Billski's Fiberglass Bird

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

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  1. Nov 5, 2017 #21

    wsimpso1

    wsimpso1

    wsimpso1

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    OK, got a picture of the rudder bellcrank and supports all together, they are not yet bonded into the airplane. The little truncated pyramid will be mounted to the floor, and the V will get those flat faces bonded to the back of the seatback bulkhead. All parts were previously pictured, but this shows us how they work together.

    IMG_20171105_181731[1].jpg

    More soon.

    Billski
     
    Last edited: Nov 5, 2017
  2. Feb 21, 2018 #22

    wsimpso1

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    Trying Again... Fuselage is upside down, installed wings, fine tuned the connections, got the drag spar fittings aligned and connected, made new bottom stub wing skins with a trough to get the main gear in and out, installed all of that. Let's look at the process:

    First off a couple pictures of the new lower stub wing skins. I made the two access panels and a panel to close the troughs, trimmed to size and taped them into the molds. Then I made the wing skins right over them so I know the fit is just about as good as it can get. The wing skins are made in hotwired molds and vacuum bagged. Skins are one ply each of 22 oz Triax and 18 oz BIAX, with 3/8" PVC foam cores and some extra tapes on edges and around ports. Access panels are similar. And the lovely wife. Hi Beth!
    IMG_20171213_140510.jpg IMG_20171213_140538.jpg

    Then I made a form for each trough over the wing skin, and did the layup of the troughs, to be trimmed and bonded on later. Material is 18 oz BIAX on both sides of 1/4" PVC foam cores.
    IMG_20171227_144515.jpg IMG_20171227_144526.jpg

    Here is what it looks like with the wings on and a stub wing being fitted.
    IMG_20180120_212058.jpg

    Below is a picture of the fitting attaching the outer panel drag spar (right side) to the center section drag spar, and an example of my seat belt harness mounts. I just can not get rid of them... So, the AN4 bolts are permanently attached to the center section with nutplates on the other side, the AN6's come out to fuss with build and transport to the airport. The seat belt mounts are all pretty much the same. Four AN3 bolts, four bushings to spread the load, 1/4" phenolic plate, 6 BID on each side. Built-up brackets inside for connecting to cables, and sandwich plates on the outside. The phenolic and bushings are "below grade" and the bolts will be permanently bonded in and faired over - they are on the outside.

    Billski
     

    Attached Files:

    Last edited: Feb 22, 2018
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  3. Feb 22, 2018 #23

    wsimpso1

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    I checked alignment of the wing outer panels to each other by making templates that hooked over the leading edges and fit on the bottom surfaces for each of BL 25 (next to the fuselage), 50 (join between inner and outer panels), and 168 (tip). Once on, I sighted along the straight "bottom" edges and confirmed alignment. Ended up making upper templates too, and found that the outer panels are about 1/8" thicker than they should be at BL50, but shape is good and tips are within 1/16" and very good at BL168. That is about 15.3% and 15.2% thick, I expected it, and I can live with that.

    Outer panels were really good to each other - they should be the way they were built. At BL25, something was not right. I had to insert spacers at the main spar to get AOI right. Well, I did set up the main spars a little small through there, but this was larger than expected... Eventually I traced it down to the center section drag spar being about a 1/16" aft of where it is supposed to be and a tiny bit vertically out too. Sloppy jigging Mr. Bill! That all makes the thickest part of the foil quite a bit thicker when things are aligned correctly. By the time I got done shimming to fit the root section around spars and get the AOI right, I had a 15.8% thick foil.

    Sigh. Interpolated between 15% and 18% for 15.8%, replotted the template profile, adjusted the templates, checked top and bottom, it all fits, reset the shims to position the skins correctly, and bonded the skins in. Once the bonding along the spars was made, I glued in some foam strips at the blend between wing and fuselage. With all that cured, I faired the foam, and bonded the skins to the fuselage across the foam. It is starting to looks like an airplane instead of a boat with outrigger spars.

    Next steps are ailerons, hinges for the flaps and ailerons, trimming the wing skins to fit with flaps and ailerons, and the wiring runs from fuselage out to wing tips. Once they are all in, then I get to fair the bottom of the wing and fuselage before bringing the fuselage upright to finish fuel system and controls in the wing and attach the center section top skins...

    Billski
     
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  4. May 20, 2018 #24

    wsimpso1

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    Time for another report. I have been building ailerons and getting them and the flaps ready for hinges.

    First the ailerons. Hotwired from blue foam, each in two pieces spanwise. The ailerons have twist to follow the 1 degree of washout on the wings. The guy in the balck t-shirt is yours truly.
    IMG_20180216_151109.jpg

    Next is vacuum bagging the bottom skins on. The cutoffs from hotwiring are fixturing for the bagging, and even later used again for sanding the dry micro.
    IMG_20180220_073540.jpg

    After the resin cures, strip the bag film, blanket, perforated ply. Peel ply was left on for a while, except around the nose, where I pulled it off to allow a glass-to-glass bond of the top and bottom skins.
    IMG_20180220_074253.jpg IMG_20180220_132928.jpg

    Then prep for top surface by fitting and bonding in hard foam for hinges and actuator. Actually could not find any 20 pcf foam, so made some syntactic foam (1" thick plate of dry micro) and used it - the white stuff. Then cutout an opening to allow install of actuator mount. The duct tape in a T shape is around some foam that temporarily fills the recess.
    IMG_20180220_134306.jpg IMG_20180415_170743.jpg

    Once it was all ready more vacuum bagging.
    IMG_20180419_102810.jpg

    Somewhere in there, the vacuum pump I have been using since about 2001 (it was a used pump then) started making bad noises, and there are no bearings or other parts, so I built a new vacuum system around a salvaged pump laid on me by a friend. 240 VAC pump with 24 VDC solenoid valves meant a 240VAC line from the box, a 24 VDC power supply, an industrial relay rated to carry the motor, a small vacuum accumulator to allow the motor to get a little speed before it gets to full load, a bunch of hardware and connectors, and a box for the cool stuff. Thanks go to Veneer Supply https://www.veneersupplies.com/categories/Vacuum__Press__Items/Vacuum__Press__Kits/ for his website based plans and parts for building the new pump system. New system is quiet and smooth and pulls down quickly.
    IMG_20180501_091013.jpg

    Next step is fairing and finishing, I will make another entry soon.

    Billski
     
  5. May 31, 2018 #25

    wsimpso1

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    Time for more pictures on flaps and ailerons. I have filled and faired the bottoms of all four, and filled the tops. I checked and the filler is still doughy so, I must do something else until at least the pm.

    First the process. The flaps and ailerons are a little rough. I had vacuum bagged glass over hotwired foam, and the glass is far from smooth - every bit of roughness in the foam telegraphs through to the top, every bit of thickness variation in the knitted cloth shows up, and every bit of excess resin was squeezed through to the blanket and removed, leaving the shape of the glass. There is an overlap at the leading edges to bond top and bottom skins together. At the trailing edge, there is step that puts the skin from one side in contact with the other side. Big depressions are filled "below grade" first with the driest micro you can handle, and the high spots are all knocked down. I also made a first pass at straightening the trailing edges, but I still left 1/16"-1/8" trim stock.

    Pull peel ply, clean, light sanding and primed the surface to be filled with a light coat of dark green epoxy primer from Poly Fiber. It is great stuff, can be handled in an hour, takes a week to fully cure, known to get a good grip on the epoxy part and on the filler. And you can start to see that dark primer when the micro is sanded down to 1/8" thick. Mix dry micro in a plastic bowl with a 3" spatula. Dry, no shiny spots when you let it stand. 6" drywall knife, warm the back of the blade often with a heat gun, lots of pressure, 1/8" to 1/4" thick, lots of fixing holes and peels. It looks like you iced a cake, and but not pretty, but if you try to make it thinner or knock down the ridges and high spots too much, you lift filler, so "you gotta learn when to stop friggin' with it".

    After that, let it stand until hard, and then you sand. Big sanding sticks with 36 grit body file paper. My sticks are made from shelf stock, white melamine coated particle board, with a second part screwed to it forming a "T". I have them in 17.5" and 35" with 36, 80, and 120 grit papers. Glued on with spray adhesive. Heat gun takes it off. Change paper often. When the dark primer begins to look like you will be sanding it, which you do not want to do, you change to 80 grit to get rid of the deep sanding scratches. Most of my work was done with 35" stick. The sound it makes doing the +/-45 strokes is "air-plane, air-plane, air-plane". Sounds that way to me. This is also when I straightened out the leading edge and finished the trailing edge to the line.

    Then you patch any deep scratches with epoxy and West 110 Microlite mixed thick, but not crumbly. Here is a tip - throw a couple little wooden blocks in the container. Give it a good shake to break up clumps. Apply the mix to holes and scratches with small spatula and scrap off excess. After it cures, you hit it again with 80 grit.

    The last step for today's update is to seal the micro. This stuff gets bubbles in it, and the surface is full of little pin holes. They must be filled, and spraying high build primer will not do it. The epoxy wipe is the best method we know of, and it fixes all sorts of sins. I used the same ProSet 125/226 epoxy that I use for structures and filling. Works great. Put it on with a brush and squeegee, wait a few minutes, wipe as much off as you can with the squeegee, let it begin to gel, and repeat four more times. Once cured, you go back and sand with 80 grit to take off the little high spots, then get it all sanded.

    The application of filler and sanding and sealing is covered well in these two sites:
    http://www.ez.org/pages/waynehicks/chapter_25.htm
    http://curedcomposites.com/finish.html
    George kills pinholes by a different method, and is very good reading.

    I did the bottoms first. Why? Well, they are nearly flat - there is a slight twist as they follow the washout of the wing - and they are on the bottom, which makes it harder to see any defects, so I figured I would learn the fairing of big parts there. And I did the first one through to 80 grit before attempting anything else. Here is what the first one looks like filled, but not sanded:
    IMG_20180507_130850.jpg
    Like I said, rough. Because I worked in micro balloons until the micro was dry, it sanded easy. Took me, being a beginner at big parts and checking for flat and straight often, about 90 minutes to get to this:
    IMG_20180511_085430.jpg
    Yeah, hard to see it. Soft white. Lots of dust. Funny thing about the dust - yeah, wear your mask, but it is not itchy and it pretty much falls straight to the floor. Fills the vacuum cleaner quickly too. I did the other aileron the same way, took an hour to sand with 36 grit, a half hour with 80 grit.
    Filled the trailing edges on the flaps:
    IMG_20180514_110448.jpg
    Then primed and filled the bottoms of the flaps, they looked the same way. Each flap took about 90 minutes to sand to shape with 36 grit, a half hour with 80 grit. Then I did the neat epoxy fill of the bottoms:
    IMG_20180515_160026.jpg
    Then the flaps:
    IMG_20180520_092110.jpg
    Now I have prepped the tops of the flaps and ailerons for filling and fairing. Here are the flaps ready for primer. Note the opening in the top of the ailerons. An anchor for the actuator will be embedded in hard foam through that opening and, the pushrod bearing bolted to it in there as well. The foam and glass was inletted to allow a little cover with a hole just big enough for the pushrod to fit flush. Otherwise the process is the same as before.
    IMG_20180529_172506.jpg IMG_20180530_101606.jpg IMG_20180531_072555.jpg
    Yeah, my process for putting on dry micro is improved some. I have hung my heat gun from the ceiling so I can easily and quickly heat the drywall knife for every pass. I still have to fix spots... Now on to sanding the tops and then installing the imbedded hinges. Updates soon.

    Billski
     
    Last edited: Jun 1, 2018
  6. Jun 29, 2018 #26

    wsimpso1

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    OK, sanded my ailerons and flaps, epoxy wiped (five coats) both sides, made and installed hinge pieces and aileron actuator anchors.

    First are the sanded parts. Why am I doing this finishing work now on my flaps and ailerons. Biggest reason is that I am using embedded hinges, and trying to do all of the fairing compound and profile sanding and everything with the hinge pieces in is crazy. So, take these through profiling and pinhole killing now. I will prime and paint them later with the rest of the airplane.

    20180613_204548.jpg 20180613_204558.jpg 20180621_001759.jpg 20180621_001811.jpg

    These parts had been filled with dry micro, which we are supposed to put on thick enough to only do once. Well, on one surface, I had big areas that did not "clean up" when I began to show the dark primer, so I had to go through, sand everything "below grade" and refill... Live and learn. Profiled with 36 grit and the big scratches were removed with 80 grit, all on big sanding sticks. Previous times of about an hour for each aileron and 90 minutes for each flap for 36 grit and less for 80 grit all held up. The photos in the middle are the ailerons, and one has the fixture on it during the cure of the aileron actuator anchor.

    Then I went through with West 410 Microlight filler, which is phenolic microballoons, mixed a thick mix with a little epoxy, filled low spots, bubbles, and incompletely filled edges. This is the pale brown you will see on the parts. The edges will get the corners broken to a tiny radius, but for now, I am fully filling these corners. This tuff sands nice and is not supposed to give as many pinholes. We shall see when I get to primer. I also sanded the ends of the surfaces. After that cured and I hit them all with 80 grit, I killed pinholes. Five coats of neat epoxy are brushed on and allowed to cure, then sanded with 80 grit. Sanding took an hour or more on each side of each surface, and the parts are really starting to look nice... But one turned out to still have too much filler. I had to sand through the neat epoxy and profile down in the dry micro, fill pinholes and seal with five coats of neat epoxy, and sand it again... Sigh. Live and learn again. Only one out of eight sides, not too bad. It is true that we are better off too thick and doing more sanding than having to fix it. Must have spent four hours on fixing each of the surfaces...

    Next is aileron actuators, two of them, 1/2x1/2x0.035 square 4130 steel tube, some more 0.035 4130 to beef up the tabs, and a bunch of 1/4" holes. These get sunk in high density foam with flox. Made a fixture that traces the shape of the aileron at that station with the leading edge, trailing edge, and a hole that fixes the bolt hole in the right spot with a pin. It worked nicely. Just knock the pin out after it cures and lift off.

    20180613_204631.jpg 20180613_204641.jpg 20180614_081605.jpg

    Twelve hinge pieces. Three on each flap and actuator. 1/4" 6061-T6, cut out, drilled for bonding, drilled and reamed for airframe self-aligning bearings, deburred, bead blasted and alodined. Only one required any press at all to get the bearings in, so they were glued in with Loctite and staked. Sorry, no pics.

    Install hinges in the flaps and ailerons. I again laid out the surface profile with the hinge locations, made a simple fixture of each from 1/2" MDF, cut it out, drilled a tight fitting hole for the bolts intended. They required some fitting, but I got them to line up perfect. I had already laid out and cut slots in the bottom skins and the high density foam pieces, but several required a little bit of adjustment. The fixtures were attached with low temp hot glue, adjusted to align the holes. The slots in the control surfaces and holes in the hinge pieces were filled with wet flox, and then assembled and bolts put in. Done right, flox flows out everywhere as you press the hinge piece down and into alignment with the hole in fixture. Done not so right, and you go back with a syringe filled with epoxy and fill the gaps and make everything happy. I have been chasing one slot for two hours... An example of each follows. Yeah, the flap hinge line is quite a bit below the wing, while the ailerons have the hinge line a lot closer to the foil, but still below it.

    20180629_125157.jpg 20180629_125206.jpg 20180629_125217.jpg 20180629_125226.jpg

    So, now you are up to date. Next steps (after the hinge pieces cure and are cleaned up) is to make fixtures (more layout and MDF) to hold the flaps and ailerons on the wing in the right spots. That will allow me to make the fixed hinge pieces, which will be riveted to angles bolted to the drag spars. Pretty stirring stuff.

    Until next time,

    Billski
     
    Last edited: Jun 29, 2018
  7. Jun 29, 2018 #27

    wsimpso1

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    There, fixed the photos and edited the text to make more sense. Sorry about that...
     
  8. Jul 1, 2018 #28

    wsimpso1

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    After all of that effort, I removed the fixtures, centered the spherical bearings, and looked through them. Ailerons are perfect, nice concentric circles. The ailerons will deflect with little friction. One flap is also perfect. The other flap, well, the center one is aft of station by about 1/16". I am wrestling with going to the effort to free that one, make a new one, and install it. See the design area for a discussion.
     
  9. Jul 11, 2018 #29

    wsimpso1

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    So, after hashing it over with folks on here and in my own mind, I removed the offending hinge half at the outer end of the right flap. I cut free the two long sides with a multi-tool and saw blade, and the two short sides with a long 3/32" drill. That only left the resin/flox on the top surface of the hinge half (at the bottom of the hole), or about 7% of the original bonding area. Big crescent wrench, grunting and thumping, twisting and bending. Some more worrying with the multi-tool and long drill bit, and it creeked and cracked and eventually came out. The hinge half was chewed up, so I scrapped it, but the rest of the flap looked fine. No cracks in any of the fairing compound, no cracks inside the inletted hole, it looks like it came out clean...

    20180709_163042.jpg

    Made the new hinge half, fooled with my fixture until it looked perfect, double checked it again, and finally gooped it all up with flox and bonded it in. Now it looks straight. Concentric circles are a good sign!

    20180710_174107.jpg 20180710_175149.jpg 20180710_175139.jpg 20180710_175309_001.jpg

    I dearly hope it looks as good with the fixture removed. Time to go back out and see it it will drink any more neat resin.

    Billski
     
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  10. Aug 27, 2018 #30

    wsimpso1

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    New stuff with pictures: I have been building the hinge halves for flaps and ailerons that bolt to the drag spar. That was way more fuss than I had anticipated.

    Each hinge quarter is composed of a 6061-T6 angle extrusion and a plate, riveted together. I checked out other alloys, even modeled the parts in SolidWorks, I could not get down to the next smaller extrusions and make FOS for riveted joints and in the parts themselves. Angles were 1x1x1/8, most of the plates were 1/8", some had to be 3/16". Lightest part was with AN470 1/8" rivets. The join was longer when strong enough in 3/32 and in 5/32. But there is not much space between the drag spar and the control surface, and I was making each one to fit. The angles bolt on (twelve per side), the flaps and ailerons are jigged in place, and then templates for each hinge are made, part cutout, and then tuned for fit. Every pair of pieces was stamped with BL station and side so I could get them all back together and in place without fuss. Then the rivet hole pattern is drilled in the outer part, and a couple holes match drilled into the inner part. The rest of the match drilling is down off the wing on the drill press and taken up to #30.


    20180807_162009[1].jpg

    A quick look at the jigged flap and aileron on one wing with the hinges cleco'ed together and running. They swing through full travel, no binding whatsoever, and feeling OK.

    20180826_151520[1].jpg

    The hinge quarters on the bench. All of the holes match drilled, the parts cleaned in the bead blaster, Alodine coated, and started on riveting them together. Some rivets would not go yet - can not get at some of them with either the squeezer or my little hammer rig. Going to modify the hammer rig so I can get at all of the rivets and finish them to 0.163" min diameter and 0.050-0.070" thickness. One had to come apart, be reblasted and re-Alodined. Can not get that stuff locally, waiting on mail order...

    Anyway, pretty stirring to have the control surfaces hung, moving, etc. Next step is make the end pushrods for flaps and ailerons, then paint the rods and the riveted hinges...

    Billski
     
    Last edited: Aug 27, 2018
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  11. Aug 28, 2018 #31

    wsimpso1

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    The other engineer in the house has asked more than once why I bolted the hinges to the spar that way and why there are so many rivets in the hinges. She thinks they look horribly overbuilt. This is a good place to talk about that.

    The issue of how to connect the wing to the control surfaces vexed me for a bit. A long time ago I committed to the path of carrying fuel in both forward and aft bays of the wing between BL 55 and BL108. The center 100 inches of the wing is built into the fuselage and then outer wing panels attach to the center section. Access to the center section is needed, so no fuel stored there. 25 gallons a side would not fit in only the portion forward of the spar, and an equipment bay or two is needed in the bay behind the spar for aileron control, pitot static probe, and AOA probe. So fuel goes both forward and aft of the main spar from BL55 to BL108.

    In foam wings, common practice is to put in a block of high density (20 pcf) foam at each hinge point, set hinge halves in the control surfaces in high density foam (as I have done) and then embed pieces in the foam. Nice if you know that the pivot points for the control surfaces will not have to be shifted. I do not. Flaps will probably be OK, as those positions give me the lip overlap and slot thickness that is preferred with a slotted flap. Aileron hinge lines are at about 22% of aileron chord, which is a guess based upon RV's - If the aileron forces and general control harmony are off, I can build a new pair of ailerons with altered hinge positions, but to change the wing mounted halves would be much harder. Besides risking the high density foam blocks inside the fuel bays, how do you change the hinge halves for some with the hinge line in a different place?

    I went with phenolic hard points in the core of the drag spars at each hinge location, used ClickBond floating nut plates on the inside, then put a piece of 6 pcf Divinycel over it and sealed it up with glass, extra resin, and the Dow tank sealer that also sealed the rest of these bays. Cool, now I can switch out the hinges if need be.

    Next step is design of the fixed hinge halves, After looking at the in flight loads and deflections of the flaps and ailerons under 6 g pulls and full aileron at Va, I concluded that I needed three hinges per control surface. I also made the slightly conservative estimate that the center hinges carried about half of the load of each with the ends each carrying a quarter. The shear and moments at each hinge base and at the joins between angles and plates were impressive.

    Two 1/8" aluminum plates in 6061-T6 would keep my FOS in the plates above 1.5. Checked out 2024 and even 7075. Could not get down to the next thinnest stock with them. Then looked at the angle stock, and had the same issue, so 6061-T6 it is. Then I benchmarked similar hardware. That is fancy talk for I checked what the other guys are doing, just to see if somewhere I had gotten all wet. Everyone else with 250 knot Vne and similar wing loadings has similar structures and weights.

    Set up a standard fastener study for each join and looked at how many rivets with 2d edge margins and 3d rivet-to-rivet margins would be needed in everything from 1/16" to 3/16" rivets. I required FOS of 4 for the rivet designs. The overall joints were smallest in 1/8" rivets. The plates carry those moments right up to the rivets. In a couple places I had to whittle the plate and angle to get control clearance, which changed the rivet patterns and caused a revisit on the whole rivet calc process. Then I modeled each of the hinge quarters in SolidWorks. Everything was OK at FOS of 1.5 except the flap inners and the aileron inners. The flap inners have lift and actuator inputs and the actuator inputs have a significant lateral component. The lateral deflections looked kind of big with 1/8", but much smaller with 3/16", so that was that. The inner ailerons were whittled for clearance, and they ended up being 3/16" for both stresses and deflections too.

    So then came jigging the control surfaces with wing templates at the edges of the control surfaces, hot glue to keep things in place, cardboard templates, sawing out pieces, removing excess material, lots of time with the 1x30 belt sander and a 40 grit belt. When everything fit, the initial holes between plates and angles were drilled and cleco'ed and then surfaces were mounted and swung. That was a big moment on each side. Then everything was pulled, sanded to 120 grit with sanding marks parallel to the long edges, abrasive blasted, Alodine coated, and assembly started. That was when I discovered I could not fully set 1/8" rivets with my squeezer and that I could not set all of my rivets with either the squeezer or my hammer rig... Modifying my hammer rig so I can fully set 408 rivets. Not looking forward to that, I have tendonitis in my strong arm with the muscles used for gripping said hammer.

    Anyway, that is how they came to be kind of beefy looking.

    Billski
     
    Last edited: Aug 28, 2018
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  12. Sep 20, 2018 #32

    wsimpso1

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    Aileron pushrods made and they work. Neat. Setting them aside for paint.

    Flap pushrods are really short - two spherical rod ends, two jam nuts, and about 4" of Grade 8 1/4-28 rod. The slots in the fuselage wall to go from the flap walking beam bellcrank (inside the fuselage) to the fitting on the end of the flap (outside the fusealge) are another matter. Transfer the position of the inside bellcrank to the outside as well as I can, then drill a little hole, enlarge and shape to first get the connection when stowed, then a slot to allow for travel of the bellcrank and flap. No small amount of fussy work for that.

    Flaps are slotted flaps with off wing hinges (a couple inches below the bottom skins), and according to most of the sources, including TOWS, that means a faired shape for the slot, leading to a lip about 1% of chord deep and about 1% of chord overlap on the flap. The hinge position was chosen to give 50 degrees of flap and the specified slot. I was fortunate in that the hinge position also gave substantial aero balance to allow easy actuation without over balance. The lip is being formed by the previously shaped upper skin, while the radius and faired shape to the lip is being made with a bit of polyurethane foam, glued to the skin and drag spar with dry micro, then formed to a nice shape and barely clear of the flap with sanding sticks. Then 2 BID covers the foam with an overlap from the bottom surface of the bottom skin to the lip on the bottom surface of the top skin.

    A similar plan is in place for the ailerons. While I built the control system to have about 2:1 differential aileron travel, but who knows, I might find that excessive and build new bellcranks that decrease that ratio. In which case the aileron down motion would increase. I stole a page from the RV's and the hinge is about 22% of the aileron chord and just barely below the bottom skin. This ends up making a bit of a slotted flap aileron out of it. Might as well have a decent form, so it is shaped too, with a lip.

    Then comes the fun part. The wing is fuel tank from BL54 to BL108, and from the drag spar to the vestigial front spar. I put an internal NAV antenna on each wing with the vertex at the aileron equipment bay, and the open end of the dipole forward. Nothing but fiberglass that way, they should work fine. The wiring and plumbing (for nav lights, strobes, landing lights, NAV antenna, pitot/static, and bonding) all runs along the drag spar under the faired shape. Well, the room between the spar and fairing and hinges bolted to the drag spar and the Allen wrench access for the hinges is kind of tight. It is fine through the flap slot fairing, but around the aileron hinges, well, I have to forgo the irrigation plumbing I was originally intending and use braided tubing for the chase. It is pretty tight, but it will work. Gotta install the wiring and braided tube and plumbing before attaching the PU foam to make sure the braid is in the right place and will stay put. The PU foam over the inner aileron hinges was put in place, shaped, sanded, and glassed, then foam was sanded away for the braid. Waiting on the braid and bonding strap. I will install the rest of the fairings after...

    So, other things to do while I wait. While doing the wiring, I bought fittings for connecting wiring and plumbing. Went with 1/8 x 1/16 tubing for pitot/static and AOA, with quick connect fittings at the probes and at the wing junction. I also bought some of the Duetsch sealed wiring connectors. Still have to buy a pin swaging tool for them.

    Aileron balance. Well, they must be 100% balanced. I decided to just ballast the nose section. It pains me to have five pound ailerons turned into eleven pound balanced ailerons, but the alternative is weights on arms at the ends, messing up the faired tips, more aero balance than I might otherwise want, etc. I looked into making lead rods, but did not like the poor fit and amount of epoxy they would need and how they might need to be pretty heavy as I could not readily get them as far forward as the shape allows. After some head scratching and calculations, I ordered some reclaimed lead shot. Yeah it has to be washed to use it and is effectively lower density thus maybe a little heavier than solid rod. I guess I am cheap... My ailerons are hotwired blue foam. I have a space on the very leading edge of the ailerons that will take the balance weight. Ran a 7/16" tube on a drill from the root end to near the tip end of each aileron. I had figured I would need more cross section than that, but hear me out. Put a long tiny tube in the long hole, and use a syringe to inject gasoline into the space, then use the same tube to blow air through to remove the gasoline. That enlarged the space enough to get a full charge of shot and epoxy inside. Not only that, by orienting the flap with the leading edge "down" during the gas dose, all of the foam at the leading edge was collapsed. Yeah, I know, shot and epoxy is not as dense as lead rod, but by nesting the shot and epoxy against the inside of the leading edge, I got it further forward than I would have been able to other wise. It calculated out to less total weight that way than with some lead rods that are not as far forward. They are sitting in the shop, leading edge down, with only a few loose shot. After it all cures, I get to check balance. If need be, there is still some space near the root end of each aileron to add some more weight or to drill some off after paint.

    So , that is where I am...

    Billski
     
    Last edited: Sep 20, 2018
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  13. Jun 13, 2019 #33

    wsimpso1

    wsimpso1

    wsimpso1

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    It has been a while. Lessee, besides some issues with the left eye (resolved), there was OSH 2018, Sun-n-Fun 2019, Ladies-Love-Taildraggers fall tour (I sat right seat), snowboarding, rehabbing two bedrooms, the master bathroom, and the fireplace. There was probably more, but I did get some airplane building done.

    Let's see, I installed foam in the cove near the flaps and ailerons on the outer panels, left room in them for the wiring for position-, strobes-, and landing-lights, antenna cable, three 1/8" tubes for pitot, static, and AOA. The wires and plumbing are collected at the BL108 equipment bay. A conduit penetrates the drag spar there, runs behind the drag spar in the cove fairing until BL54 where it comes forward through the drag spar so it can be connected in the stub wing to the rest of the airplane. Once I had all the wiring figured out and installed, I covered the conduit with PU foam, shaped it nicely, cut it out for the flap and aileron hinges, and then covered it all with two UNI at +/- 45. Balanced the ailerons too.

    Then was making and installing the tunnel in the baggage bay and it various covers to keep the baggage out of the controls.

    I worked out and bought the pieces for most of the rest of the fuel system. Then I brought the fuselage upright and hung the right wing, put in the inner glass tapes to fix the stub wing lower skin to the spars and fuselage. Yep one access panel in the aft bay (wing attach bolts, fuel lines, wiring, fuel level gauge) and one access panel in the forward bay (low fuel warning switch, more attach bolt access). Then started fitting the stub wing upper skin.

    That is enough for this page.

    Billski
     

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  14. Jun 13, 2019 #34

    wsimpso1

    wsimpso1

    wsimpso1

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    Continuing, I designed and built a new setup for the rudder pedals. As it was, the cables for the outside pedals were about 4" off the outside fuselage walls. Now they are within about 1/2" of the walls, much less likely to be snagged. I also changed from two supports per side to one. In total, I got a better system and saved six pounds. Illustrated is a support in its jig for tack welding, the layout of the new outer pedals, a pedal in its jig for tack welding and the finished product back from powder coating.

    Then there were seat pan pieces being laid up, and new aileron bellcranks. The previous seat pans were heavy and bound on things. Design slightly modified new ones and have them going. I ran FEA on my original aileron bellcranks, did not like what I saw, and came up with new ones that won't be flexible flyers, but still fit in the same places, and surprisingly are only an ounce heavier.
     

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  15. Jun 13, 2019 #35

    wsimpso1

    wsimpso1

    wsimpso1

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    Now to come up to date. Fuel and wiring and other plumbing has to come from the outer panels to the fuselage. The aileron linkage also has to go through too, which makes the last bay of the stub wing kind of busy. In total, there is power for position lights, strobe lights, and landing lights to the wing tips. There is also power for electric heat at the pitot tube, a coax cable for the NAV antenna, and the 1/8" tubes for the pitot/static system. There is a conduit to the tip, a short conduit between bays, a long conduit from the BL108 equipment bay back to BL54 through the cove fairing for the ailerons and flaps, and then the bundle goes back forward into the access bay. There will be three Deutsch connectors, a BNC connector, three 1/8" tube connectors, and two 3/8" fuel lines (one supply, one header vent), the mini BNC cable from the Princeton fuel level gauge, its signal processing/calibration box and wiring, and a wire that ends up going to the low fuel level switch in the forward bay. In the forward bay, we also have a Deutsch connector for the low level warning switch.

    So, here is the space for all of that. Using AC43.13 for guidance, fuel should be lowest, all wiring above the fuel. So, fuel is aft and low, wiring will be above it and forward, the Princeton signal processing and calibration box will be attached to the upper skin on a couple ClickBond studs. 3/8" fuel lines need support every 16" and near that valve too. My wiring/etc bundle needs support every 12" when not in a conduit.

    I have come to the conclusion that I will be using ClickBond studs and Adel clamps to secure most of that stuff, plus maybe a fiberglass fabricated angle bracket or two as needed. From the outer bay to the fuselage the wiring will go in a conduit

    More when I make some more progress.

    Billski
     

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