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    #46
    Finishing the stab. LE & tips are sanded to a knife edge. LE corners rounded.

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      #47
      Preliminary wing fitting. Templates were printed to match the airfoil at the point that it meets the fuselage. A thin coating of contact cement is used to adhere them to the fuselage sides. The wing opening is then rough cut.

      Trailing edges are attached to the center section of the wing. The fuselage centerline is marked, the wing aligned and trailing edge cutout marked, cutout and Tapered to fit the bevel of the fuselage.

      The wing is then trial fitted & the fuselage carefully matched to the wing contours. Be careful not to at too deeply. You want the LE exactly even with the hold down dowel holes in the forward bulkhead.

      Lastly the first trial fitting The rudder post appears to be very close to perpendicular to the wing. (more on that next time.)

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        #48
        Work on the Vertical fin. The plans show 1/4" sheet, but I'm going thicker, so I'm doing built-up & sheeted.

        1) I print out 2 copies of my plans so I can cut out parts. Again, I iron it between 2 pieces of wax paper so it's nonstick and mobile.

        2) I cut the bottom piece out by trial fitting, rather than from the plan.

        3) The back of the frame is measured by trial fit

        4) The plan is lightly sprayed with contact cement. The fin is framed up & thin CA'ed

        5) More trial fitting. The parts are gently sanded until a gap of exactly the thickness of the slab is achieved. (The reason will be shown, shortly.)

        6) The sheeting is cut, oversize, being certain to leave an extension behind the rear of the framing, thewidth of the rudder post on the fuselage. (Again, the reason will soon be revealed.)

        7) Why are we looking at a pile of marble tiles? I needed a perfectly flat way to apply weight to the structure while the Tite-Bond cures. I had some extras tiles left from a bath reno I did and figured they'd be perfect. Liberal amounts of Tite Bond are applied to one side of the frame and sheeting applied. One tile is placed, shiny side up, on the work bench, then wax paper, then the fin, sheeting side down. Tite-Bond applied to the other side of the frame. Then sheeting, wax paper, tile shiny side down an 2-3 more tiles for more weight.

        More when the glue cures.
        Last edited by JVESPER11; 09-27-2018, 07:44 PM.

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          #49
          Finishing tail feathers.

          1) After glue cures, the leading edge & tip are contoured. I like knife edge, but rounded is just as efficient. The bottom is squared off as well.

          2) Using a square, the vertical fin is mounted to the stab. Centered & exactly vertical is imperative.

          3) Trial fit. Note that the cavity behind the vertical fin's frame fits over the vertical rudder post.

          4) Note there is a gap between the bottom of the stab & the mounting surface. The rudder post is trimmed so that the slab meets the mounting surface.
          The mounting surface is trimmed so that the stab. is flat on the mounting surface.
          When the fit is correct, thick CA is liberally applied to the mounting surface, & the front surface of the rudder post. Nothing is done to the sides of the rudder post, until this glue is hardened. Then, thin CA is used to adhere the vertical fin's sheeting to the rudder post.

          5) Final check of the wing alignment. Stab & wing should be exactly parallel.

          6) Wing hold down dowels are prepared.

          7) Using my hand, only, turning counterclockwise, I use the holes in the front bulkhead, to mark the proper location for the wing dowels. Then, again using only my fingers, holes for the dowels,are drilled through the LE of the wing (clockwise, this time.)
          The dowels are then pushed in, to full depth. Followed by another, hopefully final, trial fitting.
          Then they are removed and a fairly large amount of epoxy is put in the holes and the dowels reinserted.

          8) Front wing mount completed.

          ​​​​​​

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            #50
            Wing mounting, continued.

            1) The plans show a hardwood block attacked directly to the 3/32" balsa exterior sheeting. Didn't sound very strong, so I beefed up the structure. I cut 2 pieces of ply and one piece of 1/16 " balsa to fit between the crutch and the wing saddle. The thickness, combined, should equal the distance from the sheeting to the inner edge of the crutch.

            2, 3) These are applied to the sheeting, ply-balsa-ply. The piece on the left is out from the wing saddle across the crutch. This is bonded to the pieces just applied and the inner surface of the crutch.

            4) The oft wing mount is a piece of 1/4" ply, cut and tapered to match both the fore & aft and top to bottom contours of the sheeting. To be sure that it was installed exactly even with the wing saddle, I placed a piece of waxed paper on the outer surface and screwed a piece of scrap ply, longer than the mount, to the mount. The mount is then installed using thick CA.

            5) After the CA sets 2 pieces of basswood triangle stock are tapered to match the sides and glued between the sheeting structure& the interior surface of the mount

            6) The locationthe mount is marked on the outside of the fuselage side and, from there, transferred to the top surface of the wing. Two holes are then cut through the wing, from the top surface of the wing, perpendicular to the Bottom surface. Sand these out to a tight fit for a 1.25" dowel

            7) Two pieces of 1.25'' dowel are cut, oversize, and sanded to match the top& bottom surfaces of the wing

            8) Trial fit

            9) Once properly fit, the dowels are epoxied in place.

            10) Once the epoxy has cured, any excess is sanded flush with the wing surface. The wing. is then carefully put in place and a 3/16" hole is drilled through the center of the dowel, and through the mounting plate. The hole should be drilled perpendicular to the bolton surface of the wing. The wing is then removed. A 1/4 × 20 tap is then used to tap the mounting plate. The 3/16" holes in the wing dowels is then chased with a 1/4" bit. 1/4 × 20 nylon bolts are used to attack the wing. Dubro offers 2 kinds. Black, with a hex head and white with a flat-head screwdriver head. I prefer the white ones as they are, while slightly harder to wslall, slightly oversize and far less likely to vibrate out.

            11) Beginning to look like an airplane!

            12) Checking alignment VS. stab & rudder. Looks about right.

            Comment


              #51
              Completing (nearly) the wing.

              1) Tip blocks are rough out from 1" balsa plank.

              2) The block is attached to the tip, using 6-minute epoxy 1-Ib lead ingots are used to hold it in compression, while it cures.

              3) The tip is planed & sanded to conform with the wing.

              4) The interior of the tip block is sanded perpendicular to the trailing edge.

              5) A Dlro hinge jig is used to Cut the hinge slots.

              ​​​6) Two 4" wide pieces of 2-oz glass cloth and two pieces 8" wide of 3/4 oz are cut. One piece of 2-oz cloth should be long enough to overlap the leading edge. Holes are cut to accommodate the hold-down dowels. This is to stabilize the balsa around the dowels.

              7) As the plane is electric, fuel proof is not an issue, I chose to use Helmsman spar varnish to adhere the glass to the wing.

              8) The varnish applied to the outer surface of the glass and squeegeed through to wet the balsa. Excess is left in place, temporarily.

              9) While still wet, the 3/4-oz cloth is placed atop the 2-oz cloth and squeegeed down. Add extra adhesive, as needed & squeegee off any excess. Repeat steps 8 & 9 for the other surface.

              10) While waiting for the varnish to harden, I cut and planed the ailerons into an aifoled shape. 1/4" balsa was used. The ailerons were cut 1 1/2" wide at the fuselage, tapering to 518" at the tip. The plans show constant-chord ailerons, that do not extend the full span. This was to control flutter. I use other techniques. First, the wingtip should always cover the tip of the aileron. Second, No linkages! Use one servo for each aileron and place it in the center of the wing panel. Direct pushrod connection to the center of each aileron. Lastly, taper the aileron. BTW: It's Lots easier to slot the aileron if you do it BEFORE you airfoil it .

              11) When the varnish hardens, trim and sand the excess glass. Ailerons are dry-fit.

              Comment


                #52
                Work started on the Nacelles. As I wanted room for my 5000 MAH,4S batteries plus 75 amp ESC's within the nacelle, I moved the body of the nacelle up, in relation to the wing. This required relocating the wing cutout.

                1) Templates were created (be sure to accommodate the slightly smaller airfoil on the outer side) and lightly adhered to 3/32" balsa

                2) The nacelle sides are then cut out.

                3) Each side is then traced, from the front of the firewall, back, onto 1/64" ply.

                4) The doublers are then cut out using scissors.

                5, 6) Laminating the doublers onto the nacelle sides. Again I used shiny marble bathroom tiles to be certain everything was perfectly flat. Tile, shiny side up, Waxed paper, balsa, glue, ply, waxed paper, tile shiny side down, and repeat. Then repeat. Finally 5-6 more tiles.

                7) While waiting for the tite-bond to cure, I cut out the fire walls. Find the center and lay out the bolt pattern for the motor mount. I used a small jeweller's phillips screwdriver and a tack hammer as a center-punch to be sure that the drill bit centers correctly.

                8) Firewalls cut & drilled.

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                  #53
                  Continued work on the nacelles

                  1) After the weights were removed, you should have 2 sets of mirrored nacelle sides. Each pair should have an inner (towards the fuselage) and outer towards the wingtip) side.

                  2) The external edges are matched. To do this, I lined up each pair of nacelle sides, matching the upper forward portion of the doubler. I then drilled 2 holes and bolted the two sides together, then CAREFULLY using a belt sander, I sanded all of the edges to match. Note that I did not do anything regarding the portion that fits to the wing. That is done REALLY CAREFULLY, using trial fits and a Dremel tool set to a very SLOW speed.

                  3) Finished side.

                  4) top and bottom notches are cut in the firewalls. The lower one will be for the ESC cables to the motor. Both are for cooling of the ESC and battery.

                  5) Attaching the firewall to the sides. After checking the doublers, yet again, for being square, using thin CA, I attached a piece of 1/4" balsa triangle to the balsa directly ahead of the doubler. It should be in contact with the doubler, but not on it. The firewall is then epoxied in place, pressed directly into the triangle and held perpendicular to the double, with a square.

                  6) Detail of the balsa triangle which serves to locate the firewall. If the washers at the base of the motor mounts are cramped by the triangle, it can easily be removed around the mount.

                  7) Both nacelles with firewalls attached. Both sides of each nacelle should lie flat, both top and bottom. This serves as the final squareness check.

                  Comment


                    #54
                    Attaching the nacelles. Like Dave Platt, on the original, I'm permanently attaching them, rather than making them removable.

                    1, 2) To leave room for the battery and connections, I made the bulkhead at the rear of the tank compartment extend only as high as the leading edge of the wing and moved the upper half to 1 inch behind the battery. Both bulkheads are positioned so as to allow them to serve as additional gluing surface.

                    3, 4) First, a narrower rear bulkhead is installed. Then the nacelles are CA'ed to the wing skin. The first bulkhead is glued to the leading edge. Then the sides, then the second and rear bulkheads. 1/4" triangle is then gently bent and CA'ed to the juncture of the wing & nacelle sides

                    5) A block is rough shaped & glued to the rear of the nacelle. It is then final-shaped to the contour of the remainder of the nacelle.

                    6) Awaiting the top, bottom and hatch.

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                      #55
                      Finishing the Nacelles.

                      1) Rails are glued to the inside of the nacelle to support the bottom of the battery compartment

                      2) Verifying room for the battery & E S C

                      3) The bottom of the NacelIe cut from 1/4" balsa. Undercut to conform to the contours of the underside of the wing. Edges are then rounded.

                      4) The Top rear of the nacelle is cut from1/4" balsa. 2 side rails are cut from 118" balsa and glued to the edges. These are merely to give a little more room in the battery compartment.

                      5) This is then attached to the nacelle and faired into the tail block.

                      6) The same procedure is used to create the hatch, but it is only tacked to the nacelle at the 4 corners to facilitate matching to the top rear.

                      7) Now it gets a little wierd. I mounted the motors, with the propshaft but not the prop plate washer or nut.

                      8) Normally I use 1/8" ply for the spenner ring, but I was out so I sandwiched a piece of3/32" balsa between 2 pieces of 1/32" ply. Ithen used a hole saw to cut out the rings. Use a hole saw at least 1/4" larger than the intended final size. (the size listed on the saw isthe EXTERNAL size.)

                      9) Dots are drawn to mark the intended diameter. Then a 1/4" bolt is placed through the center and a nut tightened.

                      10) I then chucked the bolt in my drill press and the ring turned down to final size. I use sand paper or a perma grit. A gouge would be massive overkill. be sure to remember the taper to match your spinner.

                      11) The center hole is opened just enough to allow the prop shaft to center it atthe point where it meets the sides. Using ammonia, to soften the sides, bring the sides in to meet the ring & CA it to the sides.

                      12) Scrap is used to create fillet pieces attached to the sides and the rear of the ring. The sides should be cut to allow the top & bottom blocks to fill in about 1/4" of the back ofthe ring. The fillets should leave no gaps around the circumference ofthe ring.

                      13) The top & bottom blocks are rough-cut and glued to the sides fillets , front of the top & rear of the ring.

                      14) The blocks are then rounded to match the top & ring

                      15) finished. The cowl is then cut .from the nacelle and the hatch freed. A smaller hole saw is then used to enlarge the hole in the ring, to make room for the collett styleprop shaft.

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