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    Super Blanik

    To be frank, I was never too fancy over the Super Blanik L23 look over the years. I was facinated by the modern class composite scale gliders. Only during the recent years, I came across some detailed 3-views of the older built-up wooden and metal gliders that enticed me to design and build the Pilatus B-4, which I love a lot.

    During the last few months, I have been aerotowing small sport and semi-scale gliders with my Freedom 20 tug and I thought of trying it out with my semi-scale Swift S-1. However, it is designed primarily as a slope soarer and with the higher wingloading and ever-growing trees planted along the PFW, I feel that I'll need a much lighter glider for the job. Not just that it'll be easier to be towed, it should be light enough for thermalling, I hope.

    I always wanted to thermal a scale glider from aerotow but most commercial small scale gliders are pretty hopeless on thermalling due to thier higher wingloadings. The faster and cheaper production methods resulted in rather heavy airframes, which is better suited for slope.

    I want a lightweight small scale glider with aerotow release fitting and preferbly fix undercarriages as such it'll be aerotowed anytime. I also want it to be relatively quick build so that it'll not disrupt my B-29 build for too long. So I was searching for a good subject with lots of straightlines in the airframe which I can adopt conventional balsa built-up construction with the lightest possible airframe. I remembered the Super Blanik with has a straight forward fuselage section and simple tapered wings. The only special feature is that it has forward swept wings, but this does not pose much challenge for the build.

    I quickly drafted the plans out to determine the final size, which pretty much depends on the lengths of the available raw materials. I ended up at 76" full span, which the longest single member in the wings and fuselage is exactly 36" long.

    Last edited by joe yap; 24-11-2008, 07:33 AM.

    #2
    The fuselage has 1/8" thick balsa side panels glued straight onto the formers like a simple box construction. However, the turtle deck and the keel are 3/32" strip plank, before sanded to shape. The fuselage tail upper and lower sections are solid balsa carve to shape and hollowed out. The nose cone is built-up with laminations of 1/4" thick balsa, carved to shape before being hollow out with a power grinder. The aerotow release is epoxied permanently into the hole bored out at the extreme nose tip.

    Last edited by joe yap; 24-11-2008, 07:35 AM.

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      #3
      The wing joiner rod alignment holes are one of the trickiest part and I spent some time making a jig to help sighting the alignment. The holes are bored out with a sharpened brasstude with the jig.

      Last edited by joe yap; 24-11-2008, 07:36 AM.

      Comment


        #4
        I didn't take any pictures of the wing construction, but basically, they are very conventionally built. The wings TEs are sheeted with 1/32" balsa sheet and the ailerons are yet to be cut free and faced with balsa strips. One new feature I tried on this pair of wings is that I used Profili software to help me print out the transiting airfoil from HQ 2.5-11% at the root to HQ 3-9% at the tip, along with thier jigging tabs.

        The tailplane is also conventionally stick-built with 1/8" balsa to keep the wieght to the minimal. I try to avoid nose weight for Cg balancing for the model as far as possible.

        The rudder by now is partially done. It is basically 1/32" balsa skins with balsa ribs inside.

        I dry fitted whatever parts I have and take some picture for references. The AUW now tips at 10 oz, which sounds good for a sub 2 metre glider.

        Comment


          #5
          Hi Joe,

          I have a question:

          Why laminate 1/4" balsa to form a nose cone instead of using a solid balsa block? What's the difference in the process or final result?

          Also, for laminating a nose cone what type of glue do you use (to make the carving and sanding/shaping easier)?

          Thanks!

          Comment


            #6
            Originally posted by buckman View Post
            Hi Joe,

            I have a question:

            Why laminate 1/4" balsa to form a nose cone instead of using a solid balsa block? What's the difference in the process or final result?

            Also, for laminating a nose cone what type of glue do you use (to make the carving and sanding/shaping easier)?

            Thanks!
            If you use a solid balsa block, you'll need a bench saw to cut out the side and plan profile accurately. You also have to estimate the wall thickness during hollowing out with a dremel tool, as there are very little reference to take from.

            If you use laminations of balsa sheet, you can pre-determine the wall thickness by plotting the outlines of the inner cavity on each lamination. Furthermore, it is easier to cut a 1/4" balsa sheet with a sharp penknife than a solid balsa block. I use CA spreaded evenly for lamination balsa sheets.

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              #7
              Originally posted by joe yap View Post
              If you use a solid balsa block, you'll need a bench saw to cut out the side and plan profile accurately. You also have to estimate the wall thickness during hollowing out with a dremel tool, as there are very little reference to take from.

              If you use laminations of balsa sheet, you can pre-determine the wall thickness by plotting the outlines of the inner cavity on each lamination. Furthermore, it is easier to cut a 1/4" balsa sheet with a sharp penknife than a solid balsa block. I use CA spreaded evenly for lamination balsa sheets.
              Wow that must be a lot of CA used!!
              Go back in one piece to fly another day.
              Having fun yet?
              36.39mhz
              40.77mhz

              Comment


                #8
                Thanks Joe!

                Comment


                  #9
                  Joe,
                  When did you start the build?

                  Comment


                    #10
                    Originally posted by ammo View Post
                    Joe,
                    When did you start the build?

                    From the looks of the progress, I think he started before the planning, and build when we were sleeping!

                    Comment


                      #11
                      Originally posted by ammo View Post
                      Joe,
                      When did you start the build?
                      About 2 weeks ago, I started designing. I started to built only last week.

                      Comment


                        #12
                        Have been very busy with work and progress was slowed down. Nevertheless, the ailerons are cut out and finished. The left wing is covered and the tail parts are completed. The main wheel is installed and the wing root fairings are in place, less final shaping.

                        Comment


                          #13
                          Originally posted by joe yap View Post
                          Have been very busy with work and progress was slowed down.
                          Slowed down ? ...You're building at LIGHTSPEED ! ...compared to me ...I'm still struggling to find time to finish up my Talon.

                          Then can concentrate and build the "Joetug"
                          Seriously running out of ...Storage space !

                          Comment


                            #14
                            Tony,

                            You can consider converting an ARF to a tug plane. I saw SHS having a 30 size Pilatus turbo Porter which have povision for electric setup as well. I was quite tempted but I think would go for a bigger model for my next tug.

                            Comment


                              #15
                              Nah ! ...that would be an injustice to your gliders ! ...only a scratch build tug is good enough for your scratch build gliders !
                              Seriously running out of ...Storage space !

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