cowlove

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Everything posted by cowlove



  1. cowlove added a post in a topic First flight follies   

    EDMO, Re: trim tab sizing. 
    I'd heard that rule of thumb too, and I'm pretty sure the trim tab is currently a little on the small size, with plenty of room to meddle before the thing becomes too inefficient or looses additional effectiveness.   I'll take exact measurements of the relative area next time I'm at the plane. 
    With the current design, the piano hinge is on the lower side, meaning upward motion of the tab is fairly limited by binding.   The most improvement from making a new tab may be just rearranging the hinge or the tab shape to allow more symmetric range.  
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  2. cowlove added a post in a topic First flight follies   

    I never installed my water rudder, but have found the plane always has excellent rudder authority with a little bit of power.  It's practically vectored thrust with the tail right behind the prop like that   I have nickle leading edges and don't worry too much about prop abuse, so in a pinch I can add more power.   If I'm in close quarters or feel like I need a ton of control, I extend the landing gear, which act as a very effective water brake and allows the safe application of even more power, and also moves the center of hydrodynamic pressure a little aft, helping the plane turn away from the wind.   With full flaps, there's also quite a bit of adverse yaw in the beneficial direction when hold your ailerons into the wind.  
    If all this didn't get the plane under control, I am guessing the water rudder wouldn't be any additional help.  
    These tricks are a little unconventional, but I've found the Catalina's water handling to be amazing.   More jet-ski than airplane. 
     
     
     
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  3. cowlove added a post in a topic First flight follies   

    PS- I also added vortex generators to the underside of the hstab to try and get a little more pitch up authority in the forward-CG limit.   It's right at the barely-acceptable limit with the power at idle.  
    So as it stands, going from solo minimum fuel to dual minimum fuel takes me from one extreme end of the CG envelope to the other, and luckily the controls, rigging and trim are just within their limits in both cases.  
    Running out of nose-down trim and the fwd stick location is more annoying on a daily basis, but I think running out of up elevator authority in the flare of an engine-out landing with a buddy on board would be more consequential .   I'd rig to solve the latter case, and use workarounds and creativity to deal with the former problem.  I believe Jack down in TX made a little weight bracket on the floorboard that he can slip a 25# weight plate onto.    I'm considering a bigger foam core/fiberglass trim tab.  (Lighter and more aerodynamic while I'm at it.)
     
     
      
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  4. cowlove added a post in a topic First flight follies   

    When flying my Catalina at aft CG, I run out of nose-down trim at my cruise speed of about 75MPH.   I'd test the full CG range before you make any changes though.  With a heavy passenger and minimum fuel, the CG is at the forward limit, and I'm glad I have every bit of that hstab incidence .  
    I think the flaperons have much less pitch effect than on the other avid birds.  I can't imagine trying to trim out my Catalina using just the flaperons.   I think the CG range tends to be a lot bigger with the Catalina, and the trim forces much larger.  
    Anyway, your performance numbers look amazing.  I'm about 1050# solo and get 75MPH cruise at 600fpm climb on a good day.  What's your motor?  Obviously something a little more fit than my tired 582.
     
     
     
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  5. cowlove added a post in a topic Rotax 582 Grey Head For Sale   

    "In flight adjustable carbs"... Like a throttle cable?  
     
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  6. cowlove added a post in a topic Catalina weight and balance   

    I did make the spring.  I just ordered some flat bar aluminum, did some back-of-the envelope calculations to design it for about the same ultimate strength as the steel spring, tested it, and called it good.   It has much less energy-absorption than the steel spring did, and of course there are big drawbacks to using aluminum in this fashion- it's almost an unsuitable material for a spring.  I wouldn't recommend it.    But it's just a placeholder until I can lay up a proper fiberglass spring this winter.  
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  7. cowlove added a post in a topic Catalina weight and balance   

    And I settled on testing a CG range of 11.185 to 16.75. My plots of stick force and stability showed that it could go a bit more rearward, but I have no need to explore that unless I start losing weight. Or get a heavier tailwheel setup.
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  8. cowlove added a post in a topic Catalina weight and balance   

    I would love to look at a 600# Catalina and see how it's different from mine.   Your performance must be incredible!  I'm at 746#, 25.07" CG.   That's 582 grey head, after significant work to bring it down from about 830#: fiberglass flaperons, fiberglass floorboard, rear seats & floorboards stripped out, no cushions, oil injection and tank removed, 2 pound LiFe3 lithium starting battery, aluminum tailwheel spring, water rudder removed, completely required with thin-gauge wiring, etc, etc.   
     
     
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  9. cowlove added a topic in Avidfoxflyers General Hangar   

    Mercotac mounting w/ Ivoprop IFA - Anyone have those instructions that are mentioned in other threads?
    Hi guys- I've had an 72" ultralight ivoprop off and on my 582-powered Avid Catalina, and just got a Mercotac 205-HS so that I can do away with the slip rings.  (About $50/each including some fittings & shipping, for those who were asking about prices in other threads.) 
    There are some hints on the forum about some instructions someone had made; does anyone have them laying around?  
    I'm hoping to see some ideas for mounting the mercotac into the prop shaft.  The mercotac is designed to press-fit into a 1/4" ID hole, and the hollow prop shaft looks to be about 5/8" ID. My current best idea is to make a little HDPE bushing and glue it in with epoxy. 
     
     
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  10. cowlove added a post in a topic Fueling Options   

    I've been using these: http://www.amazon.com/Sierra-Tools-Battery-Operated-Liquid-Transfer/dp/B000HEBR3I/ref=sr_1_2?ie=UTF8&qid=1456823678&sr=8-2&keywords=fuel+transfer+pump
    They're a *very* cheaply made transfer pump that runs off 2 D cell batteries.  I do still have to lift the 5-gal gas can up onto the wing, but then can just leave it there unattended while it transfers.   The price is right ($16 or so).  I would guess that one set of batteries transfers about 50 gallons.   I'd tried the 30 gallon fuel tote, hand-crank pumps, setting the can on a ladder and letting it siphon, modifying cans to pour faster, etc... and I'm happiest with this.
     
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  11. cowlove added a post in a topic Ivo in flight adjustable on 582   

    EDMO: Yeah, the 3 blade 72 is too much prop for the 582 for sure.  I got the blades anticipating the Rotax Rick 670 this spring.   I'm guessing with the 670 and landing gear doors, the thing won't stay on the water long enough to put even the slightest bit of additional wear on the blades   Until then, I'll troll around with the Warp Drive. 
     
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  12. cowlove added a post in a topic Ivo in flight adjustable on 582   

    I had both 2 and 3 blades on a IVO IFA UL hub and 2.62 C gearbox on my 582-powered Catalina.   The 72" 2 blade IVO setup let me dial in the most efficient cruise I've ever got from the plane, but couldn't quite match the static thrust of the prior 3-blade 70" Warp drive and a 3.00 gearbox.    The 3-blade 72" IVO had obnoxiously huge static thrust running right at redline, but I don't think I could quite dial in the cruise performance of the Warp drive.   It's a little too much prop for the 582, I got the setup planning to move to a 670. 
    It was a whole lot of fun to play with in the air.  I loved having a backup plan if EGT's got a little high.  Just a nudge of pitch would bring them right in line. 
    Alas, the IVO blades don't hold up to water spray very well, and I've switched back to the Warp drive with its bomber nickle leading edges until I make some improvements and don't have endless 90-second water takeoff runs at full gross anymore. 
     
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  13. cowlove added a post in a topic Don's Catalina Thread   

    Don, did you notice any cruise speed improvement w/ the radiator and/or landing gear doors?     
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  14. cowlove added a post in a topic Don's Catalina Thread   

    PS- Ditto on what others said about the windshield.  Makes the poor Catalina look almost half sexy. 
     
     
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  15. cowlove added a post in a topic Don's Catalina Thread   

    Nice plane, Don!   It has some great ideas in it.  I really like the gear door idea- I was just noticing a few days ago how much drag the open wheel well has.   I also like the inboard radiator mount- could you post some detail pictures of the gear doors and the radiator install?! 
    Thanks in advance!
    Jim
    Catalina #157
     
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  16. cowlove added a post in a topic TRANSPONDERS, MODE C or S needed?   

    I got the Trig TT-21 and am super happy with it.  It's under a pound, fits a 2 1/4" hole, and is ADS-B out/1090ES capable once you hook it to any GPS position source.   It was a little on the pricey end, but I was/am very weight and space conscious.  
    Jim
     
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  17. cowlove added a post in a topic Yup, Did a Dumb   

    I'll just chime in with another "don't feel bad, I did it too."      
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  18. cowlove added a topic in Rotax and other engines   

    Rotax 582 Bings spitting fuel - carb bowl venting problem?
    For two years, I've had problems with fuel overflowing out of the carb jets when I first pressurize the fuel system, especially if the carb bowls were drained to begin with.   I tried everything I could think of, including:
    reducing inlet fuel pressure replacing float valves several times adjusting and tinkering with the floats every which way to encourage quick action.  About half of the time, fuel would continue to freely flow out the jets and the carb float valves wouldn't seat until I shut down the pump and let things settle for a couple seconds, then tried again.    Obviously not acceptable
     
    I finally noticed that it didn't happen when the carb vent tubing was removed.  I experimented, and sure enough, could reproduce it 100% of the time with the prescribed "pinhole in a tube" carb vent, and could never reproduce it if the vent port was unrestricted.  I ended up using unrestricted 1/8" line into a small breather air filter as a vent, and things have worked great.
     
    However, now I want to add a hacman-style mixture adjustment, which by its nature requires a vent port that's restrictive enough so that you can draw bit of a vacuum against it to lean out the mix.   I'm scared to tread into this territory without understanding why restricting the vent port earlier caused an engine-disabling problem.  
     
    Does anyone have experience with these symptoms?
     
    Thanks!
    Jim
     
     
     
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  19. cowlove added a post in a topic Avid Catalina N157AB's first flight out of KRNT, well over 2 years after I first said, "two weeks!"   

    AFF1- Yes, I have a 582 in it.  For the last two years, I'd been practically planning an immediate motor upgrade, thinking that I would obviously need more power, but it gets right up off the water and climbs 500fpm at 1200#.   Who needs more power?!
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  20. cowlove added a post in a topic Avid Catalina N157AB's first flight out of KRNT, well over 2 years after I first said, "two weeks!"   

    Video of flight number 3 has been destroyed...  Just kidding.   Nothing major, just got a little surprised by some of the handling characteristics with flaps down.   Stuff that everyone here had been talking/warning about, but guess I just had to see it in person.  Now that I'm aware of it, it's pretty comfortable.  
     
    My first attempt at a power-off landing was a little sketchy, too.  I'd planned to make a power-off approach, low pass, and a go-around, but it turned into a pretty hard unplanned water landing.   Learned pretty quickly that under about 65MPH, I don't have enough residual energy for a flare in a dead-stick landing.  
     
    Now I'm into the real horrifying stuff- radio interference problems
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  21. cowlove added a topic in Avidfoxflyers General Hangar   

    Avid Catalina N157AB's first flight out of KRNT, well over 2 years after I first said, "two weeks!"

     
    It went pretty smoothly. For being such an unusual plane (high-drag/low-inertia, off-axis thrust, high CG, full length flaperons, blah, blah) she was pretty honest and discoverable.
    No real problems or OH-**** moments. (that was saved for flight #3)
    I'm glad I ended up doing flight testing out of KRNT- I was going to operate out of a boat launch somewhere else on the lake away from what I thought would be the stress and distraction of controlled airspace. In reality, they've been great and very accommodating.
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  22. cowlove added a topic in Rotax and other engines   

    Fair price for timed-out 582 & Ivoprop IFA?
    Hey- I'm looking at buying a local fellow's timed-out blue head 582, complete with bings, exhaust, c gearbox and Ivo IFA.  Any guess at what a fair price would be?  Not much out there on the internets right now. 
     
    Thanks!
    Jim
     
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  23. cowlove added a topic in Avidfoxflyers General Hangar   

    Avid's published G ratings - working or ultimate load?
    I'd always assumed that all the G ratings specified in Avid's original literature were "working load" ratings similar those specified for certified aircraft, i.e: a 50% safety factor before the ultimate load and failure point. 
     
    However, I stumbled across http://www.challengers101.com/GrossWeight.html, which implies that sometimes experimental designers specify things in terms of ultimate loads.  
     
    Anyone have a feeling if the +4.4/-2.2 figures repeated in all the literature are working or ultimate figures?  
     
    I doubt it will change the way I flight test or fly N157AB at all, but it does slightly affect my comfort level
     
    Sincerely,
    Jim
     
     
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  24. cowlove added a topic in Avidfoxflyers General Hangar   

    Avid Catalina: first Condition Inspection, advice on logbooks?
    After about 18 months of tearing things apart and rabbit-hole projects on the plane, N157AB is (hopefully) ready for her condition inspection.  She had a CI right after I bought her, but this is the first CI I've done that involves work and logbook entries about things I've done.   I have a hand-written journal extensively (and sloppily) detailing the 500 or so hours of work I did, and was going to condense that down into a printed-out insert that I was going to staple or paste into the logbooks. 
     
    Any thoughts on my logbook?   I broke out the two major projects (new flaperons and wing rib repair) into separate write-ups that I gave to my A&P to get his input on the proposed work before I did it.   Do you think it's OK to just make a logbook entry that says basically "Fabricated new flaperons, see attached" and keep those writeups with the logs? 
     
    The work is all scattered over the year, do you think just one date and signature is fine? 
     
     
    My logbook entries I'm going to paste/staple into logbooks.
     
    Separate wing rib repair writeup
     
    Separate writeup about new fiberglass flaperons
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  25. cowlove added a post in a topic Source for flaperon bushings? Or stock material suggestions?   

    I got better at turning down the 7/8" OD bushings, using a rasp and sandpaper rather than a turning tool.   I liked these results better than the milk jug, and am going to go with that.  
     
    I never did find a 1213-xx bearing.  Igus GFM-2021-20 is a metric near-equivalent.  I couldn't find one stocked at any reseller, but Igus will sell direct, albeit with a hefty handling/shipping fee.  I had some coming, but cancelled my order when I decided the turned-down ones were acceptable. 
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