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Thread: Some raven questions

  1. #11

    Some raven questions

    2. The Eclipser has two fibreglass rods in pockets down either side of the trailing edge of the fin to reduce flapping

    - Same as a Sprint then? ;-)

    Not too happy about Kestutis' drilling of the tang to 'shorten' the front wire. It means drilling through the bent section of the tang, which is already slightly weakened. Plus, any loads generated in that front cable will now tend to bend the tang across that new hole. (Was also true of the original hole, but at least that was held flat under the bolt head.)

    I'm not convinced of the need to stop any fin 'flapping', but if you must, I'd be more tempted to tighten the cable 'diamond' by other means. A new shortened cable is obvious, but not allowed in the UK without approval (unlikely). Drilling a new hole in the tang fixed to the cable would be easiest, but you'd need to cut the surplus off the tang to stop the old hole getting in the way. Perhaps an extra washer under the kingpost to keel fixing bolt also springs to mind.

    Dave

  2. #12

    Some raven questions

    one problem with a flapping fin is to get small amounts of wear on the luff lines where they meet the fin at the top. This can happen regardless but is accelerated by the movement of the fin... Something to check at periodically!
    As you move it forward on the hangpoint it has the effect of tightening the front to back lower wires which will pull the keel down. This will tighten the fin up a tad as well. (and doesnt need approval!) you could slow it a bit at the tips to offset the increase in trimspeed.

  3. #13

    Some raven questions

    I should have said that I fly the Hornet rigged version of the Raven. Because the bar is rigged further forward, the side wires (which are the original length) are absolutely taut at all times. I think the new length fore/aft wires are cut slightly tighter too (I know this as, if the hang bracket flips whilst rigging, it nearly takes your finger off).

    The wing winds up with slightly less dihedral (actually, more anhedral) than the standard Raven and, I think, flies better for it.

    Dave

  4. #14
    Senior Member
    Join Date
    Dec 2008
    Location
    Kaunas, Lietuva (Lithuania)
    Posts
    195

    Some raven questions

    [quote=Dave Smith]

    Not too happy about Kestutis' drilling of the tang to 'shorten' the front wire. It means drilling through the bent section of the tang, which is already slightly weakened. Plus, any loads generated in that front cable will now tend to bend the tang across that new hole. (Was also true of the original hole, but at least that was held flat under the bolt head.)

    I'm not happy too. But it was simplest way solving the problem :icon_smile: The "bent" shape does not form a sharp angle but radius (about an inch), so according my judgment hole should not weaken the tang much (on top of that the upper system is not laden much in flight).

    I’m also curious – may be the flapping is a “MUST” for the Raven wing as it produces an additional stabilizing force?

    Any way, thanks Dave for warning :icon_smile:

  5. #15

    Some raven questions

    I agree. Having done it, it's probably going to be fine. But I wouldn't want others to copy.
    Keep a check on it for any sign of cracking from the hole...

    Better yet, do you have access to a Nicopress tool? Or someone who has (boatyard)?. Make up a complete new front wire to the shorter length with new Seasure tangs (for non-UK owners only ;-) ).

    Very best,
    Dave

  6. #16
    Senior Member
    Join Date
    Dec 2008
    Location
    Kaunas, Lietuva (Lithuania)
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    195

    Some raven questions

    Thanks Dave,

    and yes, I have everything I need :icon_rolleyes: ...

    Happy New 2010 :jumpin:

    Dave Smith wrote:
    I agree. Having done it, it's probably going to be fine. But I wouldn't want others to copy.
    Keep a check on it for any sign of cracking from the hole...

    Better yet, do you have access to a Nicopress tool? Or someone who has (boatyard)?. Make up a complete new front wire to the shorter length with new Seasure tangs (for non-UK owners only [IMG]/forums/emoticons/wink.gif[/IMG] ).

    Very best,
    Dave

  7. #17
    Junior Member
    Join Date
    Dec 2006
    Location
    Deenethorpe
    Posts
    27

    Some raven questions

    Hi Guys,
    I have finally purchased a raven. It has taken a long time for one reason or another, but I finally picked her up last Thursday.
    I am now the owner of G-MZME as previously owned by Time Bowles.
    A friend and I had a 870 mile round trip up to Oban, pulling a trailer on both legs. We also suffered a tyre blowout on the trailer at 65mph at 23:30, luckily we had a spare wheel. She is now safe in the hangar.

    I have flown her now, but only for around 30 mins. Initial thoughts are
    1) very light in pitch
    2) you are much higher off the ground than in a quik/quantum, ths lead to rear wheels touching on landing before I wanted
    3) heavier in pitch
    4) quite slow, the asi was reading only 55, however I don't know how accurate this was as I didn't have a gps with me, also there are two foward hangpoints to try.
    5) Didn't seem to like turbulence. It was a pretty calm day, but warm, so quite a few thermals and I thought that the wing got kicked around quite a lot, definitely worse than I was expecting.

    I now have a few issues to sort before I have any chance of flying to Popham.
    Front steering very stiff, I have managed to free this by undoing the pivot bolt and applying grease.
    Engine not that smooth, traced to a wrongly fitted carb diaphram, and on teh other side a hole in the daiphram.
    Hopefully new diaphram will arive today and I can get the engine running sweetly.
    Whilst waiting for the diaphram, I have removed the prop, reset the pitch (one blade was under pitched), applied prop tape and balanced it.
    I also have 2 leaks on the fuel tank, where the feed pipe exits the tank, and where the skirt should attach. I have to send Chris D pictures so that he can advise best way to fix. The good news is that it only leaks when completely full, so won't stop me flying.
    Another issue is the flydat readings for cht and oil temp. When switched on, and before the engine has been run, they indicated 57 58, which is about 40deg higher than it actually was. I'm a bit stumped on this one, why should both readings be 40 above, if it was only one, then I'd think sensor, but when its two readings..... I'll have to have a play with my multimeter. Again this won;t stop me flying

    So, hope to see some of you other ravens about over the coming months.
    Cheers
    Ian Smith
    G-MZME

  8. #18
    not real name 500 Club
    Join Date
    Mar 2009
    Location
    Glen Innes NSW - previously The Banana Stip - aka Stoke International in Kent
    Posts
    847

    Some raven questions

    Hi Ian,

    Welcome to the club ... small and exclusive though it is the members seem freindly.

    On the fuel leaks I'll match you, I too have two on mine. I cannot get a proper seal around the fuel sender, and the self tapping screw for the skirt also leaks - but like you only an issue when full to the top so I tend to leave a little out. The first leak I should be able to fix with a new gasket/o-ring (Chris did note I needed general TLC when he did my last permit inspection) but the skirt screw one is an issue from tank manufacture.

    I think it was assumed the side channels moulded into the tank that mounts to the base tube would be solid after the rotational molding, clearly there is a double skin in that area on mine that is pierced by the self tapper and I guess I could lock tight or silicone seal it but I have not bothered.

    I got the hump with the flydat and its odd readings and did the factory fit of the GX1 instrument to cover all my engine and flight instruments in one, nicely freed up dash space to have radio/transponder/GPS etc. and only needed one change to the senders (oil pressure).

    As for sitting higher yes, and once you stop trying to land 8 inches below the ground (the 'look you have from flying a quantum) I am sure you will find the Eclipser just as nice to land ;-)

    Hope the weather plays nice for the weekend, see you at Popham on the Saturday if it does.

  9. #19

    Some raven questions

    Does the Flydat have a Fahrenheit setting option???
    Surprised you find it affected so badly by turbulence - I believe the Raven has the sweetest response of all. Must have been a seriously rough day?

    Dave

  10. #20
    not real name 500 Club
    Join Date
    Oct 2007
    Location
    Edinburgh
    Posts
    1,285

    Some raven questions

    Ian Smith wrote: Initial thoughts are
    1) very light in pitch
    ...
    3) heavier in pitch
    Hmm. Can you elaborate?

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