FredStork

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Everything posted by FredStork

  1. FredStork added a post in a topic VHF Antenna   

    Thanks Chris!
    Yes, they charge full price like for anything that goes on an airplane... I payed ~50USD but if you shop around you can even get it for 65...
    But it works well and is very easy to install. Appears solid.
    Fred
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  2. FredStork added a post in a topic VHF Antenna   

    Hi Chris,
    I'm using an un-grounded dipole antenna, placed on top just behind the turtle deck, and my biggest problem is that I feel like picking up communications from half of France when flying...  Can you explain the coupling issue you mention? The blind spots you are talking about are those for transmission mainly? 
    This is the kind I have, no ground plane required - but maybe we are not talking about the same kind of antennas...
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  3. FredStork added a post in a topic Model C ?   

    Hi Turbo!
    Nice to hear feedback on the films - you can only guess how much I enjoy doing them... Not sure if your message is a question or a "now I know" but I assume the latter and that you have seen the blog http://avidsimonini.blogspot.fr as well about my Simonini Victor 2. Interesting evolution is that Simonini no longer sell the model I have, i.e the one with "only" 92 hp, the entry level is now 100 hp for the weight and cost of a 582 but with the consumption of a 80hp 912... For my longer trips the 20 kg difference is really useful so I can bring all my stuff - and 2 stroke oil for the entire journey (joke on me...)
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  4. FredStork added a post in a topic Who’s experimented with spinners?   

    In terms of drag the difference should not be noticeable but, as already mentionned, do keep an eye on your water temperature as the spinner (can) have a significant impact on the airflow to your radiators...   
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  5. FredStork added a post in a topic Engine Failure yesterday   

    C5Engineer,
    it sounds like you have separate arrivals to the header tank from each of the wing tanks (i.e. the 2 wing tanks are not joint by a T prior to the header tank). If this is correct the noticed behavior is expected. The air in the header tank, with "no where to go" (no vent open and nothing being drained from the header tank) will block the arrival of fuel. The diameter of the fuel lines is too small to let air of any significance trickle back to the tank against the fuel. When you open the valve to the other tank the air will escape through that tank. Once the header tank is full fuel will flow from tank 1 to tank 2 until they reach the same (vertical) fuel level. With identical tanks, and the plane level, they will end up with the same volume.
    If you open the vent on the header tank you can fill it up without opening the second wing tank valve. Either "always open" at a point higher than highest point of your wing tank or open on demand.
    Jim,
    it is not clear if you only have a T between the 2 tanks or if you have a T and 2 valves so you can select what tank to use. If the connection between the 2 tanks is always open fuel will flow between the tanks until they are at the same level (communicating vessels). This is normally not a problem and the advantage is that there are no valves to be set in the wrong positions. But if gives less choice.
    Going back to the start of this string...  if you lose a fuel cap and have communicating wing tanks both tanks could be emptied through the lost cap with little or no fuel reaching the header tank at all (particularly with an open vent...).
    If fuel flow (significantly) faster from one tank than the other (partially clogged fuel lime...), that tank could get drained before the other - ending up with the fast flowing tank working as a vent where air can get sucked into the header tank, rather than fuel, by the pump as discussed in the string. 
    Also, while everyone loves flying most of the time we fly alone, and while we spend a lot of time flying for most of our flights the volume of one wing tank is sufficient. Our planes are light and you can feel the difference between empty and full tanks. Piloting from the left seat the fuel will be a counter weight if you use the right wing tank (single tanks are by default on the right side for this reason). We don't always know if there is ethanol in the fuel and what our tanks think about it, saving one tank from permanent exposure and only use it for long flights might pay back one day...  Same goes for any contamination of one tank, you can use the other. It is also easier to read  the fuel level when using only one tank. Gravity flow will benefit from one tank as the difference between tank fuel level and the outlet will be greater.
    But none of this actually matter as we always fly with the knowledge that the engine can stop at any time and we therefore always know ahead where to land. Slow and light we glide to safety, fold our wings and have a friend pick us up with a trailer... Been there, done that... 
     
     
         
     
     
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  6. FredStork added a post in a topic Engine Failure yesterday   

    You probably have a point there. I even found one explicitly saying not to be used with flammable or explosive liquids... and no one  saying permanent immersion in fuel... I'll keep digging - but will probably end up with the expensive version as usual... Thanks for the link!  
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  7. FredStork added a post in a topic Engine Failure yesterday   

    Thanks! 
    I like the inline version - but why did someone tell them this is used by people that are so rich they have their own aircrafts? I find the standard version for 1/4 of the cost on other sites but unfortunately not the inline version... 
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  8. FredStork added a post in a topic Engine Failure yesterday   

    Hi FlyWise,
    please tell us more about the infra red fuel level detector... like a link to wherever you got it from...
    I have found that the system I have, an inclosed breaker triggered by a tube shaped magnet in somekind of floating plastic, tend to sometimes get stuck in the low position. 
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  9. FredStork added a post in a topic Engine Failure yesterday   

    James,
    there are, as you can read in this string, 2 schools... "Always open vent" or "Open vent only to vent out the excess air, then close it", pros and cons (based on sometimes conflicting theories) has been discussed at length.
    I suggest you read all the mails (i.e. not only my mails and theory - that might be in minority...) . The way I see it is that an open vent is is a way for air not only to escape (that is what we want) but also to enter (and we do not want that). The comment from Gfry is also correct, fuel can get succeed out through the vent line (this is normally easy to detect as your canopy get white and crack almost instantly...)...
    And I do have some thoughts about "both tanks to a tee"... 
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  10. FredStork added a post in a topic Avid 1581 is getting close   

    Beautifu! 2 questions, did you find a usb converter that don't mess up your radio with static, if so tell us about it... The landing gear, is that cub like bungee suspensions under the neat covers?
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  11. FredStork added a post in a topic Shock Cord /Bungee cord   

    Her is another post: (and I can confirm the right chock cord is still in stock a Aircraft Spruce in Eu... By the foot)

     
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  12. FredStork added a post in a topic Better Avid Gear   

    An idea I've had for a while is if the traditional Avid bungee landing gear could be improved without being replaced. I know many pilots really like the wider gear. I'm sure it is nice but I don't mind the narrow gear (and it fit very nicely on the trailer...). What I don't like is the un-damped bungees. The harder you land the higher you jump... 
    What about "just" installing some kind on dampers?  Has anyone already tried this or had the same idea?
     
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  13. FredStork added a topic in Avidfoxflyers General Hangar   

    ANR Hedset - is it worth it?
    Doing a poll for ANR Headsets. They cost a fortune and are sometimes not that efficient with 2 strokes. If you have one, please share your feedback. 
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  14. FredStork added a post in a topic Guess my weight contest   

    573
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  15. FredStork added a post in a topic CONTRIBUTIONS TO KEEP SITE GOING   

    Is the emainl to akflyer in the Feb 9th 2014 post (in this string) still valid for paypaling? 
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  16. FredStork added a post in a topic Luga / Kool / "NR" Propellers   

    Thanks for the update - I was just about to ask.... 
    you mention 95 hp, what engine do you have? I’m currently using short 3 blade warp drive that worked well mith my old and tired 532 but don’t give what I expect from my 92hp Simonini.
    please keep posting your impressions and kool experience
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  17. FredStork added a post in a topic Super STOL XL build   

    2 more "wish I had known before" oratex tips...
    Using plain masking tape the white/light-yellow kind is a good idea. Do NOT use blue masking tape in combination with the glue as it will stain. Luckily that was on the botton of the fuselage and rather limited...
    The pre glued oratex edge tape is good but not excellent. You should apply glue also on the other surface and this makes things complicated when using pinked edge tape. Pinked looks really nice but you will either end up with glue bleeding between the triangles or with flapping triangles, I have seen it on my own plane and on other's (so it is not just me...). Straight edge tape will obviously help. By generoulsy applyning glue on scrap before cutting it you can easily make your own edge tape.
    The advantage of the pre glued edge tape is that is softer and more extensible and there fore might be better for particulerly difficult curves like the tail-fin to fuselage negative bend... 
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  18. FredStork added a post in a topic Super STOL XL build   

    Yes, I can confirm that the glue turns ligth yellow after polymerization (it might take some time). Once the glue has been heat activated it can only be mechanically removed, meaning that any glue bleeds might need to be painted. This is not a big problem as long as you take some care when applying the glue. On Cub Yellow it should be invisible, hardly visibile on most colors, worst is probably white... As you will need a small tin of paint in your chosen color anyway it is realy not a problem. Knowing it in advance (as once applied and dried the glue is transparent/invisible) will help (would have helped...)
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  19. FredStork added a post in a topic Luga / Kool / "NR" Propellers   

    Thanks for the followup, appreciate that! 
    For the incomprehenisbile  relation between prop engaving and actual prop diameter I guess the solution is some back and forth with Roman before placing the order.
    Good luck and keep us updated!
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  20. FredStork added a post in a topic Luga / Kool / "NR" Propellers   

    Lost in translation...
    Roman wrote to me : "SL106-1750mm(3-blades) propeller. The diameter is 1770 mm (with a hub with mounting slots at 101.6 mm)",
    and now you say "blade it says 1770, I ordered 1750 and it measures exactly 175 cm / 69in"... 
    Very confusing.... anyway, we are keen to here you feedback on this magnificent prop, it looks great! 
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  21. FredStork added a post in a topic fiber tank sealing   

    A long article so I'll give you the short version: It is a pain in the butt, close to 40 hours of unpleasant work and if it was to do again he would buy a new tank. Understanding it will not last forever.
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  22. FredStork added a post in a topic Engine Failure yesterday   

    WyPaul,
    don't worry, I will not try to convince you...
    The Mikuni pumps are indicated for 3-5 psi, (5 psi being 1/3 atmosphere). I don't know the spec for the actual pump used but 5 psi is probably a good guess. Emptying the header tank without pulling fuel from the main tank would mean creating a perfect vaccum if we assume the header tank was close to full from the beginning, with 1/3 atmosphere (and that is on the pushing side..) this is obvioulsy not possible. The header tank would have had to be 2/3 full of air to start with to appear empty by 1/3 atmosphere. 
    Gfry kindly tested for us and we know that his fuel pump was stronger than the venturi generated negative pressure in the tank... but we don't know by how much. It doesn't have to be very strong to pull/suck the fuel back through a narrow line with a difference less than 1 meter between lowest an highest point once the pump is turned off.
    Would having both wing tanks communicate help? Maybe but not sure, there would be more fule to suck back to the non caped tank but without knowing the actual negative pressure it is impossible to say. It sounds like the flow was reversed very rapidly, this indicating that the negative pressure was more than symbolic... 
     
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  23. FredStork added a post in a topic Engine Failure yesterday   

    It has been a good discussion.
    I just have a last comment in regards to "air lock" as I think it is important to understand this - it can be useful in other situations.
    In a system with a main tank feeding into a header tank through a line that is as narrow as those we normally use (i.e. so narrow that the surface tension will prevent air from trickle up through the fuel line) you would get an air lock if the headertank had enough air in it. See, I agree with you!  But this is true ONLY as long as we are not consuming any fuel from the header tank. ...but as we are more concerned about what happens when we need the fule than when we don't.... 
    As soon as you let fuel out of the header tank it will be replaced with the same amount of fuel from the main tank as the fuel gone out has to be replaced with "something" and as the only thing that have access to the header tank is fuel from the main tank that is what it will be (sometimes refered to as "nature hates emptiness"). The amount of air will stay the same but is not preventing the passage.
    It will be more like an "automatic air valve" that opens when you consume fuel from the header tank and automatically closes when you turn off the engine. It is ttransparent to the flow. You will not know the air is there unless you can see it. 
    With a high wing and wing tanks setup, and therefore a gravity feed configuration, you can use both configurations open or closed header vent. In the ideal world (see earlier posts) both will work just fine.
     
    But it has been fun - we need another "Avid Flyer Murder Mystery" to resolve!
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  24. FredStork added a post in a topic Merry Christmas!   

    Happy holidays!
    I know most of you have alread seen how I save Father Christmas with my Avid Flyer... you can always share it with someone who has not seen it...
    Fred
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  25. FredStork added a post in a topic Engine Failure yesterday   

    Hi Yamma-Fox!

    It is good to be challenged – either I’m wrong or didn’t express myself clearly.

    It is often easier to resolve a problem by using extremes – like “empty”, “completely clogged” etc.  but from that you then have to go back a step or two. Maybe I only did that in my mind.

    If you are using an old fiberglass tank you should expect there to be “things” floating around that you prefer not to have there… One day those “things” might end up in the wrong place and while not completely blocking the flow it will reduce the flow.

    If the remaining (reduced) flow is slower than the your actual fuel consumption you will, with the header tank vent closed, get help from the pump to increase the flow. Hopefully enough to prevent starvation.

    But if the header tank vent is open and the fuel flow is slower than your actual fuel consumption the level in the header tank will slowly decrease and the header tank will fill up with air from the open vent with the speed of actual fuel consumption minus the reduced flow from the main tank (the reduced flow will depend on the volume of fuel remaining in the main tank and therefore steadily decrease). Same thing with or without pump. 
    As the only thing we want to have going to the engine is fuel we should only have fuel inlets open, if you want air open the air inlets... Leave the back door and one day someone not invited will enter...

    And I’m sorry, I have to contradict you again… A column of air in the header tank does not create an airlock - not as long as the fuel level in the header tank is higher than the outlet from the header tank (unless you fly inverted…).

    I have a see-through header tank so I know that I cannot get all the air out of the tank by venting it. There is always some left at the top. The tank is in conception almost identical to the old "4 minute tube" but with a 7 liter (1.85 gal) capacity and a level alarm built in. It is also placed in the same "behind the seat" position.

    Once I have emptied one wing tank the level in the header tank is lowering and the upper part of the tank filling up with air (yes, I know, not yet the same scenario as the header tank is now my “temporary” main tank vented through the primary wing tank).

    This goes on until the alarm wakes my up and I switch to the other wing tank. By now I have exactly your scenario with a header tank with a closed vent and a major air column on top expected to be fed by the main tank…

    Ta-Da ! Suspense! Will the fuel start to flow from the wing tank to the header tank or will I crash and burn?

     

    An airlock is when air (or vapor) is preventing the passage of the liquid – but this will not happen, in this configuration, until the fuel level drop to the level of the outlet (“Fuel to engine” on the drawing). If there is air at the top of the header tank the fuel will just drip through the air and down to its fuel friends further down in the header tank.


     

    Question for you... you mention "BOTH finger strainers"... one in the main tank - where is the other? Or are you like me having double outlets on the wing tank?  
     
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