Hurricane Mk103

Discussion in 'The light stuff area' started by pictsidhe, Aug 6, 2018.

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  1. Aug 15, 2018 #81

    WBNH

    WBNH

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    Minor interruption of the 103 part of this thread...

    Maybe it's been mentioned, but it's news to me...youtube just alerted me to a new movie coming out this fall regarding the 303 squadron, titled Hurricane. [My great uncle was flying a Hurricane with the 504 sq, lost 5/14/40 -- Battle of France.] The trailer if it interests anyone: https://www.youtube.com/watch?v=IV5e2HA6XkU

    Sorry for the drift.
     
    Last edited: Aug 15, 2018
  2. Aug 15, 2018 #82

    pictsidhe

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    I think I may, in time, be able to forgive you ;)
    Sounds interesting. 303 was the highest scoring squadron of the Battle of Britain. They flew Hurricanes, not the 'saviour' Spits...
    My Grandad was a warehouse storesman in the Mediterranean in WWII. Invalided out with a 2" shortened leg after his warehouse was bombed. Oh, well, my mother and two aunts wouldn't have been conceived if he hadn't been sent home early...

    Edit, I need to check with Mumsy how short that leg was. He had one hell of a limp.
     
  3. Aug 15, 2018 #83

    radfordc

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    I find it fascinating that you expect to duplicate a Hurricane's behavior in an aircraft that weighs 254 lbs! Fascinating!
     
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  4. Aug 15, 2018 #84

    cluttonfred

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    I agree with radfordc. pictsidhe, spend some time watching YouTube videos of Loehle 5151 Mustang and P-40 "replicas." They sure look like fun in a Walter Mitty way, but they lighter than a J-3 Cub and fly that way. Your "Hurricane Mk103" would have to be *half* that weight and is going to fly like an ultralight not a WWII fighter. Take just the look of a Hurricane and then design the best ultralight you can around that shape and you'll have a safer, more enjoyable plane in my opinion.

     
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  5. Aug 15, 2018 #85

    ScaleBirdsScott

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    Well, if anything, spend time looking at the Hummel Ultracruiser. It's mostly wing! The rest of the plane is rather tiny. And spartan. But, it does seem like fun, for what it is.

    Trying to build something even close to the size of the Loehle replicas is fine but I still don't think it makes sense at anything approaching the part103 regime. The 5151 is 22ft long with a 27ft wingspan... huge compared to a Hummel or a Mini-MAX or similar.
     
  6. Aug 15, 2018 #86

    pictsidhe

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    Don't worry, I have no delusions whatsoever of ever hitting 300+mph with the wings and maybe tail still on. I think I may manage a couple of g sustained turn if I have 40hp. What I really don't want to do is build in a tip stalling tendency. The Hurricane had reasonable manners, I want those manners. I know I won't get the speed and the excitement level is going to be, well, a lot less. Unless, of course, I can screw up the balance so the edges of the envelope turn into a drop into the bowels of spinning hell.

    Plagiarism is easier than blank sheet design. Once I know the angles that the root and tip Hurricane airfoils stall at, I can build a 103 that behaves similarly, if much slower.
    If I was building a FW190, I'd still want to know what airfoils it used, but I'd change things to try and reduce its vicious stall, by getting the inner wing to stall sooner.
     
  7. Aug 15, 2018 #87

    pictsidhe

    pictsidhe

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    A minimax is 25' span. A 2/3 Hurricane is 26'8". With a 12" thick root :). The lazair and VJ24 are 36' span.
     
  8. Aug 15, 2018 #88

    cluttonfred

    cluttonfred

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    One idea that occurs to me when trying to scale down a single-seat fighter is to treat the canopy like a bubble for the pilot's head only and hide the rest of the reclining pilot below the canopy rails and forward all the way to the seeming firewall (actual firewall would be more forward). It works better with something with a fairly rearward cockpit like the Corsair or the Saetta:

    Screenshot 2018-08-15 at 10.38.43 PM.png
     
  9. Aug 16, 2018 #89

    pictsidhe

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    That was plan A. Unfortunately, my eyes would only be 2" above the bottom of the windscreen. I am going to sacrifice scale for a better view with a taller canopy. Which will still only have my head in it...
    To stop it looking too enlarged, I could shift the canopy rails up a bit, too. Canopy opening will probably extend below the plexi part (or I paint some plexi) to give better cockpit access. The full size Hurricanes had in flight adjustable seats. the pilots would open the canopy and jack the seat up for landing. An acme screw arrangement like full size would be very heavy, but an inflatable seat cushion would be way lighter...

    A 103 with the pilot behind the wing is going to be very tricky to get a safe cg on.

    If anyone has a good source of glider seating pics, I am having trouble finding any.
     
  10. Aug 16, 2018 #90

    Tiger Tim

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    Crazy Plan B: do your Hurricane in one of the all-black schemes so some portion of your cockpit side walls can be dark tinted plexi.
    [​IMG]
     
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  11. Aug 16, 2018 #91

    pictsidhe

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    Hmmmm, could work with brown or green tinted plexi too... Filed, for possible future use...
     
  12. Aug 16, 2018 #92

    Tiger Tim

    Tiger Tim

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    I suppose you could even do clear and have it covered in a wrap full of holes, like they do on the rear windows of some wrapped cars.
     
  13. Aug 16, 2018 #93

    pictsidhe

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    Hmmm, how would you do that with paint, clearcoat spots before spraying? Perforated sheet would make a great mask for that. Paint, then sand through the paint to clearcoat.
     
  14. Aug 16, 2018 #94

    pictsidhe

    pictsidhe

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    Or, hot roll the plastic with a holy roller to create raised spots, paint, sand.
     
  15. Aug 16, 2018 #95

    billyvray

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    Any thoughts on a totally unscale warbird - cartoon scale? Fat body little thing would be too cute. This is an RC model.

    fat spit.jpg


    Bill
     
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  16. Aug 16, 2018 #96

    pictsidhe

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    A 3/4 scale fuse width and height would change the cockpit from 'glove' to something I could sneeze in. That may happen. I'd have to go bigger for the cartoon effect, though. That would clearly be a fun sized fighter though.
     
  17. Aug 16, 2018 #97

    cluttonfred

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    Isn't that a Fly Baby? (Ducking as Ron W. throws yet another empty whiskey glass....) ;-)

    Wait a sec, that was Fritz, Ron is from the Northwest, maybe he throws coffee mugs. :p

     
    Last edited: Aug 16, 2018
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  18. Aug 22, 2018 #98

    pictsidhe

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    I've been flitting around a bit on this. I wanted to see if my Briggs engine idea is feasible, so I've been doing way too much TV recently ;) It looks like it will work, with effort. That gives me loads and loads of legroom! also been looking at control surfaces. I may have to tweak things to give enough force at the stick. With the same stick deflection, forces vary with the cube of scale. They also vary with the square of speed. a 2/3 scale Mk103 is only going to have a few % of full size stick forces, which is something I won't want to sneeze at... All the balances can easily go, then it gets a bit tricky. I think that extra reflex on plain differential ailerons may be the way to go.

    Engine specs, revised slightly from 1938:
    Type:
    HTML:
    del
    Rolls Royce Merlin
    HTML:
    /del
    Briggs & Stratton Vanguard V
    HTML:
    s
    1
    HTML:
    /s
    Capacity:
    HTML:
    s
    26
    HTML:
    /s
    .6 litres
    Power
    HTML:
    s
    10
    HTML:
    /s
    40hp
    Weight
    HTML:
    s
    12
    HTML:
    /s
    80lb

    I have some more drawings on the way, including a set of main production wing profile drawings and ordinates. Jackpot!
     
  19. Aug 22, 2018 #99

    pictsidhe

    pictsidhe

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    I've been flitting around a bit on this. I wanted to see if my Briggs engine idea is feasible, so I've been doing way too much TV recently ;) It looks like it will work, with effort. That gives me loads and loads of legroom! also been looking at control surfaces. I may have to tweak things to give enough force at the stick. With the same stick deflection, forces vary with the cube of scale. They also vary with the square of speed. a 2/3 scale Mk103 is only going to have a few % of full size stick forces, which is something I won't want to sneeze at... All the balances can easily go, then it gets a bit tricky. I think that extra reflex on plain differential ailerons may be the way to go.



    I have some more drawings on the way, including a set of main production wing profile drawings and ordinates. Jackpot!
     
  20. Aug 22, 2018 #100

    radfordc

    radfordc

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    The Briggs engine I'm familiar with is way too heavy for any Part 103 airplane. This is the Vanguard engine at 125 lbs and to this you will also need to add a redrive and prop. And you're still getting less than 40 hp. There are many much better options available (Poloni, Hirth, Rotax, etc).

    I have flown many ultralight planes and they all had acceptable stick forces. I don't think this will be a problem.

    I'm still getting the feeling that you don't have a real appreciation how difficult it will be to make the 254 lbs weight limit. I started flying ultralights with a Quicksilver MX and even that was above the legal weight. Every UL that I've owned has been over the legal weight.
     

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