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DavzLSA progress

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  • #16
    Hi Bill, that is one reason, it makes for a tighter cowl and it has the advantage of stopping any air leaks.


    • #17
      Hi Guys, I have more progress to report. I have built my horizontal stabilizers and elevators. Nothing remarkable about that. But I did deviate from the plans. I did not like the bg gap the hinges on the plans left between the rear spar of the trim tab and the rib in the elevator. So I used the tube rear spar of the trim tab as a hinge point. I welded some bushings in the adjacent ribs along side the trim tab and used pins to hinge the rear spar tube. I dont know if it is lighter but I think it looks better. I checked with Bob before I did it and he said I could do it.Anyway I have included pictures.
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      This gallery has 6 photos.


      • BTAZ
        BTAZ commented
        Editing a comment
        It looks Good!

        My only concern is whether you will have enough clearance for five layers of fabric.(top piece overlapping the bottom plus a tape on the elevator, one layer plus tape on the trim tab)

      • Bdflies
        Bdflies commented
        Editing a comment
        I like the clean look! I've looked at these pics several times and still haven't figured something out. How will you put the hinge pins in place, when everything is covered?


    • #18
      HI Btaz, I did not even think of that. I guess Ill find out when I go to cover them? I think Ill be OK though because the gaps are not as tight as I wanted them to be. Now im waiting on my lathe and mill get get here so I can make ail the machined parts, my son is a machinist so im going to out him to work.


      • #19
        HI Bill, The plan is to cover the trim tabs first then install them with the pins and cotter pins through holes drilled in the pins and the bushings, then cover the elevator. Im figuring this out as I go so Ill let you now how it goes.


        • Bdflies
          Bdflies commented
          Editing a comment
          I'm pulling for ya!


      • #20
        Do you intend to use Oratex?

        I think it is going to be tough to get paint down in that gap area wth the trim tabs in place.

        Maybe you can cover right over the gap area with fabric tape left slightly loose so as to not prevent the hinge movement.


        • #21
          Hi Bill thanks for the encouragement. Its all just one big adventure building an airplane, I think that is why we do it? Hi Btaz I was thinking of using the stewart system for the covering system. As with many things with this project im just learning as I go. Ive never covered and airplane before so im looking forward to learning to use the stewart system. As a matter of fact I will start with the trim tabs. Worst case scenario I will have to rebuild the elevators or trim tabs and I think I could do a better job the second time around because I now have practice!!! What do you guys think about the stewart system? Have any of you ever used it?


          • #22
            It is great to see your progress.

            It was my first time covering too and I ran into a couple "clearance challenges" due to fabric build up which is why I asked.

            Oratex is already colored so the painting challenge I mentioned wouldn't be there. However, their glue is set with heat so I don't know if you could get the glue set down in the trim tab to elevator gap.

            I attended both the Stewart's and Stits seminars at Oshkosh last year. The Stewart's was much more in depth and I was leaning that way until a friend of mine gave me his leftover Stits supplies and fabric which tilted the financial consideration to Stits.

            When I was researching, the thing that was always driven home was that Stewarts is not forgiving of even the slightest deviation to their application process and the issues caused may not show up for a year. So the overriding guidance was to do everything EXACTLY as instructed with very particular attention to any possible contamination in your air system or on the surface you are painting. While that can be the same for all of them, I know the Stits coatings(I used Poly Tone) was much easier to spray without runs or orange peel then the automotive urethane I used on my wings.

            And now that I think about it, during my research, there were plenty of complaints about Stits smelling bad and that MEK is "Nasty stuff" but I never saw one about "All my paint is bubbling off " of which there are several Stewart accounts.

            Also, just because Stewarts is waterborne, it is not really any less toxic to breathe then the other paint systems, though not as bad as a urethane based system that really requires a fresh air breathing system.

            Stits does smell BAD and there are lots of coats to apply. But it was pretty straightforward to use and easy to spray without too many "oops".


            • #23
              Hi Btaz thanks for the advise. I am now second guessing my decision to go with the Stewart system. Maybe ill look into the Oratex system? Since you have researched all the different systems which one is the most economical? I don't mean cheap by most economical but which one do you think is the best value for the money? I'm a long way from covering but I am closer to sand blasting and painting my fuse tubing and I want to be sure to use a coating that will be compatible with the covering system I'm going to use. I know that the Stewart system has a recommended coating for the tubing before applying the fabric. I also wanted to tell you that I like the way you figured out how to set the elevator control horn angle. I think I will mount my horizontal stabs and elevator vertically to get them mated to each other and set the control horn angle. Its hard to beat gravity to hold things in line? If I get the tail feathers in line like that, it will be easier to get the correct incidence angle when I mount them to the fuselage. I finally pulled the fuse out of the jig and turned it on its side so I can weld up the bottom and parts I could not get to while it was in the jig. I bought gear legs from Mark so once I get the fuse welded up I am going to attach the main gear legs. I have matco wheels and 21 inch desser tires. What did you do about flying wires? Did you buy some or are you using the ones in the plans? I'm considering buying flying wires because I have heard about the ones in the plans breaking. I think it would be a bad thing to lose a horizontal stabilizer in flight? I also wanted to ask how you did your seats. Did you use plywood under the cushions? What type of foam did you use? I am also thinking about changing the trim handle position. I think I am going to put a lever under the throttle quadrant on the side of the cockpit. I even thought about using a wheel but I think the lever under the throttle quadrant would be easier.


              • #24
                My opinions(which may be completely wrong)

                I really wanted to use Oratex for the possible weight savings. However, I just wasn't willing to spend the $3500 to $5K I saw for the material estimate given I already had most of the "capital equipment" items and facility available. I already had a decent compressor and air system and I was comfortable setting up my garage as a paint booth. I did need to buy a good quality spray gun(a DevilBiss FL4 for about $200) and spent a bit of time learning to set it up.

                Note even if you don't need the tools/space for the covering because you used Oratex you will still likely need them to paint the wings and boot cowl forward.

                As mentioned, my only "training" was the Stewart and Stits seminars at Oshkosh last year. I came home undecided but leaning toward Stewarts as they have a very good set of online videos that "spoke well" of their commitment and support. I was nervous about some of the "bad experiences" I had read about but they all seemed to stem from a lack of attention to detail when using the process(contamination of the air supply or surface, not thinning precisely, not adhering to drying time restrictions between coats, poor spray gun set up, etc.).

                I primed my sandblasted fuselage with the Stits Epoxy primer as I was confident it would work with any of the covering systems which allowed me to delay my decision even further.

                But then I was given some fabric, PolyTack, and the Stits covering book(absolutely invaluable and a must have) and away I went. In the end. I think I have about $2K in the covering.

                Even at the end of it I am certainly not a master painter but I found the Stits coatings pretty run tolerant and not subject to the issues I had with orange peel in the urethane used on the wings. Even with my inexperience over the 10 or so coats(2 sprayed Poly Brush, 3 cross coats(6 coats) of Poly Spray and 2 coats of Poly tone) of various chemicals needed I only had one very small run.

                I posted a "Covering notes" entry on the forum that gives a bit more information including chemical quantities and some other notes.

                Regarding the wire ends, I made them and feel that if they are made correctly(hot forged and hot bent, annealed at the end of the process, inspected for cracks in the bend before sandblast and paint) with attention paid to get the bends correct and the attach bolts tightened correctly so there isn't any misalignment with the flying wire my opinion is they should be fine. That said, I expect there are plenty of ways to make/install them wrong(adjust the bend cold a few times, let them twist slightly wen tightening the attach bolt, etc.)

                But I'll see in a few hundred hours.

                I covered the seats with fabric and it seems to be working fine. I am just now adding some tempur foam cushions and a seat cover.

                I am fine with the trim on the ceiling and don't feel moving it would be an improvement. It is pretty easy to adjust blind.

                If using pre-welded gear legs, you will want to jig them in alignment to the fuselage before welding on the attach brackets.

                And yes, "Which way is precisely down?" is one of the best engineering standards available.

                I left you my phone number in a PM if you want to call and talk.
                Last edited by BTAZ; 06-08-2017, 11:33 AM.


                • #25
                  Hi Btaz thanks for responding to my questions, sorry about hitting you with so many at one time. This airplane for me is a retirement project so im not hurrying to get it done but I constantly think about it hence all the questions. I have seen a Bearhawk LSA in person but it was a quick build kit that was already covered. So it was not very helpful in seeing how things went together. I got your number and I intend to call at some point in time when I hope it will be convenient for you.


                  • #26
                    Different Strokes! I used Stits poly process, here are the result for what it's worth! Stinger
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                    • #27
                      Hey Stinger that looks really good, I like the yellow strip. Are you planning a military paint scheme? I have considered that but Im a ways off from that. It looks like a factory job. Good work.


                      • stinger
                        stinger commented
                        Editing a comment
                        No, not military this time. American Indian theme is what I am shooting for the aircraft is Lil Bear . Stinger

                    • #28
                      That would look cool with a dream catcher somewhere. I always liked Native American art.


                      • #29
                        Progress to report, finally got all the finish welding done on the fuse, I am now fitting the horizontal stab, I have it and the elevators built. I ran into a problem in that the top longerons were too close together to allow the elevator horns to move up and down without hitting the longerons. So I ended up cutting them from the tail post and spreading them out so that I had 2 inches between them at 5 inches from the tail post per the plans. I think I got them too close together when I initially welded them to the tail post.


                        • #30
                          Adapt and overcome!