cowlove

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  1. cowlove added a post in a topic Source for flaperon bushings? Or stock material suggestions?   

    I just tried turning down the 7/8" bushings to the required 13/16", with fairly unsatisfactory results. 
     
    I think I'll give the milk jug idea a try while I search for 1213-12 bushings.   Anyone have any more stories or hints about the soldering iron finish when making these? 
     
    Jim
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  2. cowlove added a post in a topic Source for flaperon bushings? Or stock material suggestions?   

    EDIT: Please see post below, these part numbers and measurements are wrong. 
     
    I also ordered some Igus RFI-1214-12 to experiment with.  They are some sort of unspecified low-friction polymer.  (But definitely not a PTFE or Rulon, based on the price.)  
     
    I'll be keeping a super-close eye on the whole flaperon area as it is (I did rib tail reinforcements and made new fiberglass flaperons), so it'll be easy to watch the bushings for decent wear and material compatibility, etc. 
     
    J
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  3. cowlove added a post in a topic Source for flaperon bushings? Or stock material suggestions?   

    EDIT: Please see post below, these part numbers and measurements are wrong. 
     
    I ordered McMaster-Carr part # 6389K555, although it's too long, its available in 5-packs at a fraction of the cost of the 3/4" long proper size and I'll experiment with cutting it down. 
     
    Grainger part # 2NCL2 seems like a perfect fit, but was a longer delivery time.   
     
    Then I learned that there's a standard numbering scheme for bushings.  "XXYY-ZZ", where XX is ID, YY is OD and ZZ is length in 16ths inch.  
     
    Using "1214-12 bearing" in searches turns up a ton of manufactures and vendors... including Walmart and ebay. 
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  4. cowlove added a post in a topic Source for flaperon bushings? Or stock material suggestions?   

    <blink>MISINFORMATION ALERT</blink>  I apparently had not a single awake brain cell when I had the micrometer in hand and measured the stock bushings.    The OD of the bushings (and thus the hole in the hanger bracket) is 13/16, not 7/8.   The proper bushing family would be 1213-12, not 1214-12.  Which are a lot harder to find than the 1214's.
     
    The milk jug looks like a very real possibility.  
     
     
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  5. cowlove added a post in a topic Accidental takeoff during step-taxi testing in the Catalina   

    I used to do computer stuff, so I used a bunch of homebrew scripts the use freeware tools to make the embedded graphics.   The orignal data comes from a little homebrew EFIS computer that collects engine stats, AHRS, GPS, and air data.   The real first flight may never happen in a timely manner, but when it does, it will be well instrumented and documented
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  6. cowlove added a post in a topic Source for flaperon bushings? Or stock material suggestions?   

    I will collect pictures of the flaperon project and make a little web post, but here's the skinny version-  original flaperons had many loose pivot tube rivets after the cross-country trailering of my plane.  In hindsight, I should have drilled and re-riveted the flaperons right there on the plane, but instead I disassembled them, and became dissatisfied with the original build quality.  I decided it would be fun to play with fiberglass, and would be a great chance to cut weight, as lighter flaperons would earn a double bonus of lighter mass balance weights. 
     
    I messed around quite a bit with hotwiring my own clark-y 11.7 airfoil shapes, but ended up ordering 20 3' blanks from Eureka CNC.   Each 15' flaperon was laid up in one piece, with cutouts and flox hardpoints every 3' for a hanger pin to replace the torque tube, and hardpoints at the inboard ends for the original flaperon control horns.   It took a couple hundred hours and they did not end up being the beautiful, mesmerizing works of art and engineering that I envisioned.  The finish is mediocre and the brackets look hokey. 
     
    But they're light, and have better pre-existing balance than the aluminum, so the balance weight is only 200g per side.  Total weight savings is probably about 11#.  Overall, I wouldn't do it again. 
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  7. cowlove added a post in a topic Source for flaperon bushings? Or stock material suggestions?   

    Disregard.  If you call them flanged BEARINGS, not bushings, they show up all over Grainger or McMaster Carr. 
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  8. cowlove added a topic in Technical tasks   

    Source for flaperon bushings? Or stock material suggestions?
    I'd like to replace all my bushings, as they don't quite press-fit into the flaperon hanger as they're supposed to.   Anyone know of a source, or of a good stock to make my own?  Nothing jumped out right away looking for 3/4" ID 1/16" thickness nylon. 
     
    Jim
     
    Avid Catalina
     
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  9. cowlove added a post in a topic Accidental takeoff during step-taxi testing in the Catalina   

    I got a lot better at keeping it on the water  Her water handling continues to impress me, and it's good experience exploring the... ah... interesting trim/attitude response to throttle inputs.   For the record, the big throttle changes in this video aren't a normal course of action- I'm just getting a feel for said pitch/yaw changes.    Getting there!
     
    http://youtu.be/ByxihXovej8
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  10. cowlove added a post in a topic Accidental takeoff during step-taxi testing in the Catalina   

    Yeah, I'd definitely studied up on both sides of the debate for/against high speed taxi tests.   The plane felt very stable and docile on earlier slower step-taxi tests- absolutely *GREAT* water handling qualities and beautiful roll control.    Given that, I opted for the set-back plan in case of accidental takeoff.  
     
    I rehearsed the response a good bit-  making a gradual power reduction while holding a stabilized attitude.  Alas, when the moment came, I chopped the power like a madman and oscillated in pitch a little bit before just freezing the attitude and letting it sink onto the water pretty hard.  
     
    The glassy conditions may have been another strong factor for opting for the go-around plan, or for waiting for another day. 
     
    Lessons learned!
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  11. cowlove added a post in a topic Accidental takeoff during step-taxi testing in the Catalina   

    ...and I'm definitely not a pro, but I think the high speed taxi question is pretty different for a seaplane.  Water handling qualities are such an unknown and (in my mind) have so many more variables, I think it's pretty important to be comfortable all through the envelope before committing to a water landing. 
     
    The advice I got from some local EAA guys was to treat the thing like a jet ski for a month and put 10 hours on her exploring water handling before even thinking about flying.  I'm now at about 2 hours, and I think that's still the plan.   With a closer eye on the airspeed indicator, and a speed limit of about 35 KIAS!  
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  12. cowlove added a post in a topic Accidental takeoff during step-taxi testing in the Catalina   

    Liftoff was at 45 seconds on the chart, at about 42 knots airspeed. The throttle was abruptly closed after about 1 second in the air, and the clumsy finish of the flight is readily visible as a 2.1G impact after 6.1 total seconds in the air. The smaller series of acceleration spikes before touchdown is a sequence of pilot induced oscillations after the pitch change caused by the abrupt power cut.   Maximum height was probably about 4 feet.  
     
    I was not monitoring the airspeed as closely as I should have, the water was glassy smooth and I didn't have any good indication that I was accelerating that quickly at such a modest power setting.   That thing gets of the water a lot easier than I thought! 
     
     

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  13. cowlove added a post in a topic Accidental takeoff during step-taxi testing in the Catalina   

    ...and it's a good friend who will come find you at the bar and bring you a NASA Form 733
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  14. cowlove added a topic in Avidfoxflyers General Hangar   

    Accidental takeoff during step-taxi testing in the Catalina
    I was checking the flaperon rigging/balance by doing an extended step taxi at about 5300RPM, and she just hopped right off the water.  By the time I stabilized the attitude, reduced power, and let her back down, she was in the air about 4.5 seconds.   
     
    I was half-smart, and had listened to all the advice to be prepared for inadvertent flight before any high speed taxi.  I had adequate fuel, the plane was mechanically airworthy, and pointed in a reasonable direction.   However, the plane's annual condition inspection had expired, so I filed a NASA form 733 describing the incident. 
     
    ...and then changed into clean underwear
     
    At least I'm not in bad company.  Happens even to the pros-
     
    https://www.youtube.com/watch?v=UYy5CGHbrtk
     
    http://youtu.be/Lrb5vWZSCrs?t=2m29s
     
     

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  15. cowlove added a post in a topic Finished and installed fiberglass flaperons. Nice, but I wouldn't do it again.   

    Home-rebuilt 582 grey head with no updates, C gearbox, RK400 clutch, 70" 3-blade warp drive.   Just looking at the numbers, I thought it would take just the right touch to get it off the water.   However, I took it out for some step taxi work to check the flaperon rigging, and had an accidental 4.6 second flight.  It took right off at about 5300RPM(!)
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  16. cowlove added a post in a topic Finished and installed fiberglass flaperons. Nice, but I wouldn't do it again.   

    ...also visible: wing skin patches from surgery to reinforce the rib tail flaperon attach points.  
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  17. cowlove added a topic in Avidfoxflyers General Hangar   

    Finished and installed fiberglass flaperons. Nice, but I wouldn't do it again.
    Finished installing fiberglass flaperons for the Catalina.  Clark-Y foam cores cut by Eureka CNC, 2 layers 6oz cloth, flox hardpoints for hinge bracket bolts.   Exceeds the strength of the original design in several arbitrary destructive tests. 

    Would not recommend.  Cost, labor and time was ridiculous compared to the weight savings.  
     
    Also, in hindsight, I think it's a little too fine a shape to easily work in fiberglass.   As ugly and unsatisfying as reworking the original sloppily-built aluminum would have been, that was probably the better choice.  

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  18. cowlove added a post in a topic Prop slipping on Rotax 582 w/ C gearbox?   

    Boo.   Measured the rotational inertia at about 6300kgcm^2.   Well, that pushes me towards the adjustable pitch propeller sooner rather than later.  Sad that I probably won't be able to re-use the WarpDrive blades with a FP hub.
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  19. cowlove added a post in a topic Prop slipping on Rotax 582 w/ C gearbox?   

    Well, my the last assembly attempt held through two quick full throttle bursts.  I'll have the entire engine break-in period and some pretty extensive water trials to convince myself that it's solid. 
     
    It's the warp drive 3 blade, square tip, with nickle leading edges.   After the plane is flying, I'm going to assess how it gets off the water.  I'm definitely not near that point yet, so hesitate to spend to much time thinking about it,  but two tricks I might consider would be one of the adjustable propeller hubs and a Rotax Rick 670 conversion.   If I do end up shopping new props, moment and weight will definitely be a prime factor!
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  20. cowlove added a post in a topic Prop slipping on Rotax 582 w/ C gearbox?   

    That's a Warp Drive 70".  I don't know how it compares to other props, but that's an idea worth looking at.  
     
    J
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  21. cowlove added a post in a topic Prop slipping on Rotax 582 w/ C gearbox?   

    I'd love to see the documents that you have.  It looks like after the change in '91 to a 7.5:1 cone, they issued a SI in '06 suggesting adhesive compound and a higher torque, then changed the part again in 2008 to a 1:10 taper (so an even shallower cone) and upped the nut torque even more for all part numbers. 
     
    While I had it apart, I identified the cone as described in the '08 SI, and it's indeed the 7.5 cone, which coincides pretty well with the date of the unit. 
     
    So I cleaned everything perfectly, took a stone and applied a pretty axial hone pattern on all the friction surfaces, used AC648, and warmed the gear to 350degF in the oven before pressing it on.  I set the nut with thread lube, a greased flat washer and a very liberal interpretation of 220ft-lbs of torque, then removed it, cleaned the threads, and did final assembly it with loctite, the serrated washer, and the proper torque. 
     
    In short, I did about everything I can think of to help the existing part work.  If it slips again, the way I see it, I've got no choice to buy new parts.  And then I might as well upgrade to an E gearbox and a slipper clutch  Sigh. 
     
    J
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  22. cowlove added a post in a topic Prop slipping on Rotax 582 w/ C gearbox?   

    Thanks!  I'd read one earlier SI about retaining compound and higher toruqe, but had missed the later one about the new part.   I'm sure I have the old part- it's a 95 and the gearbox was probably never opened.   
     
    Here's the SI discussing the part changes:  http://www.rotax-aircraft-engines.com/portaldata/5/dokus/d04298.pdf
     
    The new gear and gone does indeed add up to about $600.  Ouch indeed.  
     
    The later SI advises a higher ever torque setting and normal flat washer for all previous part numbers, so I'll try one more time with the extra kick.  I might warm the gear to about 300 degF in an oven- by my back of the envelope calculations, that would fit tighter by about as much as an extra 1/5th turn of the nut, but without the stresses on the nut/cone/threads that overtorquing it would impart.
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  23. cowlove added a topic in Rotax and other engines   

    Prop slipping on Rotax 582 w/ C gearbox?
    While running the Catalina a few times to tune the prop pitch in anticipation of engine break-in runs, I noticed that the prop is slipping slightly.  Never enough to notice it directly while running, but some index marks I made between the prop shaft and the PTO shaft seem to be creeping during any run that I applied momentary full power to check static RPM.   
     
    I was fairly certain this wasn't acceptable, so I tore down the gearbox ($180 special puller, check) and reassembled the friction cone, adhering to the service bulletins on the topic (increased torque for the big nut, loctite adhesive compound on the cone surfaces, etc).  
     
    It still slipped.   I tore down the gearbox again, this time taking every step I could to make sure surface prep, adhesive compound, and fastener torque was as good as I could make it.  I fully torqued the nut without the lock washer and with thread lubricant, to ensure the gear was as fully seated as it could be with those wrench settings, then cleaned the threads and replaced and torqued the nut with the specified loctite.  
     
    It still creeps.  
     
    I still assume this is not acceptable, but I thought I would verify.  Is the friction cone designed for some creep?  
     
    Didn't think so.  Back to the workbench. 
     
    J
     
     
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  24. cowlove added a post in a topic Installing finger strainers on Catalina fiberglass tank? Options?   

    Thought I would add my fancy fuel diagram to illustrate my description.   Since I spent so much time on it, I want to show it to someone
     

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  25. cowlove added a post in a topic Installing finger strainers on Catalina fiberglass tank? Options?   

    I fitted the homemade finger strainers, and am pretty happy with the results.  I added inspection covers directly under the fuel tank bungs so that they will be very easy to remove and inspect.  If there is residual fuel in the tanks because the lower part of the strainers are clogged, these inspection covers would make it very easy to catch the pour when the fittings are removed.   There's an inline fuel filter on each side before the fuel lines join together and go to the fuel pumps.  
     
    Ditto the thoughts on fuel flow gauges.  When I'm able to watch both fuel flow and pressure, I feel like I have my finger right on the pulse of the fuel system.  Very comforting. 
     
    I added an electric standby pump in parallel with the Mikuni pump, with external check valves after both pumps.  Given that there's a completely redundant fuel path, I was comfortable putting a fairly cheap gear-based gas/oil flow meter in line with the main pump.   I would *not* put such a meter in the only fuel path.  
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