiffener are in the position shown on the drawing. See Fig. 6-6PP."

(Added:) To use nominal spacing, lay in shortest stiffener, lay drill guide on top but slightly on edge so can see centerline on stiffener and holes in drill guide. Decide which will be last hole in guide to be drilled through for this stiffener - mark it with felt pen. Cut the distance between it and last hole in half and mark it on stiffener. Drill the stiffener. Repeat for each succeeding longer stiffener.

RIVETING THE STIFFENERS TO THE RUDDER SKIN

(Added:) Lay a piece of particle board on top of your work surface. You will drill through stiffeners and skin into this and install clecos through them into the particle board.

(Existing:) "Carefully clamp the R-601PP rudder skin to the table, position a stiffener on the skin and drill [added: (#41)] through the stiffener and the skin, into the table top" (added: or particle board cover). "Insert a cleco, directly into the table. Repeat until all the stiffeners are drilled" (added:) on one side.)

(Existing:) Remove the clecos, turn the skin over and drill the stiffeners to the opposite inside face of the R-601PP rudder skin. Be sure to properly orient the stiffeners. See DWG 7PP and DWG 4PP.

"Disassemble" (Added:) Use soldering iron on outer side of skin and remove strips of protective plastic from all rivet lines) "and debur the holes. BE VERY CAREFUL deburring the thin R-601PP rudder skin -- it doesn't take much pressure or over-enthusiasm to ruin a hole in .016 aluminum.

(Added:) Before dimpling, put masking tape over line of rib rivet holes at tops and bottoms of skin - not to be dimpled until drilled to ribs. (Existing) "Because .016 is too thin to machine countersink, it MUST be dimple countersunk. Using C-frame deep-throat dimpler/riveter shown in Section 3 is the recommended method. Whatever method you adopt, remember that the pressure needed to dimple .016 is quite low. Dimple the stiffeners (added: with pneumatic squeezer, if available) and skin" (added: with Avery dimple tool: Support skin on particle board that has been shimmed up so skin is level when bottom dimple die is up through hole in skin - only dimple holes for stiffeners and spar, not two ribs, since they have not yet been final drilled.) "The aft hole is quite close to the bend of the trailing edge and anything less than the most careful use of the dimpling arbor can result in a nasty crease. This may be the perfect spot for that pop-rivet dimpler. (Added after doing it: It was no problem.) It is helpful to use two bucking bars or other weights each side of a hole to be dimpled to hold skin down, one on each side of aft-most 2 or 3 skin holes to be dimpled for each stiffener; also shim skin under leading edge and elsewhere to keep flat as you dimple these trailing edge holes.

(Added/revised:) Clean & prime.

(Existing:) "After priming, you are ready to rivet the skin and stiffeners together. BACK-RIVETING is the best technique here. See Fig. 6-7PP. This is opposite of the usual practice of placing the rivet gun on the manufacutured head of the rivet and using the bucking bar to form the shop head. In back-riveting, the flush head rivets are taped in place with Van's Special Riveting tape (really. See VAN's ACCESSORIES CATALOG), mylar, Scotch 811, or similar tape (masking or regular Scotch tape does not work well) and placed head down on a bucking bar or steel plate. A small flat, cupped, or special sliding-sleeve set is used to make the shop head. If you are careful to keep the bucking surface clean, this method almost ensures clean, well-set rivets.

(Added:) Inset the steel plate into plywood or particle board. Plywood routes much easier/faster than particle board. Never use router inside your shop - use it outside so sawdust won't trash your shop!)

(Added:) Set air pressure coming out of tank to about 40 psi for riveting. Insert a row of rivets and tape over the flush heads. Turn skin over and insert a stiffener over rivets. Be careful to be on back riveting plate before setting each rivet. Hold free thumb down on stiffener as close as practical to rivet being back-riveted - to hold stiffener tightly against skin while forming rivet shop head. Finish riveting the stiffener, turn skin over, remove tape for re-use, and repeat the cycle for next stiffener.

BUILDING THE RUDDER SKELETON

(Added: Take R-606PP, R607PP, and R-608PP reinforcement plates and remove protective plastic. Debur prepunched holes and dress edges with Scotchbrite wheel or file.)

(Added:) Mark vertical centerline on forward face of R-606PP lower plate. With round file, make a small indentation in center of top, on side not flush to spar. Will establish orientation for assembly before drilling, and, being visible after painting, before riveting. . . . File small indentation in center of top, on aft face of other two plates (on sides not flush to spar).

(Added:) Draw vertical centerlines on forward face of R-405 rudder horn, on forward face of R-606PP plate, and on aft face of R-602 spar (through centers of predrilled holes). These are required later to align rudder horn and bottom rib perpendicular to spar before drilling.

"Cleco the R-606PP, R607PP, and R-608PP reinforcement plates to the R- 602PP rudder spar. NOTE that the R-606PP lower reinforcement plate goes on the forward (flange side) of the spar web, while the R-607PP and R-608PP plates go on the rear.

(Added:) Draw centerlines for rivets 5/16 inch from edge of each flange of R-404 bottom rib.

(Added:) Lay out notch in tab of R-404 bottom rib: Draw centerline on top web of rib, through centers of two tooling holes. Extend centerline onto tab. Measure up 1/4" from edge of tab to mark center of hole and drill with Unibit to 13/32, then draw lines tangent from each side of hole to edge of tab, parallel to centerline. Use shears and cut from edge to tangents of hole. Clamp simulated skins onto bottom rib, keeping clamps at least 2 inches from end of rib to avoid interference with rudder horn in assembly.

(Added:) Take the long rod end bearing, install a jam-nut all the way onto threaded portion, then insert through R-606 plate, spar, and R-405PD horn and install another nut to loosely hold the assembly, then slide R-404 bottom rib tab down between spar and rudder horn, and using simulated skins to center rib on spar - snug nut, then adjust rudder horn so it is perpendicular to spar centerline (centerline on rudder horn is visible centered in center hole of spar), and also hold bottom rib down onto top of rudder horn as nut is snugged down to hold assembly. Rib web should be perpendicular to spar centerline - check with machinist square vs the previously drawn centerline, then carefully trace rib's web across spar (or, if parts are too wiggly to also handle a square, hold the rib down against rudder horn and make single mark on spar web at center of rib's web, then later use square to draw a line through this mark perpendicular to the spar's centerline. Will use this line later for visual check before and during drilling of assembly to spar.

(Added:) Disassemble, then hold rib against spar at the location just marked and trace the tab onto the spar. Now draw a line about 1/16" below tab's outline and measure down to the bottom of spar (record on plans and on spar) then measure nominal width of spar below that line (and record). (Added:) Take piece of spare .032 sheet and cut out a spacer. It will later be assembled below rib tab, between spar and rudder horn before drilling everything together. Remove protective plastic and finish edges with Scotchbrite wheel or file. Make small round file mark at top on side not touching the spar, for orientation when re-assembling after painting.

"Ensure that the R-404 bottom rib and R-405PD horn are perpendicular to the lengthwise centerline of the R-602PP spar" (added) by checking rib web aligned with line perpendicular to spar centerline and by checking rudder horn's centerline is centered in bottom center hole of spar. Clamp assembly SECURELY at bottom with visegrip clamp(s). "Drill" [added: (#30) and cleco ] "the" (added: top and middle) "reinforcement plates and the assembly at the bottom of the spar, using the holes in the spar as a guide."

(Deleted next 3 steps: "Clamp the R-404 rib . . .", "Disassemble the spar . . .", and "Rivet the spar, . . ." REASON: Drilling of top rib's tab to spar, and skin to spar will be done later in V-block jig. Replace with the following:)

(Added:) Take R-403 top rib and draw centerline across aft face of end tab 5/16 from edge. Measure in 5/16 from each side and mark centers of two rivet holes. Draw centerline for rivets 5/16 inch from edge of each flange.

(Added:) Mark approximate location of top rib on aft side of spar by measuring down 5/8 inch from top per DWG-7PP. Use machinist square and draw perpendicular line across spar at this location. Clamp top rib to spar at this approximate position. Do not drill to spar at this time - will be done later in V-jig. Lay skeleton aside.

COMPLETING THE TRAILING EDGE OF THE RUDDER

"As supplied, the trailing edge is not bent to its final shape so there is easier access for drilling and riveting the stiffeners. Before you join the rudder skin to the skeleton, this bend must be completed. Simply pulling the skin down on the sides of the skeleton and fastening it results in a trailing edge of the wrong shape. DO NOT DO THIS!! IT WILL ADVERSELY AFFECT THE FLIGHT CHARACTERISTICS OF THE AIRCRAFT!!"

"Fig. 6-3PP shows a simple wood "brake" used to bend the trailing edges of control surfaces. Make sure the faces are clean and smooth." (Added:) Bending brake must be long enough to handle 41 inch rudder, 43 1/2" elevators, 47 3/4 ailerons, and 55 1/2 inches flaps.

(Added:) Before bending, tape a 1/8 inch dowel inside trailing edge radius. They come in lengths of about 36 inches, so get two. Dowel may be held in contact with trailing edge by clamping and/or duct taping pieces of 1/8 inch scrap (or 2 tongue depressers) butted perpendicular to the dowel. . . . Check that 1/8 inch dowel will slide loosely past ends of stiffeners - if any stiffeners are long enough to grab the dowel when skin is folded closed to fit spar, then carefully trim the ends of the offending stiffeners. This 1/8 inch dowel will later be installed before applying RTV to ends of stiffeners and riveting the skin to the skeleton, so there will be a drain hole through each blob of RTV when the dowel is pulled out. If the stiffeners are too long, you won't get the dowel out without gouging it. No RTV goes in this area at this time - wait until just before riveting skin to skeleton.

IMPORTANT: "Insert the R-601PP rudder skin so that the trailing edge is about 1/8" from the hinges and gently squeeze the skin. You will be able (added: to) feel the trailing edge compress. Bend the skin until it just touches the R-602PP spar when the bend is finished... it will be necessary to "over-bend" the skin slightly for the finished bend to end up correctly. Fig. 6-8PP shows a correctly finished rudder. The skin is flat and straight from the spar web to the beginning of the radius of the trailing edge. It is important to avoid tapering or bulging trailing edges."

(Added:) It may be helpful to do about half of the required bending, then flip skin over and finish the bending - compensates for any irregularities in bending brake.

JOINING THE RUDDER SKIN TO THE SKELETON

[Moved text from pages 6-8 & -9, to here, i.e., 2nd paragraph and the next section "The Control Surface Jig"]:

"It is important to align the skin and the skeleton carefully before drilling the holes for the rivets that will join them, particularly along the spar. The rudder (and elevators) must be symmetrical around the chord plane, without any twists or bows. The jig below provides a simple way to align the structure, and serves as a convenient "holder" for the rudder assembly during drilling and riveting."

"THE CONTROL SURFACE JIG"

"The rudder is best assembled in the "V-block" or "cradle" jig shown in Fig. 6-3PP. The object of this jig is to keep the rudder straight by holding the lengthwise centerline of the tapered spar and the bend line of the trailing edge in the same (chord) plane."

"The jig shown is designed to mount on a flat, level surface. This means flat and level... if it is not, the jig can build a twist into the part. If the available surface isn't good enough, it is possible to shim the jig so that it aligns properly, using a good carpenters level. Fig. 6- 3PP shows the cradle mounted on a worktable, but the crosspiece of the empennage jig or any level, flat surface will do. Attach a 2x4 reinforcing block" (added: with true 90 degree angle between its bottom & vertical face butting against V-block, if possible) "to the bottom of each V-block with" (delete "glue and wood or") "drywall screws." "Mount the V-blocks on the table (the correct distance between them is shown on DWG 8PP.)" . . . . . . . . (Added:) Don't use this distance if it is still 39 1/2 inches on your drawing. Rather, use a shorter distance of 35 1/2 inches so top and bottom rib rivet holes are accessable for drilling and riveting. Be careful that V-block is perpendicular to table before and after attaching 2X4 reinforcing blocks - shim if necessary.

"The V cuts in the blocks have intentionally been left unfinished. Draw a centerline the length of the wedge, through the tip of the angle and continue it to the foot of the block. Complete the cuts with a handsaw, carefully keeping the saw to the outside of the existing saw kerf, then replace the wedge in the groove. Align the centerline on the block with the line on the table. Use a square to assure that the block is perpendicular to the table surface and square to the line. Use screws or angle brackets to fasten the blocks in place. When you are finished, the V-blocks should be square to the centerline on the table and perpendicular to the tabletop, parallel to each other" (added: (measure distance between tops and bottoms - should be equal) ", and firmly attached. Additional stiffeners of 1x4 or light metal angle may be nailed along the sides to connect the endpieces and stiffen the cradle. Remember, the rudder can only be as straight as the cradle." (end of text from pp. 6-8 & 9)

"Mark" (added: 5/16 inch flange) "centerlines on" (change "all" to "both") the ribs" (added:) if not previously done. "Install the R-601PP rudder skin in the V-groove jig and place the rudder skeleton inside it. Cleco the skin to the (change "skeleton" to "spar") and (added: clamp) the ribs so the centerlines are visible through the holes in the skin."

(Added:) Recheck top rib's flange centerlines visible on both sides - then use long #30 drill up through marked hole centers through rib end tab and through spar. Cleco after drilling each hole and recheck that flange centerlines are still aligned in skin holes.

(Delete: "Clamp the skin and skeleton together with spring clamps and begin drilling.") "Drill [added: (#41) ] the entire skin to the skeleton using clecos every other hole" (added:) i.e, both ribs and spar."

(Added:) To minimize oil canning (which may not even be a problem on the rudder, but is on all elevators), drill and cleco the ends of the spar. Now, if skin doesn't lie flat on spar, but bulges up a bit, then divide the bulge in half at the center of spar and cleco. Now go half way either side of center and cut the bulges in half and insert a cleco at each "1/4" point, then continue subdividing the bulge as you cleco. Now drill and put a cleco in every hole, in that same sequence. Now drill each rib to skin, cleco'ing as you go.

(Added:) Check for interference of R-405PD in slots in skin. Trim and re-finish trimmed edge of each slot if necessary.

(Delete entire paragraph starting with "Fit the R-410 rudder horn brace between the R-405PD and R-404." Replace it with the following:)

(Added:) Trim the sides of R-410 rudder horn brace (new model being shipped by mid-1998 that fits properly and has lightening hole in it and has 3 holes pre-drilled in aft tab) along dotted lines marked at factory.

(Added:) Remove 5 clecos from each side of R-404 rib (#2, 3, 4, 5, & 6 from spar). Hold the R-410 in position and mark location of its forward tab on R-405PD rudder horn. Lay R-410 aside and draw a centerline across R-405 5/16 from edge for 4 rivet holes (per DWG 7PP note). Two end holes are 5/16 from sides of tab and two middle holes are equally spaced. Clamp R-410 into position and drill (#30) and cleco the holes in both tabs. Drill (#41) through holes in skin and bottom rib flanges into R-410.

"Make the rudder bottom attachment strips shown in Section A-A' of DWG 7PP." (delete: "and clamp them in place.") (Added:) Make these 15 X 1 1/8 inches from .032 sheet in "trim bundle". Draw one line 1 1/8 inches and another 1 1/4 inches from an edge of sheet from trim bundle. Do initial cut at 1 1/4 inch line and final cut at 1 1/8 line. Cut off one corner at an angle - on a line connecting points 13/16ths from end along long side, 9/16 down from long side on end. Remove 13 clecos from bottom rib/skin and clamp them in place for trial fit - mark through end rivet holes, then remove and assure 3/16 min edge distance. Finish edges with Scotchbrite wheel or file. "Drill them [added: (#41)] to the (change "skeleton" to "bottom rib"), using the existing holes as drill guides."

"Disassemble the rudder and debur all the holes" (added:) and edges. "Dimple the skin, spar," (added:) rudder bottom attachment strips, R-410, "and ribs. Although the rudder and elevator spars are .032 and could technically be machine countersunk, we strongly recommend that these parts be dimpled. Be careful that the dimple dies do not drag along the web of the spar and gouge it. It may be necessary to grind a flat side on the dies to obtain the necessary clearance."

(Added:) Lay out and drill corner holes in R-405 rudder horn per Dwg 7PP, upper right corner. 1/8" means 1/8", not the #30 drill you've been using which is one step larger than 1/8".

"Prime all components desired, including the K-1000-6 nutplates." (moved here from earlier location).

". . . reassemble (added: skeleton) with clecos." (Added:) Remember the cleco'ing sequence if your skin doesn't lay perfectly flat (which would cause oil canning after completion).

(Added:) Set air pressure back up to 80-100psi. Rivet top rib to spar; top and middle spar reinforcing plates and nutplates (two -5 rivets using 2 thick & 2 ultra-thin washers on squeezer, then two -6 rivets on platenuts using 2 thin & 2 ultra-thin washers; and lower assembly: R-606PP plate, R- 405PD rudder horn, spacer, bottom rib, and nutplate - use -8 round head rivets for lower plate nut - plans call for flush rivets, but that is only if install platenut to R-405 before assembly to spar and other parts of that lower assembly. Round head and doing all at once saves time by not having to countersink for flush rivets.

(Added: Rivet the R-410 box to R-405PD horn and R-404 rib web - but NOT to rib flanges at this time.)

(Added:) Set up squeezer for -3 flush rivets in skin: 1 thin washer with "perfectly flat" set from Avery (1 thick and 1 thin set).

(Added: Coat your 1/8 inch dowels with liquid dish soap so RTV won't stick to it, slide them in trailing edge before RTV - hold in place with tape and tongue depressors or scrap. Dowel will later be removed, leaving a drain path down trailing edge through RTV.)

"Place a fingertip size daub of RTV compound inside the trailing edge of the rudder skin at the end of each pair of stiffeners. (Permatex UltaBlue, p/n 77B is suitable and is widely available in auto parts stores. The fuel tank sealer ProSeal is also good if there is a RV builder near you who has some) Spread the RTV so that it adheres to the end of the stiffeners and fills the trailing edge of the skin. This will help absorb vibration and help prevent possible cracking."

(Added:) Go to hospital emergency room and get 12 inches of natural rubber surgical tubing, go to hardware or lumber store and get a 3 foot length of 3/16 inch solid metal rod, make a 90 degree bend 12 inches from end of rod, then saw off about 4 or 5 inches from the bend to make a handle. Measure up 3 inches from "exit end" or "bottom end" of tubing, make a clear mark with felt tip pen, insert tapered RTV applicator into that end and slowly squeeze RTV to fill the bottom 3 inches, then insert 12" metal rod into top end of tube for a piston, slide the lower end of tubing down between a pair of stiffeners until it bottoms out near the trailing edge, and slowly push down on the 3/16 rod/piston to expell the RTV - give you almost 100% control of where the RTV goes. Use the tip of the tubing to mash down on either side of pair of stiffeners to get RTV all the way to the trailing edge. Repeat for the other pairs of stiffeners. "Immediately reinstall the rudder (added: skin) in the jig (added: , cleco skeleton & bottom strips in,) and rivet the skin to the skeleton (added: starting with the spar - start in middle and work up and down - or in the pattern you used to cleco to prevent oil canning; then top and bottom ribs.) A rivet squeezer will reach almost all the rivets, depending on the throat depth. Be careful. If holes have been drilled too close to the rib or spar webs, the rivet set may gouge these webs while squeezing the rivet. A set may have to be ground flat on one side to avoid this. In the narrow spaces at the end of the ribs a narrow bucking bar will be necessary. If one isn't available, MK-319-BS blind rivets may be substituted for the last one or two AN rivets."

. . . (Added:) Orndorff video said use MK-310-BS blind rivet for first rivet on bottom rib closest to spar, after opening hole up with 7/64th drill; then use CS-4-4 pop rivets for next 3 rivets if can't reach with squeezer for AN rivets. For trailing edge rivet on top and bottom ribs, Orndorff uses a very narrow "no hole" rivet set yoke on squeezer.

. . . (Added:) David Carter used a big wood splitter wedge with sharp edge filed flat and clean, with small piece of duct tape to cover blade and corners to protect painted surfaces and bucked on the shiny surface of the blade - it fits all narrow spots. Can do the same thing on one of Avery's bucking bars - there's a narrow "blade" like surface at opposite end from one normally used, that can be filed clean and used just like the wood splitter wedge, and it is better - better hand hold and control.

COMPLETING THE LEADING EDGE OF THE RUDDER

"Before the rudder can be installed on the vertical stabilizer, its leading edge must be formed. The object here is to achieve a smoothly curved surface that fits neatly between the skin overhang of the stabilizer. Simple pulling the overhanging skins together results in an angle or crease where they cross the edge of the spar, so the curve is started by rolling the edge of the ruder skin. You will need a piece of 3/4 or 1" steel water pipe, a broomstick, or something of similar diameter, about four inches longer than the skin."

"Place the rudder in the V-groove jig (added: or on flat table - Orndorff video). Tape the edge of the skin to the pipe along its entire length. (Added: Some builders find it easier to bend each of three sections separately.) Use vise grips or small pipe wrench clamped to the pipe as a handle and roll the skin around the pipe. Keep pressure down toward the work surface and away from the spar to keep the skin from bending right at the spar. This will not produce the final shape, but it will produce a curve in the skin that allows the skin to be closed with a minimum of spring back pressure. Fig. 6-9PP illustrates the process."

(Moved up - do before bending:) Drill the holes full size (#30) then clean up the holes. (Delete: "(it is hard to get to the inside of the curved skin with a deburring tool, but in this case a quick rub along the holes with a scotchbrite pad is good enough)"

(Added: Use edge rolling tool - or hand seamer - to put slight "downward" bend on top/overlapping skin.)

"Put the rudder back in the V-groove jig (added: or flat on table) and finish the bend by hand, squeezing the skin until the holes match. (Added:) Cleco all holes, then remove one cleco at a time, starting in middle of a section ". . . and rivet. Blind rivets are used for the first time here. They are simple to set with a hand pop-riveting tool, but they are difficult to drill out. Make sure that the heads of the rivets are firmly against the rudder skin before squeezing. See the Rudder Leading Edge Detail on DWG 6PP." (Added:) Also, make sure the removable tip on the rivet puller has the smallest hole that the rivet nails will fit into - it probably won't come that way from the factory.

"Except for the fiberglass tips (those come after all the empennage surfaces are built, so you may do them all at once) the rudder is finished."

(Added: The rod end bearings must be screwed into the platenuts the correct distance and the rudder trial fitted to the vertical stabilizer. Make some tools first: Buy thick wall 1 inch OD PVC pipe (6 inch and two 5 inch pieces), a T, a coupler, and small can of PVC pipe cement. Make a "rode end bearing socket wrench" per Sam Buchanan's photo's and instructions at http://www.ath.tis.net/~sbuch/rv6/. From the left over 3/16 rod you just bought for your RTV piston, make two "temporary hinge pins" to use with rudder and later with elevators. Mark 5/8 (or 11/16) from end, taper 1/8 (or 3/16) of end to facilitate insertion into hinge brackets and rod end bearings, carefully polish the full 5/8 or 11/16 end until it will barely slip into the hinge brackets (previously cleaned out by inserting a 3/16 drill bit shank into each hinge pair to clean out paint), put 5/8 (or 11/16) of end into vise, hold some round object at edge of vise to help make a radius and pull on the rod to bend it 90 degrees (making a handle), then about 45 degrees beyond. Remove it and put a 45 degree bend in handle just above the 5/8 "pin" part so handle comes up 90 degrees from "pin" part. These bends allow the pin's handle to clear the skin close to each rod end bearing.

. . . Screw the top rod end bearing (with jam nut screwed all the way on) in until it's bearing hole centerline is 13/16 from spar, screw the middle rod end bearing (with jam nut all the way on) until it is 14/16th (7/8th), and the bottom rod end bearing (withOUT jam nut) until it is 15/16ths from spar. There are 24 threads per inch so it takes 3 turns to make a change of 1/8 inch depth. Now turn each one back out 1 full turn.

. . . Trial fit rudder to vertical stabilizer to check for 2" between spars at top of rudder skin and 2 1/2 inches at bottom of rudder skin: Make two more tools: Two pieces of wood whittled to a slight taper to carefully and slightly spread the hinge brackets apart so rod end bearings will slide in. Lay vertical stab on table (or bed), lay rudder next to it with rod end bearings touching hinges. Spread bottom pair of hinges and slip rod end between the hinges - slide a 3/16 drill bit shank in to pin the parts together. Now go to middle bearing and use tapered wood to start that rod end into hinges, and then top rod end into its hinge. While holding the rudder in this position, start end of a "temporary hinge pin tool" into one side of hinge, and use other hand to move rudder slightly to align hole of rod end bearing so "hinge pin tool" will slide all the way through and show slightly on other side. Then pin last hinge.

. . . Measure distance between spar webs at top (2 inches) and bottom (2 1/2 inches) When satisfied, carefully unpin rudder and store parts. Go build a right elevator.

Carter's filename = c:\wp60\projects\aviation\buildrv6\html.rud