Billski's Fiberglass Bird

Discussion in 'Member Project Logs' started by wsimpso1, Sep 25, 2010.

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  1. Sep 25, 2010 #1

    wsimpso1

    wsimpso1

    wsimpso1

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    Working name is Aries. It is a two seat, side-by-side, low wing fiberglass machine intended to allow me and one other fortunate individual to travel and ski or dive.

    The space behind the seats to the horizontal tail is sized to fit a bag with four pair of cross country skis and poles, and the rest of the baggage space is sized for 200 pounds of bags like you would use for fly-in's, ski trips, and dive trips. Interior is 46" wide, and set up so that either my pilot wife (5'5") or my ski buddy/Best Man (6'6") will fit. So, it has a rather long tail arm, and empty the CG will be quite forward.

    The wing skins, fuselage skins, canopy and gullwing doors are vacuum bagged on molds while thinner things like the stabilizers and control surfaces are hotwired cores with the skins vacuum bagged on them.

    The wings are Riblett airfoils 37A315; thick and chosen for cruise CL of 0.3 and the tails are 12% thick. Flaps and ailerons are pivoted below the wing. On the flaps it gives a nicely formed slot for a significant landing speed reduction, while the ailerons obtain a bunch of aerodynamic balance that way.

    Pictures (which folks have been bugging me about for ages) will follow. Thanks for looking.

    Billski
     
    Last edited: Dec 25, 2010
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  2. Sep 25, 2010 #2

    wsimpso1

    wsimpso1

    wsimpso1

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    Let's put some pictures on here. I have only gone digital lately, so , we will pick up where the digital camera did.

    The fuselage tub, upper decks, wing skins, and spars have all been made, and we are getting into assembly.

    This is one of my vacuum gauges, bought at Grainger, with an attachment cup made from a PVC Pipe cap and attached with mastic. Simple, and it works.[​IMG]

    This is my canopy mold. The bird will have a fixed roof that will serve as a rollover structure with large gullwing doors and windows that wrap well up onto the roof. The first picture is after the first layup has curred and the PVC foam cores are bonded in by vacuum bagging.

    [​IMG]

    Next photo is the last layup of BID cloth tying everything together on the starboard door. From Right to Left is Imad, Lee, and Billski. You can see vacuum bag film (blue), batting (white), vacuum hose and epoxy trap. The mold was used to make both doors, and then the roof structure was built over the doors so that they will fit.

    Billski

    [​IMG]
     
    Last edited: Dec 25, 2010
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  3. Sep 25, 2010 #3

    wsimpso1

    wsimpso1

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    Now the fuselage is upside down and mounted on a strongback, and then the wing spars and upper wing skins are attached. You can see the wing strongback and the attempt at a wing jig supported by adjustable jacks. The particleboard jig moved too much for real accuracy, but I got everything aligned, spars attached to the fuselage, and upper wing skins attached to the spars. You can also see the foam plug for the centersection drag spar mold. It was subsequently modified to serve as a mold for making cap layups for the same spar.

    [​IMG]


    [​IMG]
     
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  4. Sep 25, 2010 #4

    wsimpso1

    wsimpso1

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    Lessee if we can put in a few more shots. This one shows the pass tube for the aileron control pushrod and the lower skin is there because I was checking fit of the various parts. You can also see the aileron linkage idler there in the stub wing, and the center section main and drag spars.

    [​IMG]

    This one was taken last week. You can see my torsion box with a wing jig built on it, and the starboard wing in it upside down. At this point, all of the spars and ribs have been tabbed in, the pass tube for the aileron pushrod is tabbed in, and I am getting set to do the flange transfer. The lower skin is hot glued to the rest of the wing jig, and resting on the floor. The thing that looks like a cherry picker made out of wood is just that, a light crane for setting the lower skin and its part of the jig into place and then taking it off again.



    [​IMG]

    Since then, I have piled dry micro on the edges of the spars and ribs and placed the skins to get the inside of the lower skin copied into micro. That gives the flanges someplace to attach in the following step.
     
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  5. Sep 26, 2010 #5

    wsimpso1

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    It seems that some folks can see the pictures, and others can not. I can get the pictures on my desktop, my laptop, my wife's laptop, my wife's work laptop.

    Jake! Help!

    I have opened my album with the same photos as a public album. Knock yourselves out! There is already a thread in the Hangar Flying area.

    Funny, no one has commented on my crowded shop, the stuff in the background, the parts, etc.

    Billski
     
    Last edited: Sep 27, 2010
  6. Mar 12, 2011 #6

    wsimpso1

    wsimpso1

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    I found an older photo: Bill with top and lower fuselage assembled.jpg

    This is the fuselage tub with the roof, gullwing doors, turtle deck, forward deck all fitted together with Clecos. My wife was disappointed that I was not bonding them together until I explained that there was a lot of stuff that had to be done inside, and putting the top half on was among the last things that would be done. Visible inside is the piece of plywood temporarily tying the roof to the sides.

    Since this shot, I have attached the center section main and drag spars and done a bunch of other work shown in more recent photos (which I will update soon).

    Billski
     
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  7. Jul 25, 2011 #7

    wsimpso1

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    More progress on the starboard wing.

    Pass tube for aileron control is glassed in, flanges have been transferred to the ribs and aux spars, ports have been added for a fuel finger screen, fuel level sensor (capacitive type), and quick drains. The anti-slosh doors, fuel return line, vent and balance lines, aileron bellcrank, flap and aileron mount nutplates, and NAV antenna are all in.

    I couldn't stand it any more, so I primed and coated the upper portions of the fuel tank bays, then prepped and bonded the lower skin. When I put the wing into the jig, it was still kind of flexible, but now it just rings when you tap on it anywhere. My wife and two of our friends helped out with the bond job, and we used Gougeon's structural adhesive. Nice stuff. Since then, I have gone around and sealed the forward and aft spars to the lower skin, put on all of the closeout tapes on the end ribs and the trailing edge spar, and am departing for OSH in 10 minutes (IFR reservation opened up so we can fly high over Lake Michigan!).

    Pictures when I get back, and can afford the time to mess with the recalcitrant loader.

    Billski

    Here's to clear skies and cloudy beer.
     
  8. Mar 25, 2012 #8

    wsimpso1

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    It is high time I added some more photos. Here is the starboard wing with flanges transferred, anchor nuts for aileron and flaps mounted, slosh doors attached, fittings for fuel pickup and return are in, and even have fittings for the capacitive fuel gauges in. Then I primed it with Dow-Corning pink silicone prime and followed with Dow-Corning White Fluro-Silicone sealer. yeah, it is just about ready for closure in this picture.

    IMG_0907.jpg

    If anyone has specific details of any of this stuff, just ask and I will post photos I have of the item.

    Since this photo, I have bonded the lower skin to the wing using Gougeon Proset adhesive (great stuff) using the wing jig pictured. Scary job, because you can not fix it is cured and is wrong. I have ways of looking at each of the joints between dry and wet areas of the wing, and they looked good on the first try, so we let it run. Before bonding, a thump on the wing would go "boom". After bonding it goes "bingggggg". It sure sounds and feels solid.

    After that, I sloshed the whole tank first with primer, then sealer. The primer is water thin, and my lower skin wing weeped. After a couple tries, the porosity was filled, then sloshed it with fluro-silicone. It is sitting in the roll-around wing rack now. The material scientist in the house has doubts about being able to make paint stick to that pink silicone. We shall run some tests and figure out something.

    For the port wing, I am brushing the wet wing surfaces with thinned epoxy to fill the porosity before assembly and hitting the wet areas with sealer-primer...

    IMG_1129.jpg

    I knocked down the wing jig and put it back together for the port wing. I have the upper skin/spar, ribs, leading and trailing spars, and all in it, and am about to transfer flanges.

    IMG_1125.jpg

    I also put my strong back on casters and flipped the fuselage tub upright so I can start populating it with parts. So far, I have temporarily mounted the roof, bonded in the seatback bulkhead, made baggage bay tunnel walls, worked out details of the control system, and built my little dive brake. None of it is mounted yet, as I will make all of the pieces and make sure that they all work and assemble first. Lots of steel tube and flat stock to cut, jig and weld for stuff like the sticks, walking beam, flap handle, bellcranks, etc. This stuff all has to be assembled inside the airplane and be removable later, so I am doing a lot of noodling.

    IMG_1131.jpg

    Here is a shot of your intrepid builder's other half sitting in the cockpit. Yes, she is a pilot and yes she intends to get left seat time in it. It looks like an airplane with the roof on the tub. She is imagining flight in it and is very encouraging of me going out and working on it.

    IMG_1134.jpg

    Ah well, that is all of the news that fits for now.
     

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  9. Feb 17, 2013 #9

    wsimpso1

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    New stuff. Building the flaps using hotwired foam cores, Triax cloth, and vacuum bagging. Oh, and two WMU aero students are no longer novices to the process.

    IMG_1364.jpg

    That is the cores supported in the cutoffs, ready for laminating, with the mastic on the table for the bag. We got kind of busy and did not take pictures until we got nearly done. We installed TRIAX cloth with judicious amounts of epoxy, then peel ply, then perforated ply, then batting, then the blue bag film. You can see the vacuum fitting (1/2" PVC pipe fittings) on the right.
    IMG_1368.jpg

    Then we turned on the vacuum and it ended up looking like this.
    IMG_1370.jpg

    Yeah, that picture was taken this morning, but that's what it looked like all night.

    IMG_1374.jpg
    Now this is with the bag and mastic removed, but the batting still on it.
    IMG_1375.jpg
    With the batting and perforated ply removed.
    IMG_1377.jpg
    And with the bottom cutoffs in place so I can trim the bump at the thin end, populate the core with pieces of high density foam for mounting the hinges, and make ready for glassing the top side. More on that later.

    Billski
     
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  10. Apr 13, 2013 #10

    wsimpso1

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    OK, now we get to installing the hardpoints, glassing the other side, and putting closeout ribs on the ends of these flaps.

    IMG_1374.jpg

    First we have to peel the bag film and batting from the flaps.

    IMG_1375.jpg

    This exposes the newly applied fiberglass and epoxy.

    IMG_1377.jpg

    And the raw foam on the top side of the flaps. Hmm, I did not take any pictures of the high density foam for embedding the hinge pieces nor did I photograph the phenolic plate for attaching the actuating pushrods. I also did not get photos of trimming the foam bumps on the trailing edge and exposing the bottom glass for closure with the top glass. We glassed the tops by wetting out the glass on visqueen and then transferring it to the foam part. Quick and fun, and it took all six sets of hands to move a seven foot long strip of wet glass into place. It worked slick and did a nice job... I did get photos of the excellent folks who assisted in getting the top covered in glass, peel ply, perforated ply, blanket, and bag film. Thanks go to Adam, Beth, Nancy, Jacob, and Anne for their good cheer and very able assistance.

    IMG_1381.jpg

    You can see the hard foam and phenolic through the glass...

    IMG_1392.jpg

    Here is a shot of the flaps as they were after peeling...

    IMG_1388.jpg

    Now some of you may notice that the flaps do not look like they are perfectly straight, but in fact very slightly twisted. Well, they are not screwed up, the wing has 0.75 degrees of twist from BL24 to BL168, and the flaps include that tiny bit of twist.

    IMG_1399.jpg

    And this is a shot of the phenolic plate exposed, and a closeout rib installed. Several things are shown here. First, the closeout rib attaches the skins from top and bottom together, which will prevent warping and delamination of glass from foam cores. Second, the closeout ribs on the inner ends also serve to bond the phenolic plates to the fiberglass over a much larger area than just to the top and bottom skins. Third, the six bright dots visible are countersunk rivets attaching three anchor nuts to the phenolic plate. The holes in the phenolic and threaded holes in the anchor nuts are temporarily filled with green modeling clay to keep epoxy out of them. Next step is to remove just enough fiberglass to remove most of the clay and then attach a laminated aluminum bracket with three AN-3 bolts for the pushrod that actuates the flaps. Stay tuned...
     
    Last edited: Apr 13, 2013
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  11. May 11, 2013 #11

    wsimpso1

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    Since I updated this with flaps, I have designed, made parts, and tack welded the flap actuation system. Next step on that is off to a friend's house where he will TIG weld them and then bore them for airframe bearings. When that is done, I will bond and glass in the mounts for this system - it attaches to the aft side of the drag spar. Then I can bond and tape the baggage bay tunnel sides. Big excitement in that. Ailerons follow too. And, I have figured out how to do time lapse photography with my camera, so I am planning to document fairing the flaps and building the ailerons that way.
     
  12. Oct 25, 2015 #12

    wsimpso1

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    Wow, it has been a long time since I updated any of this.

    Primarily been working on design and build of control systems.

    The sticks fit in forks on a walking beam, have a tie rod between them underneath the walking beam, and actuate pushrods that run out the wing. All of this is between the main spar and the aft spar in the cabin. The walking beam will also drive a big pushrod that runs aft to the elevators. These pushrods are not built yet. You can also see the flap Johnson Bar in flaps 50 position.

    IMG_1999.jpg

    Flaps have a Johnson Bar between the seats, with a pushbutton on the end and four positions to lock the thing (0, 15, 30, and 50 degrees). The Johnson bar mounts to the aft spar and actuates two pushrods, one for the torque tube on each side. The torque tubes are behind the aft spar, and will actuate the flaps through short pushrods yet to be built. The torque tube outer bellcranks bottom on the phenolic/fiberglass mounts when at zero flaps. Several things dictate the split torque tube, one being practical build/install/service, and another being the size of the aft spar deflections under some conditions. The pushbutton actuates the lock plunger with two little pushrods and a nylon slider in the bend. A return spring is mounted at the bottom of the Johnson Bar. Bearings on the stick, walking beam, torque tubes are ball bearing airframe bearings, and the pushrods are spherical joints. Works slick. Photo shows the middle of the aft spar, end of the Johnson Bar on the right and the torque tubes on the left, and the push rods in between.
    IMG_2000.jpg
    This is the torque tubes at the center with pushrods from the Johnson Bar.
    IMG_2007.jpg
    This is the right side torque tube:
    IMG_2006.jpg

    And this is the right end of the right tube, with the bellcrank that will drive the flaps with a short pushrod not shown. Left side is similar.
    IMG_2008.jpg

    Then there are the rudder pedals. Adjustable fore and aft, bottom hinged, and toe brakes. They have an S-Tube to shorten or lengthen rudder cables that are anchored on the firewall. They adjust by spinning a little wheel with a knob on it that turns a lead screw, sliding the assembly away from or towards the pilot. Each pair adjusts independently. There are four sets of parts, and I am showing only one. Left photo shows one main arm, the pedal, the brake lever, and the S-Tube/brake axle. The main arm slides axially on the big tube near the top, while the pedal pivots on the little axle near the bottom, The rest of the left photo and all of the right photo shows the rudder pedal in the center, the brake pedal upper right, and the S-Tube/brake axle lower left. These parts are all powder coated, have grease fittings, and hollow set screw locking pins.

    IMG_2003.jpg IMG_2004.jpg

    Then there are the bellcranks in the wings for taking the long pushrod pulls from the sticks to the ailerons. I had built the bellcranks and brackets from aluminum with two airframe bearings pressed in, then I figured out that I really did need control stops out near the ailerons. Since they needed to be welded, that means steel in my shop, so I made a new bracket for each side that includes a tab to screw in and tighten the stops. Not painted, but it fits great. The photo is taken through the inspection port in the bottom of the wing, looking into the equipment bay at about BL 124. You can see the bellcrank, both brackets, the long pushrod and its rod end, and the cable for the VOR antenna in the bottom skin.

    IMG_2002.jpg

    Next step is we picked up the landing gear leg blanks from AED in Indianapolis. Good guys. They acquired 4340 steel plate, 5/8" thick, annealed, and had a shop put the bends in for the mounting end and the axle end to my specs. Parts lay out perfect. We have to cut out the parts, dress all of the edges and surfaces, drill for the anchor ends and the axles, then send it out for heat treat and shot peen. Then come the brackets and laid up pads to hang them between the spars. More fun to come.

    So, that is all the news for now.

    Billski
     

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    Last edited: Oct 25, 2015
  13. Oct 26, 2015 #13

    wsimpso1

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    Wow. 16 Likes. I guess that I should post more photos.

    Some other comments. Yeah, in final assembly, there will be large diameter washers over the rod ends and airframe bearings to ensure that we do not get full disconnection if a bearing fails, and the joints will all be closed with AN hardware either self locking nuts or castellated nuts with cotter pins. This is all just functional checks...

    The transparent tube with the white ends is the form for making one (of two) elevator pushrods, and is being used to check that I indeed had room for it around the flap mechanism.

    Also, some may have noticed that there are no travel stops on the stick for pitch movement. I have not added them yet, but I will. Aileron travel stops are on the walking beam.
     
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  14. Nov 14, 2015 #14

    wsimpso1

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    New photos of Landing gear legs in process.
    IMG_20151015_154644762.jpg 2015-11-13 09.50.35.jpg 2015-11-13 09.50.45.jpg

    These photos show:

    A landing gear blank held by the author, made of 4340 steel, 5/8" thick and 5" wide, bent per my specification. about 50 pounds each. We had just picked them up from AED in Indianapois, and were about to put them in the Trusty Archer for the trip back to Ann Arbor.

    Two looks at one blank with the saw template but not sawed out, and one after sawing. A friend has a big bandsaw with bimetal blades and can be adjusted to the right speed. About 240 inches of sawing at about 1"/minute. Much lighter and much springier.

    Next step is angle grinder and belt sander work to make them perfect, then heat treat and shot peening.
     
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  15. Nov 15, 2015 #15

    wsimpso1

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    10 new likes for a couple pictures of big steel parts. Thanks guys. I will wait until the gear is more complete for the next photos.

    Bill
     
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  16. Nov 2, 2016 #16

    wsimpso1

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    Way overdue to show some progress. In my own defense, Beth and I did caretake a house in Florida for two months, spent a whole month on grand tour of the west in a little airplane, spent 10 days at Oshkosh, and participated in Beth buying an airplane and making it suitable for more adventures. Now for some progress. The main landing gear legs, their mounting saddles, laminations to attach the saddles to the main and drag spars, are complete, painted, and fit in the airplane. On top of that, the control sticks, walking beam, center and intermediate aileron pushrods, aileron idlers, and elevator pushrods and idler are all complete and fit in the airplane. And they all run without binding or contact with anythin.
    IMG_20161030_225805.jpg

    OK, this and the next one are from the left side looking down and right towards the main and drag spars in the cockpit area. You can see the seatback bulkhead to the right and the right side fuselage wall farthest away from the camera. Front of the airplane is to the left in the picture. Control sticks are 4130 built up from curved tubing, straight tubing, and flat stock. Oh, and all of these parts are welded\, or sometimes brazed with O-A torches. There is a fork for a pushrod that connect the two sticks that is up high to clear the landing gear saddles, and another fork to pick up the intermediate pushrods that extend out through the cockpit wall to an idler on each side about BL48.

    The sticks are mounted to a walking beam, also built up from 4130 tube and flat stock. The sticks pivot for aileron actuation in forks on the walking beam and drives the link pushrod and intermediate pushrods. All of these parts are a very light gray.

    The walking beam pivots on phenolic/glass mounts laminated to the main spar and drives the elevator pushrod aft, through the seatback bulkhead, through the aft baggage bay bulkhead to an idler. The idler has positions on it for a bob wieght and for a down spring, if such things become necessary. A second pushrod extends aft to the elevator bellcrank. The elevator is not yet mounted. The walking beam has adjustable travel stops for aileron and elevator travel.

    Also in the picture is the flap handle, which drives two small pushrods to the walking beams to take flap actuation outboard. These parts are dark grey. The first photo shows the flap mechanism in Flaps 0 setting, the second in Flaps 50.

    IMG_20161030_225900.jpg

    You can also see the landing gear legs, bright yellow. 4340, bent to shape, cut to width, mill and bend marks polished out, edges radiused, holes drilled on a mill, heat treated to 260 kpsi yield strength and shot peened, then primed and painted. Yeah, there will be fairings on the gear legs, but some small parts of the legs may be visible, so I painted the legs the same bright yellow I have selected for finish color. Each gear leg fits in an outer saddle near the fuselage wall and is connected to the spars and fuselage wall by a beefy fiberglass lamination. The outer saddle carries landing loads and torsion from wheel spin up and braking. There is also an inner saddle for each leg that reacts off the rest the landing and braking loads. The saddles are light gray.

    The gear is held in against side loads by a 3/8" bolt through the inner saddle and hole in the end of the gear leg. The inner saddle also has urethane rubber cushions for landing loads and nylon pads to restrain the end of the leg against braking loads. The gear is held against loads for landing, braking, and wheel spin up by nylon pads in the outer saddles. I fitted each piece to be a firm interference fit, with torquing the bolts on the closure plates firmly clamping each piece in the saddle. I hope that in use they will remain free from slop, but we shall see.

    IMG_20161030_225817.jpg

    These photos show the main landing gear legs, main and drag spars and the outside of the fuselage. No axles, wheels, tires, or brakes yet, just a chunk of hardwood plywood to keep the end of the gear from rubbing on the ground. You can also see an intermediate aileron pushrod and the aileron idler. May not look like much, but it is pretty exciting to me.

    IMG_20160723_060453.jpg

    Well, that is it for now. Gotta clean the shop and get on with populating the tub with stiffeners, seats, instrument panel, rudder pedal system, etc.

    Billski
     
    Last edited: Nov 2, 2016
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  17. Dec 7, 2016 #17

    wsimpso1

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    Some details on the main landing gear. I should have put this on months ago...

    I designed it doing analysis in Excel and math straight out of Pazmany's book on landing gear. Being as the max gross is planned at 2150 pounds, and I am far from a perfect pilot, I used FAR Part 23 to guide me in selecting the sink rate at contact and choose 3 g for landing gear reaction. I computed loads due to kinetic and potential energy at contact, tire spin up loads, including lateral loading. Other cases included max braking, max side load, and others.

    The gear is anchored in a main saddle at the fuselage wall and an inner saddle closer to fuselage centerline. The gear legs are max width at the main saddle, and the width tapers towards both the inner saddle and towards the tire tread contact patch.

    I modeled the gear leg at 10 increments between the main and inner saddles and 15 increments between the axle and main saddle, computing shear, bending moment, torsional moment, and total stress state at the corners of the rectangular cross section in each of the 25 sections. Load and deflection were fed back and the calculation allowed to iterate so as to give stresses and energy absorption with the gear leg deflected. Taper was adjusted to make the leg as close to a constant stress spring as possible, while flaring for the axles and inner saddle bolt holes.

    Material selected was 4340 steel, heat treated to a yield strength of 260 kpsi. Plan is to use 500x5 wheels, 6 ply rated tires, Grove magnesium wheels, brakes, and axles. Tire deformation at 45 psi was included in the math.

    I also ran designs in 7075-T6 (Robbie Grove does his legs this way, and offers gun-drilling for the brake lines too), but aluminum legs plus saddles would not package in between my spars, so that was a non-starter. Weighed more than my steel setup by the time it was strong enough and had enough travel too. I also started down the path of checking out Harmon Lange rod gear. I was not happy with how I would have had to attach the gear to the airplane - packaging issues again. So, flat steel springs it is.

    I iterated the gear leg length, thickness, width at the main saddle, and angle from vertical to minimize total gear weight (gear leg + saddles + mount laminations). While a lighter gear leg could have been designed, it would have resulted in a heavier total system. I settled on a system with 5/8” thick and 4-5/16” wide at the main saddle. Weight for the leg is 23 pounds.

    Then I had to build the thing. Bigger problem than you might think. At OSH 2015 I found AED Motorsports (www.aedmotorsports.com) in Indianapolis IN who bid on buying the steel and having it bent. Here is a hint for those of you doing this sort of thing – make sure that they know you are not in a hurry, as they can save you money if you can wait a month or two to get your stuff. They got me the steel, did a great job of having it bent to my drawing, and did it for a good price. Nice folks and good parts. Gotta love that. To pick it up, we ran down to Mount Comfort (Indy) in the Trusty Archer, visited with Judy and Boyd Birchler and EAA1121. Some of the nicest folks I know.

    Back home, I made templates of the tapered gear leg, glued them to the bent legs, then begged the use of big metal cutting bandsaw from a friend. Let me tell you, it takes hours supporting those 50 pound pieces of steel while you push it through the bandsaw. Then out comes the angle grinder with 40 grit then 80 grit flap wheels smoothing the surfaces, radiusing the corners, removing the bend marks and mill marks, etc. Buy the wheels intended for stainless or high strength steels. Lotta time in this too.

    Then off to another friend’s house to use his milling machine to drill for the inner saddle bolt holes and holes for Grove axles.

    In the meanwhile, I searched for a heat treater. In metro Detroit, you might think that would be no big deal. Well, parts this big can not be done just anywhere, but I got guys with salt bath for soak and oil bath for quench and who wanted the job. Wyatt Services (www.wyattservices.net) in Sterling Heights MI got the nod. Good folks and good service. I fabricated a heat treat fixture out of ¼” mild steel plates, 1” square tubing carefully cut into 24 pieces all the same length, 1/4" all-thread, washers, and nuts (all un-plated to prevent poisoning the salt bath). The plate held the bent shape of the gear, large diameter holes cut to allow circulation of heat bath salt, quench bath, and tempering. The square tubing held the plates a consistent distance apart and supported both sides of the leg (kept the leg from twisting) at the saddles and at the axles, the all-thread, nuts and washers held the whole thing together. I included a chunk of round tube as a hoist point that let it hang with the narrowest width for going in and out of the various furnaces. The fixture worked great, and I had parts with big strength and lots of toughness.

    Next was shot peening. This is to make sure that the now very high strength steel does not want to grow cracks over time. Is it absolutely necessary, given that only a tiny fraction of the landings will ever be even half of the design loads and the number of load cycles will probably number only in the hundreds or maybe thousands? Maybe not, but Cessna and Pazmany and Harmon Lange all advocate for it, so I did it too. It took some effort but I found three suppliers, and I took the legs to Metallizers of Mid-America (www.metallizeronline.com) in Belleville MI and they shot peened it with hardened shot to my spec.

    After that was paint and painstakingly fitting the saddles to just barely be able to go together and clamp in place. Making the saddles turned a lot of aluminum into chips at a friend’s house.

    So, that is the tale of the landing gear. Would I do it differently if I had to do it again? Maybe. The only shop to bid on my gear in steel, complete, heat treated, shot peened, and epoxy primed wanted $10,600 for two gear legs. UGH. I know of a shop that exclusively bends structural steel (for buildings and such) that I might have gone with for bending, but AED’s fabricator did a nice job, and my parts were right on to my drawn shape, so that is tough to argue with.

    I give a hearty recommendation for AED, Wyatt, and Metallizers for those of you close enough to use them. AED is definitely the go to guy for the metal, and also carries aircraft tubing and streamline tubing that is actually straight - no long curves...

    Billski
     
    Last edited: Dec 8, 2016
  18. Jan 23, 2017 #18

    wsimpso1

    wsimpso1

    wsimpso1

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    OK, the metal working is done for a while, I cleaned, sorted, pitched stuff, and finally got back to basics. Fiberglass part fabrication. Have hardly done any in over a year...

    I decided that I need the seat pans and centerline tunnels before any other parts. My seat pans will sit on top and sort of in between the main and drag spars. Anyone who has seen the photos above can tell that the volume between the spars is not exactly clear of stuff. The sticks and walking beam is in the way, so are the outer landing gear saddle supports, with bolt heads sticking up. So, the underside has to be profiled to give room for that hardware, and the whole thing has to be strong. How strong? Well, they have to be adequate to carry a one time crash load of 19 g and duty at 6 g with an FOS of 2.0. In addition to that, the world has found that the best way to make a ConforFoam cushion suck up the crash pulse is with a really stiff, strong seat - no rebound. So, how to accomplish this?

    Well, the folks at Oregon Aero (who are the folks who figured out that these memory foam cushion perform best with stiff, strong bases) are selling a very sturdy frame. I talked with them and came to the conclusion that I can get a really stiff seat form at very low weight and bulk by cutting up a bunch of foam boards, lay them flat and glass the large flat and edges, bond them together into recognizable seat pan, and glass that. The glass on the flat side of each board serves as a shear web and laps on the top and bottom surfaces. The glass wrapping the whole thing serves as a spar cap. Pick glass and orientation based upon loads. Then I fooled with the math for a few minutes, analyzed my shape, and then iterated the amount of glass on the individual pieces and around the while thing. Check of the weight and it looks OK. Oh, how am I going to hold it in place? Velcro! Don't laugh, bumpers are being held on cars with Velcro.

    Looked over the space, came up with a basic template for my flat parts. The template plane is vertical and parallel to the long axis of the fuselage. I worked out the relief of the underside at pertinent BL stations. I have several boards of 1" extruded polystyrene foam, so that is most of my parts. I also needed one layer of 1/2" and three of 1-1/2". Cut out and labeled some templates, made a cute little hotwire saw (I had a 40" and a 52", now I have a 12"), and with some assistance from a buddy, we ganged up a bunch of foam and cut the pieces out. Went back later and modified some of the pieces that fit one template one surface and a different template on the other surface... If all of this is tough to follow, just look at the pictures. I set them up and started smoothing the inevitable little steps and jogs. Next step is to cut out the space fopr the stick, then figure out which side gets glass forming a channel web, then lay them all out on the table, wet, apply, vacuum bag. Maybe tomorrow. In the mean time, let's look at photos.

    IMG_20170123_151844[1].jpg Ok, here you can see the basic seat shape. It is about 18" on a side. The three purple pieces in the middle were left big so I could get the underside correct before cutting out the clearance for the stick, then the seat profile will be finished.
    IMG_20170123_151217[1].jpg This shows the underside of the entire stack of the right side seat, with the profiling done. Gotta open the middle for the control stick yet.

    IMG_20170123_151302[1].jpg IMG_20170123_151318[1].jpg These show the underside of the left seat with only the pieces that transition from one shape to another. Remaining foam carving step here is also to cut the opening for the stick.

    Ah well, time to check my math for needed glass and then go back out to the shop.
     
    Last edited: Jan 24, 2017
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  19. Nov 4, 2017 #19

    wsimpso1

    wsimpso1

    wsimpso1

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    It has been awhile!

    Last post I was playing with the seat pans. Well, I glassed 'em and assembled 'em, and then found that I would have to make big mods to clear the rudder cables and seatbelts and even the sticks. More likely to make new ones out of 1-1/2" foam, temporarily assemble them, make all of the clearances work, then glass them up and make 'em for real. Not yet though.

    So, I built the pieces for my console and put it together. The Elevator push-pull tube goes through the middle, the flap handle works with it, and there is a small storage compartment under the elbow rest. I vacuum bagged each side on a table, then jigged parts to hold the halves together, and made covers for each of section. Light and nice, will get bonded in later.

    The photos also show the sticks in place with the seat pans and the console. Sitting in it, everything seems to fit nice, and my pilot friends have been in it and making airplane noises!

    172.jpg 176.jpg 180.jpg 185.jpg 199.jpg

    Next is the rudder system.

    Billski
     
    Last edited: Nov 4, 2017
  20. Nov 4, 2017 #20

    wsimpso1

    wsimpso1

    wsimpso1

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    Rudder system is way more fuss, as I have adjustable rudder pedals then have to get everything aft while leaving a lot of baggage capacity.

    The rudder cables are anchored to the firewall, go through S-tubes on the pedals, then run aft through fairleads in the seat back bulkhead. The two outer ones go through a couple turning blocks and converge on a big bellcrank at centerline just behind the seatback bulkhead. The two inner cables go through fairleads and connect to the bellcrank too. Fairleads were made of Delrin, turned on a lathe and the nice blend radii (5" radius) were cut using a piece of 4130 shaped with an angle grinder, then held in the lathe.

    665.jpg 695.jpg

    Those outer two cables go through turning pulleys. I used standard airframe pulleys and mounted them with brackets made of vacuum bagged fiberglass, glued in steel bushings, and bonded the brackets to the fuselage walls just behind the seatback. The wooden thing is a fixture to hold them in place while being bonded. The pulleys themselves and the inner brackets are not in the photos. If you look closely just above the flap torque tubes, you can see the rudder cable fairleads in place.

    1064.jpg 1065.jpg

    The fairleads then go through drilled holes in the seatback bulkhead and are retained with a twist of safety wire. Next is the bellcrank. If it looks kind of beefy, lets remember that it has travel about 4" and each cable can have 400 pounds on it. Yeah, I know, FAR Part 23 says less, but I have demonstrated way over 300 pounds with each foot... So it is kind of beefy. Several pieces of flat steel, folded flanges, tube, welded/brazed, airframe bearings.

    671.jpg

    The bellcrank is supported by a little hollow truncated pyramid of fiberglass on the bottom, and V of fiberglass attached to the seatback bulkhead. The only photo of the pyramid is under vacuum. The V is 12" wide and 16" long, but has since been shortened and flanges attached to the open end of the V. Steel bushings to allow service work, and wrench access for the same.

    664.jpg 1063.jpg

    The cables that go aft from the bellcrank are fiberglass rods with fabricated steel ends and rod bearings that go to a little idler fabbed up out of sheet metal, tube, welding and some airframe bearings. The idler is supported about 40 inches forward of the rudder hinge line by a bolt mounted in a couple steel bushings, one in the belly and one in a fiberglass bracket. Sorry, pictures later maybe. Then a Kevlar push-pull tube back to the rudder. All of this fuss is to get the travel and forces about right, to keep the parts in the tunnel so the baggage bay is big and functional, to avoid messing up the various antenna buried in the fuselage, and deal with the fuselage's pressure recovery shape. The Kevlar push-pull tube was laminated over a 1-1/4" fluorescent tube and debulked with electrician's tape. The second photo showed the end fittings while I was checking that the fir was correct before turning the tapered ends and threading...

    655.jpg 656.jpg

    So that is what I have for the rudder system.

    Billski
     

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