Willja67

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About Willja67

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Willja67's Activity

  1. Willja67 added a post in a topic Repairs & Mods: custom cowl, new gear,etc   

    Well gentlemen those are the first 2 out of 4 plies. It only took me 6.5 hrs from when i started getting the epoxy out till calling it a night. As cold as my garage is i doubt it'll cure anytime soon. The plan is to finish the last 2 plies by Monday evening, then tent it.
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  2. Willja67 added a post in a topic Getting close for an engine choice   

    Probably more of these engines on the other side of the pond but this is what i want to do with my -1
    http://www.aircraftgraphix.com/bmw conversion.htm
     
     
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  3. Willja67 added a post in a topic Operation Cannibal Fox   

    ya know just thinking the drag of the wings might not be a liability. Drag increases as speed increases but the distance between the 2 lines is only 3/4 of a mile so for maybe the first 1/3 of that you're not going fast enough for the drag difference to matter and the last 3rd of it you're trying to slow down to land in the shortest distance possible so now those draggy wings actually benefit you? Yeah sure Draco runs away from everyone at the start and can even slow down and stop pretty good with the reverse thrust but you'll notice the distance is greater and most guys made up some time on him by landing shorter and getting turned around in less space. 
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  4. Willja67 added a post in a topic Operation Cannibal Fox   

    Yeah I was wondering about that undercambered airfoil.
    So let's break it down so far:
    Say 7-8k for the engine and prop (just guessing), $4500 for the covering materials (just got a quote last week) say 2k for all the carbon and vacuum bagging materials ( my labor is not counted). I'm putting aftermarket gear on so another grand there, and say another 4k just to round it off  for the mod 4 wings and other goodies with a base price $16,000 plane. So all told about 37k. So we come in less than what he spent on the engine. And it's still iffy. But fun to think about. 
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  5. Willja67 added a topic in Kitfox I   

    Operation Cannibal Fox
    I'm guessing most of you are familiar with Trent Palmer and his kitfox, which he just installed a turbocharged 141 hp Rotax 915 in. He's dubbed it " cubkiller" since the goal was to outperform the carbon cubs at the Stol Drags at the High Sierra Flyin. Here's his video from the flyin: https://youtu.be/3KS9NkpXShg
    So "Operation Cannibal Fox" is to beat Trent Palmer and his "Cub Killer" in a Kitfox 1 at the Stol drags.
    Right now it's mostly a mental exercise because i lack the funds to do it but i want your input on what it would take. Reason for this is even though "cubkiller" is supposed to be the poor man's way to compete with a 300k carbon cub 40k for a 915 doesn't feel very poor to me. 
     
    Here are my thoughts and the mods i would make to do it. 
    1. Cover in Oratex 600UL for the lightest weight covering possible. 
    2. Carbon fiber vacuum infused cowl and anything else to shave weight 
    3. Install BMW R100 turbocharged engine. 
    4. As many streamlined struts and fairings as possible. 
     
    The biggest one on the list is the BMW R100 turbocharged engine for obvious reasons. It seems to be a proven fact you can get 80 reliable NA horses out of a R100 and i was reading last night about how 100 turboed horses is pretty doable without major mods to the engine and if you want to go for 120 then you have to go with lighter pistons etc and you still might have a hand grenade. But let's just run the numbers on the 100 hp turbo since its the cheapest simplest alternative. 
    My bird weighs in at 468 empty. Let's just say i shed the fat on the airframe and the engine and turbo bring it in at the same weight.  With just me and fuel for the race that's 732 lbs with 100 hp that's a power to weight ratio of 7.3. If I can shed the 35 lbs extra I'm packing even better but we'll plan like that's not going to happen.   
     
    Freedom fox weighs in empty around 930lbs and I'm guessing Trent weighs in about 160 plus 40 lbs of fuel with 141 hp on tap yields a power to weight ratio of about 8.0 lbs/hp. So we've got him on power to weight barely, but he's got a Fadec controlled constant speed prop and mixture control which is probably a huge maybe insurmountable advantage. 
     
    So what do you guys think? Is it doable? What would it take to beat him doing it as  cheap at possible?
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  6. Willja67 added a post in a topic Repairs & Mods: custom cowl, new gear,etc   

    It's commencing! Here's the first piece of fiberglass cut for the cowling. 3 more similarly sized large pieces, 4 medium sized pieces, and a few small ones. Advice given to me by a cozy builder in my chapter was never touch it without gloves as the oil in your hands will keep the epoxy from adhering.  I'm also going to weigh each piece of fabric and mix only that much epoxy by weight for it and wet it out on a piece of plastic then drape another piece of plastic over that and squeegee the epoxy out to the edges that way the fabric holds its shape enroute to the cowling then peel the back piece of plastic off and drape it in place.   I'll link to s video soon showing the technique if that was hard to understand. 
    Doing wet layups about the best fiber to resin ratio you can get is 50/50 by weight hence the measuring of the epoxy and fabric. Ive got all kinds of dreams for this plane. Eventually i want to build a carbon fiber vacuum infused cowl for it. If it's anything like the weight saving trent palmer got doing his that's 5lbs more useful load and less nose heavy as well. 
     
    Trent Palmer Cub killer video

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  7. Willja67 added a post in a topic Repairs & Mods: custom cowl, new gear,etc   

    I've got some aeropoxy I'm planning on using. I had thought of a tent and small heater. But maybe i'll consider that more seriously. Especially if my gear gets here soon and i can take the plane to get the gear brackets welded on the will be renewed emphasis on getting the cowling cured and off the plane. I don't want to accidentally damage it on a 120 mile round trip.  
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  8. Willja67 added a post in a topic Avid MK4 braking effect   

    I assume the KF1 pedals are the better design since those are the ones you're using?
    I had no idea Matco was in SLC. that's just on the other side of the mountain from me. 
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  9. Willja67 added a post in a topic Repairs & Mods: custom cowl, new gear,etc   

    Working on the layout for the fiberglass. Right now the plan is 4 plies of Rutan 8 oz BID 38" wide fiberglass over the whole cowl. All plies with be oriented + & - 45 deg from the longitudinal axis of the aircraft. The black lines in the pic are the 45 deg marks.  I think ive got the basic layout firmed up just needed to figure out all the little pieces. The goal is to have it layed up on Saturday.  It's only going to getup to 50 deg so itll take awhile to cure but working alone that's a good thing.  Also hope it'll keep 4 plies plus the overlaps from exotherming on me. 

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  10. Willja67 added a post in a topic Avid MK4 braking effect   

    Brake pedal geometry came up on another forum and they linked here: ultralight news
    There are diagrams from Matco on the proper geometry for brake installations which I've attached below. Hopefully someone finds them useful and they haven't already been posted 20 times on this forum.





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  11. Willja67 added a post in a topic Repairs & Mods: custom cowl, new gear,etc   

    That's the plan exactly.
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  12. Willja67 added a post in a topic Repairs & Mods: custom cowl, new gear,etc   

    All taped off and ready for serious prep for fiberglass!


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  13. Willja67 added a post in a topic Repairs & Mods: custom cowl, new gear,etc   

    So far I don't think I've had any truly original ideas, but if it helps someone else seeing my missteps I'm happy to help.
     
    I will be jealous of your 140 ponies though. Its not in the budget for awhile but if I could put a Bmw R100 in and have 15 more 4 stroke horsies pulling my chariot I would jump on the chance. Obviously I'd love 140 but the airframe won't handle it.
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  14. Willja67 added a post in a topic Repairs & Mods: custom cowl, new gear,etc   

    Just saw this video last night and it got the wheels turning.  We all know the KF1 has neutral yaw stability due to the small vertical tail.  At 6:52 in the video you can see some blue plates he had mounted on the h-stab. I know that float planes often have those added to give more stability due to the destabilizing influence of the floats. Seems to me like it would be a easy way to add some stability without major modification and acting as an endplate might even add some elevator authority. 
     
    So good idea or had?
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  15. Willja67 added a post in a topic Repairs & Mods: custom cowl, new gear,etc   

    No problem easy to misunderstand.  Don't worry I'm not thin skinned about stuff like this and didn't take it as criticism in any case.
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