Activity Stream

Activity Stream

  1. TJay added a post in a topic Metal leading edge?   

    Anybody ever try to cover the whole top of the wing with Aluminum? Just wondering if it would fly different.
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  2. EDMO added a post in a topic PRIVATE FORUM - Think Again!   

    Is there room in-between the Climate Change "Believers" and "Non-Believers" for an "Agnostic"?  What does "Computer Spying" have to do with Climate Change anyway - Because Al Gore is responsible for both?   I doubt that he is that important - He just cashed in on both!  Oh Bummer ripped-off the taxpayers with his "Green Energy Solar Panel Company" and Gore and Pelosi each pocketed millions by selling their stocks before it folded.  (Insider Trading)?  EDMO
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  3. chopndrag added a post in a topic Uncoordinated Stall   

    When I was getting my license I had a female cfi and she taught me that you need to keep the wings level , add full power and use the rudder until you are flying again. My dad also always told me that too . I know from experience that when sh!t hits the fan fast you sometimes forget the right thing to do . It sucks to have such an expensive plane get dinged up but he walked away from what could've been way worse.
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  4. dholly added a post in a topic Metal leading edge?   

    HH wing here.
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  5. dholly added a post in a topic Aerobat   

    Here's a copy of the Avid Aerobatic Manual: 
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  6. dholly added a post in a topic fwf value?   

    FYI... here's a copy of the Craigslist ad I posted for a 582ul FWF a few years back. Sold very quick, buyer traveled from 2 states away.
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  7. 1avidflyer added a post in a topic Metal leading edge?   

    It was used on both of my MK IV heavy hauler wings.  JImChuk
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  8. lv2plyguitar added a post in a topic Uncoordinated Stall   

    I would not focus so much on the donations.  The technical information helped me more than anything.  If the people in Alaska want to help him fix his plane more power to them.  I would be hesitate however to ask for donations if I crashed my plane.  :-)
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  9. EDMO added a post in a topic Where to buy split oilite bronze bushings   

    Thanks Leni - Got it - Had been to that page but didn't see Rulon.   found them this time.  EDMO
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  10. jared payne added a topic in Avid Model IV   

    Metal leading edge?
    Going over the plane and wings last night I see in the manual a leading edge aluminum sheet approx. 1 ft by full length. Is this only for speed wing? I have heavy hauler wings 
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  11. Mohawk Aero added a post in a topic Yamaha RX1 Engines   

    Running a RK400 clutch on a Rotax C (RXC) gearbox requires inspection and/or wear maintenance such that every 75 hours (like about once a year for most weekend warriors) the mechanic must disassemble the RXC by first draining the oil then splitting the case halves, and then pulling the back half of the PSRU off of the engine mount or adapter. There are other solutions to this type of power plant conversion than this time-consuming, vexing and messy adaptation.  
    First:  Why use a clutch at all?  Easy starting.  Prevent cracked welds.  Some YG3 and YG4 conversions with certain prop combos will absolutely not start w/o one.  
    What else is there?  Mohawk's GT4, a maintenance-free roller ramp clutch that is a little bit smaller and exactly 1/2 the weight of an RK400.  (RK400 weighs in at 7 pounds, the GT4 clutches weigh 3.5 pounds.)  
    Next:  Why use an RXC gearbox?  I've worked with them.  We all know of Steve Henry, and he uses it - right?  Well, here's the thing - He uses them for one reason, and one reason only:  It is shorter than other mass-produced gearboxes that are readily available, and thus allows it to fit under the cowl of his Highlander w/o mods.  
    That's it.  There is no other reason.
    The first time I split one open and looked inside I walked away and looked to other solutions w/o a second thought. That was 8 years ago.  Since then I have read on other forums and heard first-person accounts of RXC bearings failing after as little as 12 hours, and others at 300 to 400 hours on high HP applications.  These horror stories are kept under tight wraps for the most part, no one wants you to know how fragile the RXC can be.  
    Guys, I don't know what you "know" or don't, I don't know what you've been told, but there are other options available.  First in 2012 came the universal Mohawk YG4 adapter which fits any PSRU ever built.  That super light-weight adapter has been flawless from day one - tested and flown for at least 500 hrs with many different types of PSRUs, including an amazingly smooth, robust, versatile and light weight Hy-Vo chain drive, the Mohawk Silent Drive which includes a prop-strike protection clutch.   
    Next, a couple of years later, Teal called and inquired about my adapter, but decided he didn't want a "stacked" adapter, instead he wanted something to replace the crankcase cover and went on to fabricate and sell (much to my chagrine) his own adapter, limited to the RXC and YG4 (RX1).  I ahve no idea why he required an engine cover replacement.  If we were dealing with my old 500 HP 500 Ft Lbs torque Porsche GT1 race car I guess I could see the point, but in my extensive motorcraft experience and knowledge of engineering practices I decided - quite rightly - that adapter design was more than adequate. The proof is in the pudding: the design has been a perfect, a flawless performer right out of the gate and from then on for well over 500 hours to date and counting.  Both types of adapters use exactly the same mounting points,  removing the engine cover is pointless with only 150 HP and 90  FPT involved.  The way my adapter is built, fitted and attached it simply cannot move under these forces, and any difference in performance of the two designs for this application has been well proven to be a moot point.     
    Regardless, there is now a third option which, like Teal's YG4-to-RXC adapter, replaces the crankcase cover.  Unlike Teal's model which is designed around the diminutive RXC, this one fits a heavy-duty SPG or Mohawk SP gearbox, rated at 9000 kgm (compare to RXC at just 2/3 that, 6000 kgm).  I do not fabricate these adapters.  I do, however, sell all three - Mohawk universal GTA, The latest uni-cover adapter for the Mohawk SP and the Air Trikes SPG, and the Sky Trax uni-cover adapter for the RXC.  They all sell for $1500.00.  But, tell you what:  I am in a generous mood, and will sell you one of these new uni-cover adapters for just $1195 for a limited time.  Again, that is for a limited time, only, so if you see this post next month and want this deal, I doubt I will still be feeling so generous.  
    This third adapter is for use with a special Mohawk SP gearbox (MSP, which is the same as the Air Trikes' SPG version but built to different specs to accommodate a shorter installation and clutch of your choice).  Comparing to an RXC:  The shafts are much larger diameter, the gears are much wider, and the bearings are 50% larger.  All of this means more weight, of course, and the proof is in that the MSP comes in around 18 pounds compared to the little RXC which weighs  around 14.5 lbs.  
    But connect the RXC to a RK400 clutch and you get 14.5 = 7 = 21.5 LBs, whereas the Mohawk SP with GT4 weighs 18 + 3.5 = 21.5 LBs.  It's a wash. 
    You don't have to "settle" for the high-maintenance RK400 nor do you have to "settle" for the RXC which was spec designed to a 90 HP Rotax 582 or 617 engine.  Want numbers?  (Again) The RXC is rated at 6000 KGM, the MSP (and SPG)  is rated at 9000 KGM.  
    I have been building YG4 and YG4i (Apex) adapters for many PSRUs, including RXC, Arrow, SPG, Mohawk SP, and my own Hy-Vo Silent Drive since 2011 - several years longer than anyone else - and you will not find anyone, anywhere, who has built YG4 adapters for more than one, single type of PSRU - let alone five very different types, for both the 140 HP YG4 and the 150 HP YG4i (Apex).  
    Did you catch that last line?  You don't have to "settle" for a carb 140 HP YG4.  The 150 HP YG4i Apex gearbox and adapter conversion kit is here - and has been here since January 2017.    
    Mohawk Aero is the only source for the YG4i - Yamaha Genesis 4 (Apex) 150 HP fuel injected motor aircraft conversion kit.  This isn't some dream, this isn't some prototype to be built somewhere down the road in the future.  The future is now, and it is here.  
    Personally, I have found the Hy-Vo Silent chain drive to be far smoother, lighter, quieter, and efficient than any gearbox I have ever tried regardless of brand, and I've run a bunch of them.  They don't compare to the Hy-Vo silent chain, and the big difference is most notable in flight with this type PSRU being far smoother than any gearbox could ever hope to be.  As goes efficiency, bear in mind that with every helical gear & shaft you lose 1-2% power through heat generated by the axial loads produced against the bearings and housing by the angular-cut gears pushing them sideways.  For a two-gear set that is 3-6 HP on a 140-150 HP engine.  For a three-gear set, that works out to 4.5 - 7.5 HP lost (this can be determined with an infra red heat sensor, converting the PSRU heat measured to HP converted/lost), not to mention added, weight, noise and vibration transferred throughout the power plant and airframe. 
    For more info and help with YG4 and YG4i conversions, using RXC, SPG, MSP, Arrow, & Silent Drive PSRU applications, or any of another type you come up with on your own, email Greg at
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  12. akflyer added a post in a topic Where to buy split oilite bronze bushings   

     highlight the link then right click it and it should give you an option to open it.  Took me right to the page.
    try this link for the bushings
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  13. akflyer added a post in a topic Airdale's Bush Gear   

    I used a 10" vice.  I have also done it with a pipe clamp but you should really use 2 of them and its sketchy at best   I need to come up with a way to change these out without risking your life with flying springs.
    Thinking maybe 2 slotted plates with all thread on each side to slip over the collars and then use the all thread to compress the spring.  Should be a pretty easy tool to make.

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  14. nlappos added a post in a topic PRIVATE FORUM - Think Again!   

    Yep, name calling is the right way to prove your point! Any time you want to match credentials, let me know.
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  15. Mohawk Aero added a post in a topic Yamaha RX1 Engines   

    The guts of the YG4 is heritage legacy R1 motorcycle which turns in excess of 15,000 RPMs.  Connecting rods, valves, pistons, wrist pins, all the goodies.  The YG4 (short for the true name of this motor, Yamaha Genesis 4 - RX1 is a sled and no one calls a Mustang engine a Mustang...maybe a 351 or something) has cams that are ground to peak out at 10,250 engine RPM (ERPM), so that with the internal spur gear @ 1.19:1 the final countershaft RPM, or shaft RPM (SRPM) matches the YG3 Nytro speeds and the same CVT clutching can be use on both sleds.  These engines put out a good, honest 140 HP starting at 9750 ERPM, peak out at 143 HP at 10,250, then it starts to drop off and after 10,700 you're really wasting your gas.  
    Don't worry about redline, there is no such thing on the YG4.  The cams won't ever let you get that high with a prop attached.  I suppose if you took off your prop or your RK400 clutch goes south you could free spin the engine up past 17,000 and hit a valve... 
    There is no need for a pre-oiler pump.  The only time time this engine will start w/o choking is when they have recently been run.  I can start mine up to three days after the last flight w/o choke, but most people must use the choke the first start the very next day.  I also use an electric fuel pump, this way I can prime the carbs before hitting the ignition switch.  The Yamaha pulse pumps make great back up pumps, and a single one (they run in tandem on the sled) will provide enough fuel for all manner of flying except full throttle climb.  
    To oil-prime the engine before starting after a long spell of not flying, or in very cold weather (an engine's worst enemy is extreme cold starts), I do not hit the fuel pump switch, and leave the choke open.  I crank the engine for 15-20 seconds during which it never fires, and is plenty of time to run the oil throughout the motor.  Then flip on the fuel pump, choke it and fire her up and away she goes.  
    Being a true snowmobile engine, not a motorcycle engine, the YG4 operates at all manner of extreme angles and conditions - except inverted.  Those cylindrical oil reservoirs I keep seeing on conversions here are pretty, but how well are they baffled inside?  The stock RX1 oil tank is probably much better.  It has a very complicated system of baffles to keep oil where it is supposed to be in all angles of attack.
    To be serious about power, especially in the mid range, converter mechanics really need to figure out a way to work your engine frames around the intake airbox, not the other way around.  When you scrap your YG4 silencer you are guaranteed to lose 5-10 HP across the power band.  One big mistake I see here when fabricating your own airbox: the oil breather hose must be placed in such a manner that the closest carb cannot suck from it, or else that cylinder will be choking on oil and lose power and you will have different output across all 4 cylinders - an unbalanced engine.  Take a look at the inside of a YG4 silencer, and first understand why it is designed like it is with the oil tube venting FAR away from the #4 carb, and where all 4 carbs will pull from the vent evenly.  
    To make a point:  One day I took just the plastic shelf out of a stock YG4 silencer and ran a quick test.  We lost 500 RPMs!  I pulled the foam air filter out and lost another 500 RPMs.  Removed the silencer altogether and the YG4 wouldn't top 5800 RPM.  In other words, the engine is perfectly tuned to the whole system, and changing anything is a step backwards.   
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  16. EDMO added a post in a topic Yamaha RX-1 Engine mount for avids   

    I think one guy asked $1500 for a new one.  EDMO
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  17. EDMO added a post in a topic Airdale's Bush Gear   

    You probably wont find a zip-tie that will hold the pressure - spring compressor is threaded rod or rods with hooks or bars on each end - need one for each side of spring.  You can probably make them.  Be careful.  EDMO
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  18. jared payne added a post in a topic fwf value?   

    Any offers?
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  19. jared payne added a post in a topic Double brakes   

    Will try to post pictures tomorrow, thanks
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  20. jared payne added a post in a topic Yamaha RX1 Engines   

    How much for a mount?
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  21. jared payne added a post in a topic Yamaha RX-1 Engine mount for avids   

    How much for a mount?
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  22. 1avidflyer added a post in a topic motor mount?   

    Leni is right, Kitfox has 5 mount points. (from top of firewall down)   2 on top, 2 in the middle, and 1 at the bottom.  Avid has 6, 2 at the top, and 4 across the middle of the firewall.   Also, if I remember right, the bottom mount on the Kitfox is 1/4" further out or in then the others.  Also, unless you have the streached Avid fuselage, you will have serious issues with the heavy weight of the Subaru out front where a much lighter engine was originally figured to be.  Then you will have to put a bunch of weight in the tail to get the W&B to work out.  It will end up being a two place aircraft if one is a small kid... :-)  And it you did use a Subaru on the Avid, I believe you are supposed to put an additional mounting point down at the bottom of the fire wall for the motor mount.  Don't you have a nice light 582 for that plane?  If you really want the Subaru engine, I have one I will sell you with an NSI gearbox on it.  Even has a Kitfox 4 mount bolted to it.... JImChuk
    PS  sorry if I got carried away with my answer.  The internet was down all day, and I'm just getting back on line............
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  23. chopndrag added a post in a topic Uncoordinated Stall   

    Sure do . I'm just saying we all take calculated risks with our planes every time we go up . He new what he was possibly getting into when he went into the contest and yeah it sucks to ding a plane or anything even with insurance . I totalled a car and ended up in CICU for 7 days I had to still fork out cash from my own pocket to get another car so I could get back to work and support my family. I just see crashes in a contest form different because you are choosing to do it and have to deal with the consequences. More power to him of he can get the donations .
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  24. Fly-n-Low added a post in a topic Airdale's Bush Gear   

    And the elongated slot. Everything has been deburred and polished, painted, etc. I'll have to repost the photos of when I started this since photobucket crapped out.
    Thanks for the input, guys!!!

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  25. Fly-n-Low added a post in a topic Airdale's Bush Gear   


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