Bearhawk Aircraft Bearhawk Tailwheels LLC Eric Newton's Builder Manuals Bearhawk Plans Bearhawk Store

Announcement

Collapse
No announcement yet.

Changes to Quick Build kits going forward

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Changes to Quick Build kits going forward

    We have tried to make the kits more complete and easier to build focusing on what builders seem to struggle with the most. At the factory last week we focused on one particular change to the kits. Drilling the ailerons & flaps completely so builders just insert the bolts, tighten the bolts/nuts, and all is done except covering. I discussed with Bob how we would implement this change, and think a description will be useful to everyone building their kits or scratch builders.

    At the end of this post I will ask for comments from you guys on a couple things.

    Bob had the workers make four plywood stands for the wing bottom and four more conforming to the wing airfoil shape on the top. See pictures - especially side view. Since we had just loaded the biggest truckload of kits ever (6 kits) in a 53 ft trailer four days before, we didn't have a fully riveted wing to work with. That's why all the clecos. We found that with these plywood boards top & bottom, it was super easy to position the ailerons and flaps vertically. First time we saw the aileron a little high, but adjusted the hinges to where the aileron fit tightly between the boards. Same with flap. Hinges were clamped in place with small C clamps.

    Bob instructed us to position the ailerons horizontally by first making sure the trailing edge rib that the wingtip is attached to was totally straight/inline with the outboard main rib. Then give the aileron the 1/2" spacing called for. Then space the flap with the 1/2" between the flap and the aileron. All pretty straight forward and easy.

    The only harder part was when the aileron nose rib was rubbing on the upper skin trailing edge when the aileron was moved. I was aware of this as on my new Patrol and my LSA also I had to remove some material from the upper skin trailing edge to give some clearance. Bob had us look at EVERYTHING to see why it was rubbing. That the aileron attach weldments had the proper distance from the rear spar - they did. The amount of skin extending aft of the rear spar in the pocket ribs area on the upper and lower skins. The upper was spot on. Lower was a little longer but caused no problem. The shape of the pocket ribs as made by the rib hydroform plant. They were perfect. So we couldn't really find any deviation from the plans of the parts being used to account for the interference.

    Scaling off the plans - the upper skin (where the rubbing was) - extends .500 aft from the upper bend in the pocket skin. Leaving .500 for that row of rivets for the trailing edge there in the aileron pocket area. After explaining to Bob what we saw - he said no issue trimming off up to maybe 1/4" of the skin in that area. Leaving 1/4" of area for that last row of rivets grabbing the top skin and the pocket skin. The goal was 1/8" gap between the aileron leading edge and the upper rear skin. Leaving room for the fabric covering that goes on the aileron.

    It turned out taking .150 gave a little more than 1/8" clearance required. Still leaving lot of spacing room for the line of rivets. We paid some attention to the vertical placement of the flap/aileron steel hinges so their attach holes had good edge margin on the .063 doublers on the aft side of the spars. The workers now understand how to do this and how the end result needs to be. I am sure the next time they do it will take a little time, but soon it will be quite fast for them to do this additional step on the kits.

    Per the plans - the hinges for the flap and aileron do not allow the pushrod rod end bearings Bob recommends to just fit in between the hinges as the ball of the rod end bearing is wider than the spherical bearings used on the attach weldments, So builders have needed to put a little joggle into the upper parts of the hinges where the pushrods attach. In the picture you can see a workers first attempt at joggling the hinges. Not perfect but certainly usable. The ones delivered with kits will look better.

    Now a question that I hope will give some of your thoughts on one change that Bob has considered. He has always recommend nutplates for the aft face of the aileron & flap spars so hinges can be removed. But recently he told me that he has never once needed to remove a hinge after covering. So he thought regular AN365 nuts were probably good enough. What do you guys think? Has anyone ever needed to remove aileron or flap hinges after covering? I have not. Please let me know your collective thinking on this question. While I do not have 3/16" nutplates down at the factory now - they could continue the same approach with nutplates if it is best. I can send some nutplates of that size down. Either way - the triangle and pyramid shaped reinforcing gussets will be all finish riveted. Not left to be finish riveted by the builder after installing nutplates. Please let me know what you think.

    One other question concerning all the changes in the kits during the past 1.5 years. I would like some opinions on how many hours of work these changes would save a builder. Here are the changes:
    1) Drilling wings to fuselage, and wing struts all drilled
    2) Fuel tanks finish installed in the wings with the straps made at the factory and the upper skin opened for the tank filler neck.
    3) Pouring most or all of the lead required for the elevator counter weights.
    4) Now having the ailerons & flaps finish drilled so just inserting the bolts places the control surfaces in the correct place.

    How many hours of work do yall think these changes saved? There have been some other improvements like the Patrol/LSA throttle set up. The new Model B ceiling that allows easier installation of skylights. Or continue to use a fabric ceiling. And the more finished way we are set up to install the fuel vales and gascolators. But these do not really save time actually building. But may save some head scratching time figuring out how to do these things. Your response on the time saved from us doing the above steps would be interesting.

    At this time of the year, we would like to thank you all for your business, your confidence in us, and your friendship. Mark

    You do not have permission to view this gallery.
    This gallery has 3 photos.

  • #2
    Nice work Mark. Always good to see these continual improvements.
    Nev Bailey
    Christchurch, NZ

    BearhawkBlog.com - Safety & Maintenance Notes
    YouTube - Build and flying channel
    Builders Log - We build planes

    Comment


    • #3
      On the nut plates. My plane may be the exception out there but in order to remove my hinge bolts I need to remove one side of my bracket to remove or install the hinge bolt.
      Drilling the wing and strut.
      I work by myself. I needed to build adjustable supports for each wing, set up a water leveling system, build a jig to drill the fuselage to wing attachments, set the dihedral, set the incidence, walk away and return to check all of the work, drill the struts. I don’t time my work so the best I can do is reflect. Best guess is 15-20 hrs over a week. Drilling the wings and struts in my view is probably the best improvement in the kit build process.
      These are all very welcome improvements in the kit. Now all I need to do is build another one. The new builders will probably not appreciate the improvements in the kit but the improvements should help other builders achieve a successful build.

      Comment


      • #4
        Mark, It's good to see the continued improvements you are making in the kits. In talking with many over the years about building a kit the one common aspect that gives some concern is that the Bearhawk kits are perhaps not as developed as some of the others with regard to how much is left to do. How much fabrication and detailed set up like these items are left to the builder. I try to assure them that all these things while somewhat time consuming are not complicated. They are however critical to the way the plane will fly so I'm glad that pre drilling the wings and struts and now the aileron / flap set up will be done, it should make a difference beyond just the time savings. Your level of wing close out compared to other kits is also a big positive. Building a set of wings from ribs and spars is a significant amount of work.
        As to your questions, my perspective is from a builder of an early kit so I can appreciate these changes
        I had to remove a bit of trailing edge skin in some areas to allow clearance for the aileron nose, probably 3/16" to clear the rivets and fabric. As long as edge distance is maintained I don't see a problem.
        I never had to remove the hinges and questioned why I would use the nut plates on the next build. I had assumed it was that for some reason the hinges would be installed after the skin was riveted down but they can easily be installed before with nuts instead. Like tailwind says a big issue is that the hinges are positioned so that the attach bolt can be installed / removed without hitting the side of the pocket. How many hours do these changes save?
        1/ A full day to set up the fuselage, water level, drill the attachments, hang the wings, set the dihedral, cut and drill the struts. Another day to check your work, remove the wings and get everything back to where you were. At least 15-20 hrs total.
        2/ Fuel tanks and straps, hole cut. - A lot more work here than it seems. 10-12 hrs
        3/ Pouring the lead for the tail - Beyond setting up the tail and getting the right weights calculated you have to get the lead, have a way to melt it and build a form for the lead section - 12 hrs. If you are going to do this at the factory just over weight it and the builder can drill out some lead as needed.
        4/ Setting up the flap/aileron hinges - 15 - 20 hours at least
        These numbers are my opinion for a first time builder, the second time is much faster. Good work on this!

        Comment


        • #5
          I agree with 942VT on the times.

          Great value added to the kits. I hope I get to do a full kit build some day. I'm trying to convince a local guy to let me build him a Patrol. He owns a Scout and a Husky and used to own a Cub. I just need to convince him that a Patrol is better than any of them.

          maybe worth noting: we installed our hinge brackets with nuts. We couldn't see a need to ever remove them. However, installing fabric around the installed hinge brackets was difficult and I'm not happy with the result. Nutplates would have allowed us to install the brackets after completing the fabric which would look much better and the cover job would likely last longer.
          Scratch Built 4-place Bearhawk. Continental IO-360, 88" C203 McCauley prop.

          Comment


          • #6
            Mark;
            You are definitely headed in the right direction. I think minimizing the number of things you need to do to the wings before you mount the wings at the airport a big help. Most of those are now done. 2 or 3 old guys lifting the wings on multiple times wouldn't be fun, but you might get lucky and sell a few more wings.

            I wouldn't have thought of this, but I just disassembled the fuselage stuff to paint the forward half of the tubing. Maybe offer, as a kit option, painting the tubing, or at least the cockpit tubing.
            I wasted a bunch of time on the fuselage doing and undoing things. The latest was painting.

            For a kitbuilder, it would be nice to put the wings on at the airport for the first time. With proper organization, take the fuselage, fit the gear, remove the gear, put it on a rotisserie if you want one, and it comes off the rotisserie covered, painted, interior mostly done, systems installed, boot cowl mostly or completely done.

            I am pretty sure I could do a second kit in less than half the time I did the first one, mostly do to installer error and disorganization.

            The extra wing stuff goes a long way to making the kit easier/faster

            Comment


            • Mark Goldberg
              Mark Goldberg commented
              Editing a comment
              John, most of us feel we could save a ton of time building the same plane a second time. I have always felt that one can be built in 60% of the time of the first one. But on the bright side - after building your 4 place Model B, a Patrol, LSA, or Companion would also fit in that time savings. We like "repeat offenders". Mark

            • svyolo
              svyolo commented
              Editing a comment
              I think #2 will be a mostly scratch built LSA. Tubing kit, spars and ribs, and maybe a few steel parts.

          • #7
            I don't think I've ever seen a kit company check in with the customer base first for suggestions on future kit changes. They always just make changes, and that's all she wrote, "deal with it!" An impressive difference, more companies should do it. Anyone know if Vans does this? I know RANS doesn't.

            Comment


            • Mark Goldberg
              Mark Goldberg commented
              Editing a comment
              About a year and a half ago, we did specifically what you say. Ask for suggestions. We got quite a few. Not all were adapted of course. But the idea is to make the kits as easy to build as possible. Mark

          • #8
            I think this would have saved dozens of hours, if not 30 hours of work. Allowing time for thinking and prep, then disassemble afterwards.

            Drilling the wings is at least 20 hours in my opinion, with all the prep work, planning, setup. If you get it wrong, then another 50 hours.

            I think the fuel tanks is another huge time saver, probably at least 15 hours again. There is so much stuffing around with lining the fuel tank hole up properly, perhaps even 20 hours.

            Altogether, that is almost 70 hours saved on the total build in my opinion. Then the profiled tail, and all manner of other changes to speed things up...

            I think you need to revise the 1,200 building hours on the website.

            That is a number the prospective buyers put a lot of weight on, and I think 1,000 hours is more realistic now. Talking in round numbers, for the basic build.

            If you are adding a skylight, then even more hours will be saved.
            Last edited by Battson; 12-16-2019, 03:33 PM.

            Comment


            • James
              James commented
              Editing a comment
              Hi Mark, I second a lot of the comments on here :-)

              I'm miles away from being ready to fly, but I reckon I've spent about 350hrs on my wings alone (mostly fixing things, or re-doing things).
              I'd love to meet some of these guys who can finish their wings in 100hrs, but then I'm not sure I'd like to fly in their plane! :-) :-)
              Rod and Jonathan have both reinforced my frustrations on mounting the aileron hinges, seems to take forever. I like the nutplates.
              I didn't like the poprivets that held the gussets and trailing edge on - I found them I found them difficult to drill out cleanly without damaging something.

              1) 1200hrs total build time seems really optimistic - if that's part of the marketing to sell kits, that's fine by me, but I personally can never hope to achieve that benchmark!
              2) Here in Australia, CASA mandates a 51% rule for building an aircraft - you only have to read the forum posts from the scratch builders to realise that we kit builders are YEARS ahead of them, even before we start. At what point do you feel that the helpful AVIPRO workers have built more of your plane than you have?
              3) My third point leads on from 2): don't do too much of the job for us, Mark. Building a plane should be a difficult, time-consuming project. That's part of the sense of achievement (and the learning that goes with it).
              4) The only change I'd make to the kits is drilling off the wing / struts. That step scares me, and it'd be so great to know I just slip in a bolt or two and it's all good.


              Already I find with the forum posts / literature, that the issues faced by builders of the older kits are being forgotten: as the kit's shortcomings are addressed, we still need to maintain documentation for all legacy kit builders out there. I'm getting my wingtips lengthened as we speak :-)

              Great product, great project - thanks so much Mark, Bob and the Avipro staff for getting us to a point already where the building is 90%+ enjoyable and satisfying.

              James

          • #9
            Not exactly sure why, but the most frustrating part of the project for me was installing flap and aileron hinges. I probably have 50 hours invested. I originally had some misconceptions of how to go about it that didn't help. Next most frustrating task was fitting the wing tanks, I don't even want to guess how long that took. I thought part of the issue was putting plans built tanks into a quick build wing. Mating wings and fuselage probably took another 30-40 hours and a couple helpers, but I really enjoyed the challenge of getting everything aligned perfectly, I can understand that a lot of people would just as soon skip that part. You are making a good kit into a great kit Mark, and of course the end product is terrific.

            Comment


            • Mark Goldberg
              Mark Goldberg commented
              Editing a comment
              Thanks Rod. We try to do our best. Mark

          • #10
            Mark, I think the kits are great and getting better. The improvements that you’ve made really limit the need to modify anything for the picky builder like myself. I just spent an inordinate amount of time making some mods one of which is now standard (skylight structure).
            Two items that I would square away that I’ve run into so far would be: 1) I found the kit awkward at the fabric and/or aluminum sheet area under the door. If one chooses fabric some creative modification is required to attach it underneath or if aluminum is preferred - tabs to attach it to the frame as Mr. Minelga did are required. If either option was ready to go (meaning built in) I would have happily stuck with that plan and saved time. If I had my pick, aluminum seems preferable and is how I’ve arranged my kit. 2) I decided that extra safety is worth the extra effort in my build and, with the help of a pro, fabricated four point harness mounts for all four seats. I think it would be worth it to most builders.
            Like the skylight I think the more you save guys like me from modification the better. Hopefully I’m done with all of mine. Cuz it sure is slow!!
            Almost flying!

            Comment


            • #11
              I will call you later to try and better understand what you are suggesting Ken. Yesterday I bought 240 ft of 6061T6 tube of 7/8" x .035. After it gets here next week - all kits (except LSA) will go out with the tubing cut to size for the aileron counter weights. A long piece and the shorter piece if needed. Just a little step to save builders from having to source the material. At the suggestion of a builder in Canada. Mark

              Comment


              • AKKen07
                AKKen07 commented
                Editing a comment
                sounds great! I’m a little jealous of the new kits already...
                This video shows the modifications that I made - including the tabs for sheet metal siding and seatbelt attachments. https://youtu.be/iewxCkSFr5s
                Last edited by AKKen07; 01-21-2020, 01:58 PM. Reason: More details...

              • Battson
                Battson commented
                Editing a comment
                This would be a good addition, I have run into some difficulty with that area from an ongoing maintenance perspective. A couple of small tabs to attach a piece of aluminium each side would be a great solution.
            Working...
            X