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Q for those using router method for cutting rib blanks---

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  • #16
    WOW---- thats one slickA@@ looking wing ! Thats probably one reason why its faster than cubs and champs ! Like that color too ! you look like you are ready to flight test ? see some paper on the side windows yet..... you must be close !

    The two ribs are just test pieces from unknown scrap to see if the tooling was going to work properly. The fluts are messed up there because I didnt have any spacer device to
    set a fixed distance from the bend line. Most all of the fluts there are into the bend line--- which seems to cause undue stress and distortion. I will fab up an adjustable spacer
    to "stand-off" about 3/16 off the bend line tangent. I think the whole thing will be happier that way. My REAL actual ribs should look better. Most of the warp came out when I
    pressed the fluts in.

    Im probably a reformed perfectionist. I grew up working in my dads machine shop- so I enjoy (sort of ) going to lengths to keep all the parts precice and similar dimentions
    and to OCD over stuff. I worked at an big FBO for a while. We had about 20 mechanics working--- and I was surprised at the variance of skills and craftsmanship across all
    the guys working there. Only 1 I wouldnt let work on my lawn mower. (!) Up untill then - I REALLY thought all those guys would have been just like me. apparently not.
    I also grew up restoring classic cars--- so maybe that helped some too. I think most of those were more work than restoring an airplane. (raw hours anyway)

    I may do what N3N (Mr. Snapp) did --- which was to add 2 layers of 1/8 spacer to the butt end of the cutting jig to be able to cut the 3 different rib lengths at the beginning. (or at least close--) As someone pointed out ---- you just adjust them on the the 90 degree mounting angle when they are riveted in. Probably better just a little short than too long. Hate to have to mess up the primer by cutting them off later.

    Reminds me-- gotta order eko-poxy next week !

    Thanks for the encouragement ! Your bird looks sweet. (what type engine by the way ? )

    Tim


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    • #17
      Hi. The airplane is complete. We are waiting for warm weather as it is currently -20 these days. We had it set for a fall Final. We had it running strong when it developed an issue with a fuel manifold divider regulator. The only part in the fuel system that we did not rebuild and it can be stupid crazy expensive. Once again Q1 Aviation saved our butts by rebuilding it at a fraction of the cost for a rebuilt exchange unit. The white on the rear window is the protective plastic on the lexan. We thought we would leave it on until the last minute. The protective layer broke down so we had to work it off bit by bit. The windshield was the worst. I think it would be better to get the plastic off the windshield sooner. Maybe put a piece flannel over the windshield to protect it & to keep it clean.

      I probably could give you a run on perfection but sometimes a person has to accept as good quality and move on. I read that perfectionists rarely finish and it can be true. The perfectionist cannot achieve 100% perfection so in the very dark corners of a perfectionist brain they reason reason that if they do not finish it the work that the work cannot judged because it is incomplete. It is good to pay attention to the details and do the best that you can. Set some perfection aside and go for quality craftsmanship. If the airplane is well built, safe and flying that is good. 90% of the work is covered 99% of the time. Bob Barrows bangs out an airplane every couple years that are good flyers but would not Oshkosh builder awards. Our airplane is a flying truck and we tried to keep it practical with an eye on reducing drag where we could. We welded out the fuselage and took it of the rotisserie. We set the fuselage in the table jig blocks and dropped the plumb bobs to find that it was almost dead straight with no distortion. Learn the process and what delivers the best results. Lots of good heads on the Bearhawk Forum that will give excellent guidance.

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      • #18
        The Divider sounds like something in the injector pump/servo. Sounds like you did gut lucky on that one. (pricewise)
        Yes- I dont trust that paper on plastic as far as I could throw a locomotive...... I bet part of the problem is that you never know how long it may have been sitting
        on the shelf before you got it. (paper aging)

        I have gradually figured out - as I have gotten older- how to "workaround" the perfection thing- (to a large degree) . Once in a while I still catch myself building a tool
        that takes me a week to build to do a job that takes 5 min. with the tool...... but would have all most impossible without the tool.

        I think I can cook along pretty fast making ribs once I "understand" the details of the tooling. What I have done so far a gone quite fast- considering I am just getting the last
        details ironed out.

        I am planning on using one of the factory tubing kits. I THINK I can weld up the basic joints (less the tabs) in about a month. I think that will be much quicker than the wings.
        ( I have gotten more efficient tig welding as I get to do it fairly ofter for work projects)

        Next i will be ordering green primer--- and a bunch more 2024 sheet.
        Got a sheet of barn rubber floor mat at Tractor supply to experiment with in the press for squishing the flanges. (just to see if it works better or worse than what I have)

        your place looks beautifull-- farm like---- hope to get a place like that if our place sells---- Im in florida and its all ready 80 here again and 65 at night.

        Hope you get a dead calm morning soon. Will you get to fly it out of your own property ? (that would be nice)

        Tim

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        • #19
          The flow divider is fed by the fuel injection throttle body that is a small pressure regulator that distributes fuel evenly to the 6 cylinders. It has a diaphragm that is lifted by the fuel pressure to maintain even pressure and flow. The Continental IO-360 has a mechanical fuel injection system that is very simple.
          The property belongs to a friend that has a nice farm that is 50/50 trees & fields. There is a nice wide creek that is like a small river that is in about a 1/3 of the farm on that runs parallel to the rear property. The neighbour farmer uses his fields and Jim cuts fire wood out of the forested section. Jim's farm is one that many of us covet as it is a beautiful pc of property. He lives about 3 miles from town on a quite section road. He has talked about selling it and moving into town but he appreciates what he has so much that he can't do it. He has a good sized shop and we assembled the airplane in a pole shed that keeps it out of the elements.

          Florida is nice this time of year. I spent a 2 weeks on Sanibel on the water facing the gulf coast and a couple weeks in the Orlando area. I really like the drive from Ft. Myers to Naples. I was lucky both times as it was very comfortable 80 all the time and sunny.

          The rubber press for flanges seems like a nice way to go. I came up with a system but the press is simple. I would like to know how fast Barrows is with his Bob stick as it may be faster to hand bomb them rather than all the time to create the tooling. There may be someone that pressed the flanges into the rubber may lend their dies.

          My partner is a veteran TIG welder that did piping and pressure vessel code repairs for about 30 years. We free handed making the fish mouth cuts in the tubes. There are apps to make paper patterns that can help to get the shape very close on the first run. We put a vertical in and tacked it then cut coped the next vertical. That lets a person move the vertical to work the diagonal. The second end takes a little longer to get it perfect. Once it is in then Tack and repeat. It is pretty simple and we just kept working the cut until the fit was perfect and the joint was a slide fit with no pressure. They fit was clean & close without forcing the tubes in. The slide fit leaves very little gap & if there is a lot of gap then the welds will pull. Once we had the fit Bob TIG tacked the tube in a few places so there was a lot of tacks in a cluster. We probably could have flown with the tacks. We put the fuselage in the rotisserie. We preheated the cluster, then Bob welded the cluster out in one go and then we post heated the joint then covered it with insulation. He jumped randomly around the fuselage until all the clusters were done. Putting all the tacks in I think was the key to it being straight. We made tee coupons and the welds hold while it takes a lot to break the tube off. The toughness of the tubing is impressive.

          A good resource is the EAA and they put on Sportair classes. The Lakeland Florida is full of home builders and the EAA may have some work shops in Florida.

          The other thing is registering your build and make sure that the inspections are done. We got into a hair pull with the Canadian MD-RA that do the inspections. I had an e-mail trail from the inspector that put the issue in their court so the MD-RA was at fault as I tried to comply at every step. They worked with us to get our inspections done. We have had great inspectors that really enjoy their work & are supportive of builders. Our last inspector said that his job is to get builders flying safely and help them through the process. The first inspector was very impressed with the wings and asked if he could refer other builders that may need some help. We were to do a presentation on building aluminum wings from scratch for the RAA which is a Cdn homebuilder association. It is good to develop a working relationship with your inspector.

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          • #20
            We were all set to but a farm in tennassee that was 120 acres. Stream- 40 acres flat hay fields..... balance in mountain timber. It was going to be heaven. But-- out buyer
            backed out and here we still sit. :-( It is all ready getting hot here. about 85 today. i get sick of the heat. Often 100 degrees and 100% humidity. Used to run 8 miles
            every other day at about 1pm in that. let me tell you -- that will get you in shape or kill you !

            The rubber pressing is easy for me as I all ready had the press from something long ago. the rubber too.
            I thought about making a small tool with 3 polyurethane rollers skate wheels arranged in a triangle like a cylinder hone. It would fit into drill press. It would rotate around
            and you would lower it into the sheet metal and it would "spin" the flange down into the wooden form as it rolled around it. Havnt tried it though. It might make some
            distortion since the perimeter would not held firm. It would be like a rotary power bob-stick.....

            I will probably go to the next EAA meeting coming up this month. I hope they are not all idots there !
            Some of the inspectors down here are just bureaucrats who reject anything that could threaten their status. Then there other who have seen lots of things and are actualy
            helpful and can send you in the right direction to make proper adjustments when needed. you can imagine which I hope to find ....... I do know one who is a retired chief
            FAA Maintenance compliance guy. His brother's family company builds the Pitts 12. But he is about 2 hours away now- maybe a little too far-- but we will see. I think he told
            me he is giving A+P tests and also IA tests these days now that he is retired. ( I giess that would be a designated examiner-)

            Looks like the nose ribs might be going to give the most "push-back" due to having the steepest curve on top and bottom. I think the others will be a bit easier.

            Looking forward to doing the tubing. Will be a while since I should probably get the wings mostly done first- so I dont juggle too many balls...... but I might order the
            tube kit before I need it. I plan on ordering the pre-bent spar cores..... as those seem to be the only bends that I might have trouble doing. I dont want ANY blemishes
            or inaccuracies there....... probably some places you might fudge a little - but that aint one of them. ! (IMHO ) But I have to get all the ribs done first.

            I didnt realize you were all the way up in the great frozen north..... no wonder its too cold to fly. Hope if you get some warm days comming up that they wont be Uber-Windy
            ones like we get here in march and april. That was when we had the tornado at sun-n-fun that wrecked lots of peoples planes. Strange- the Wx the day before was all most the
            same - just no twister--- but it looked like there should have been one.... black wall cloud across the whole horizon..... nasty.

            stay warm !
            Tim





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            • #21
              It sounds like that Tennessee farm would have been really nice. I have been in NC a few times and TX during the summer. I like Florida in the winter along the west coast at Fort Myers and south. I think the ocean helps regulate the temperature so it is very comfortable in Feb & March.

              The Asheville NC area was nice and may be similar to your Tennessee area. It was about 70 in on the coast in NC and it was so humid that we could barely take it. I was in TX at the end of summer and it was 95 so I cannot imagine what summer is like their. We have the greatest area in the summer with world class fishing. We are out numbered 5:1 by American anglers. A lot of pristine lakes every where and as locals we can take our camper trailers & boats out and can sit at any lake up to 3 weeks for free. Google Dryden ON and it will give an idea of how many lakes there are in NW Ontario.

              We made a couple extra MDF wing patterns that we cut the spar & false spar sections out to use to get the size and angles for the spars. An owner of a Heat & AC business allowed us to use his brake after hours. We were able to get our spars made so his help his help in getting it it done was appreciated. We had a roll of paper so we glued white paper on the spars so we could draw the fold lines. We had matching shorter pieces of aluminum for each part that had the same reference fold lines. We made a shoe for the brake to get the radius in the bends as described in the Beartracks. A couple trial bends showed us where to set the aluminum for the bend & the spars were formed to match the MDF templates. We bent 2 extras of each part and so when it came to assembling the spars we did a mix and match to get 2 pairs that matched together best. It is impossible to get them dead perfect but they were really close so mating matching ends is a reasonable compromise and it gave us good results. The paper on the spars was perfect for laying out all the caps, verticals & holes. The spar flange was exactly the same height as the rib flanges so we joggled them. It does not hurt to go slightly wider so the ribs fit between the spar flanges snug w/o a joggle. It is working with and adapting as you go.

              My brother made a pc of high efficiency equipment for sluicing gold. He said that he had the stainless steel sections cut in a shop that also folded the SS metal into chutes with a CNC brake. He had a number of pieces fabricated and he said the sections were all identical. I never heard of a CNC brake until then. You have a lot in your state and someone may be able to knock a set very quickly. There may be an EAA group in the area that you could join that has a shop.
              Last edited by Glenn Patterson; 02-13-2018, 04:54 PM.

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              • #22
                Originally posted by fairchild View Post
                ... I plan on ordering the pre-bent spar cores..... But I have to get all the ribs done first.
                If you're going to buy the prebent spars, I'd suggest getting them before you make the ribs so that you can make sure that the ribs you make will fit the spar. It'd be a shame to make a full set of ribs and realize that they don't quite match up with the spars.

                Comment


                • Glenn Patterson
                  Glenn Patterson commented
                  Editing a comment
                  Good point. We made our spars to fit the pattern that made the spar and rib flanges at the same width. We joggled the ribs and it worked out. If the spars are made by a third party then there is no way of knowing how the spars and ribs will come together.
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