napierm

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About napierm

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  1. napierm added a post in a topic Bush gear topic reopened   

    For all users of wide "bush" gear on a KF I know from experience that the rear gear mount is very weak in compression.  The front mount is attached to the seat truss and so is pretty stout.  But the rear one attaches at a point where there is a single tube going across under the seat.
    What this means is that if the gear catches hard this cross tube can fail and the rear part of the gear leg attachment wants to come through the bottom of the seat.  Think of it as a long lever arm and picture where that rear point wants to go....
    If I were designing a wide gear set I would do a Highlander style with the 3 attachments, the rear one with a big diameter tube that attached below the lift strut.  That is a very strong attachment plus it is not under my butt.
    FWIW
     
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  2. napierm added a post in a topic Starting my Homemade Hackman   

    I'm a little late for this thread but I thought I would add my 2 cents.  I flew the Hacman on my 582 and had good success with it.
    The Bing carb works by metering the fuel flow through the various jets from the float bowl to the venturi.  The fuel flows up because of the venturi vacuum (also known as ported vacuum).  This is different from manifold vacuum.  (I got laughed at once for hooking up a vacuum advance to manifold vacuum rather than ported vacuum so I have this concept down pat)  Ported vacuum generally increases with carb airflow.  The Bing 54 slide carbs increase the venturi area with increasing "throttle" so the ported vacuum is more constant than it normally is with butterfly valve carbs.  Also, the Bing 54 carbs do block off the back of the throat at idle so there the ported vacuum all but disappears.  Then the idle circuit behaves normally. (BTW, I had to replace my "55" idle jets with "45" jets to get it to run well at idle.  Otherwise it would load up and quit on final.  Nothing to do with the Hacman, these jets are too rich from the factory.)
    The pressure in the float chamber is vented to the nipple on the side.  So the differential pressure (float to venturi) and the jet sizes are what control fuel flow.  These vents are normally connected into the dual air cleaner so that the float chambers see the same pressure as the intake ports of the carbs.  The Hacman works by slightly lowering this pressure to lean the mixture.  In practical terms hook it up and start with a large orifice from the air cleaner.  Then work down to a smaller one.  You really shouldn't be able (or need to) change the EGTs by more than 200 degrees over the adjustment range.  I don't mind turning the dial quite a bit but most all of the adjustment is in the 1st couple of turns anyway.  As others have said you do wind up needing a larger main jet.  Once tuned up the system works great.  Lets you lean at altitude.  Better yet lets you richen it when you point downhill from a long cross country so you don't get too lean.
    I really have to thank Tom Olenik for explaining how to set up and run the 582.  He had is own business, Olenik Aviation, for a while but found a better job as a "Propulsion Engineer" for a corporation that makes big drones.  I gladly bought all my supplies from him at the time.
    Greensky also sells this system for the Bing 64 CV carbs.  In this system they use the manifold vacuum.  This vacuum source varies a lot with throttle setting and prop loading.  They say in the online instructions to close the valve (full rich) before pulling to idle, otherwise you could shut off the engine.  A better solution would be to take advantage of the Constant Vacuum (CV) available in that venturi.  Looking at the carb I can see that the venturi is ported to the top of the CV chamber.  I'm still looking at that chamber cap to see if there isn't a good way to secure a nipple there on one of the carbs.  The very top has a thin metal cap that looks to be peened in place and bonded with hi-temp epoxy.  It doesn't look strong enough that I would trust it not to fail with anything attached.  The advantage would be a fairly constant vacuum over most RPMs.  At idle (closed butterfly) this vacuum all but disappears so again the idle circuit would behave normally.
    The CV carbs are about 1/2 altitude compensating anyway.  It's only at "high" altitudes (say 7K+ feet cruise) that they could use a bit more leaning.  Not as clear a use case as with the 2-strokes.
    FWIW,
    Mark Napier
     
     
     
     
     
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  3. napierm added a post in a topic repair manual   

    Anyone want to do similar with the 912 overhaul manual?  It's not distributed unless you have taken all their classes *and* are a shop "in network".
    For instance, an older engine should have all the seals replaced.  But there isn't a published procedure for splitting the case and reassembly.  I've done a 582 twice now and was grateful for Tom Olenick talking me through it the 1st time.  Is there a build up of similar tribal knowledge for the 912?
     
     
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  4. napierm added a post in a topic I need a Kitfox 4 wing rib   

    I need to make up a set of KF IV ribs and have one non-flapperon rib to use as a pattern.  I can confirm that the one I have is made from 5mm Finnish plywood.  Can someone confirm for me that the flapperon rib is cut from 6mm plywood?
    Thanks in advance.
     
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  5. napierm added a post in a topic 912 aftermarket ignition   

    When I needed one 4 years ago Lockwood charged me over $1100.  The web page showed less than $800.  The charge whatever the $@!@#$ they want to.
     
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  6. napierm added a post in a topic Starting my Homemade Hackman   

    Yes, exactly the same part.
     
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  7. napierm added a post in a topic What's the proper way to repair this?   

    As you begin your inspection, *don't* cut the fabric.  I've repaired a few places on my III and helped with other fabric repairs.  Your can peel the fabric off.  If it was covered the standard way, peel the tape up from the side enough to show the edge of the top fabric.  Then peel the top fabric off leaving the tape attached.  Preserve all the tapes.  Then peel the side fabric off from around the top tubes.  Hopefully you don't have to take it loose from the bottom too.  If you do have to take the bottom off then try to peel from under the bottom of the sides 1st and *don't* disturb the side or upper tapes: just peel from the inside.  The idea is to leave the finish tapes undisturbed along with that expensive finish.  A thin dull knife helps to separate the fabric from around the tube.  This takes patience but it's well worth doing.
     
    As for the bent tubes, I made a simple tool that has a 1/16' chromoly strap and a half "U" block.  The idea is that the strap goes around the tube and about 1 inch away the U presses against the tube.  The is enough steel on the U block than you can get a cheater bar on it.  Draw a sketch or two and you should get it.  I can post a picture.  Anyway, you can slowly work out the bends.  Unlikely that the tube is buckled.  It can be cold worked a long way.
     
    When the tubes are strait again, the fabric can be glued back on in the reverse order you peeled it off.  The tape gets glued down last.  If done carefully the only line left is the zig-zag seam at the edge of the one tape that you pulled up on one side.  That can be touched up.  If you're real lucky even that may line up.  If you peeled from underneath even that will be hidden and no one will see it.  Once glued back down tight the fabric has some shrink left in it that can be taken up by carefully using a hobby model airplane covering heat gun.
     
    I know this isn't the recommended method but I've seen it work and used it myself.
     
    Good luck,
     
    Mark Napier
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  8. napierm added a post in a topic Man ejected from plane... and no it wasn't a fighter   

    It's more complicated than what was reported in the news.  Very bad day....
     
    http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20130330X85743&key=1
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  9. napierm added a post in a topic Min battery 582   

    I used the Odyssey PC625 battery which weighs 13lbs.  It is way overkill for the 582 but I wanted some reserve for electrical stuff and sure starts, etc.  The PC625 also is one of the cheaper models of this brand.  You could probably use the PC310 which is only 6lbs but I think its too pricey.
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  10. napierm added a post in a topic Ivo prop constant speed   

    What is it in the motors that is breaking? The duty cycle of them is low enough that they should last if well built and matched to the load. The actuator motor in an autopilot will easily last 2000 hours of constant motion and that is the old brushed versions. The new stepper motor versions - I have no idea how long; basically limited by the life of the bearings.

    Sounds like IVO needs to do some re-engineering.
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  11. napierm added a post in a topic Looking for some landing gear part numbers   

    Glad we don't have "the most basic and most widely used type" they sell. Darn'ed near $80 a set.
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  12. napierm added a post in a topic Looking for some landing gear part numbers   

    Bill 8/3/2004 - Has to get one in, will call me back.
    McGuire Bearing 208-342-2281 Ordered 8/9/2004 Steve

    1 2 Hub Shaft Seal 7/8IDx1.575ODx1/4Thick 08152SB 6.08 12.16
    Cross for CR 8763

    Joey,

    I have ordered new seals from these guys, give em a try.

    Mark
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  13. napierm added a post in a topic Interesting day at my house   

    "caused by chemical reactions" , right. Dry ice to gas co2 isn't chemical or dangerous. Called ATF? The world we live in now is too stupid to fathom.

    Now mixed oxy and gas in a Mylar balloon, that will wake the neighbors and maybe even break a window if you're not careful.



    Guess who had a wasted youth?
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  14. napierm added a post in a topic Blown tire   

    Hey C5,

    I thought you had the Kitfox 8" wheels. I run mine tubeless. Bead is so hard to set on those ATV rims the tire is not likely to pop back off.

    Mark
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  15. napierm added a post in a topic HKS 700E performance   


    Here's one:
    http://www.mez.co.uk/mezporting/exhaust_length.html

    There was another one but can't find it now. Wants CC of 1 cylinder, target RPM, and exhaust valve timing.

    Found a picture of Paul's HKS on his trike. He sent me more detailed stuff a while back but I think I've lost it all now along with my last brain cell.

    http://forums.bmaa.org/default.aspx?f=15&m=103195
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