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rotax618 last won the day on June 25 2016

rotax618 had the most liked content!

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About rotax618

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  1. Hello! I would like to build a Faceted aircraft like you did. Do you have any information you can share? Cheers José Poejo
  2. rotax618

    My Savannah S model rebuild Blog

    I would be careful if you don’t understand the stress paths, reinforcing random points on a thin alloy skinned structure can give unexpected results - remember the NOMAD tail disaster.
  3. rotax618

    A riveting weekend

    Would help a little if you move the engine forward and use the maximum prop extension. I am basing my opinion on my experience with my Boorabee design, which had a 2 stroke more forward under the wing, a lighter 1.6mmx 127dia tube boom and fabric covered tail. The Boorabee Rearward C/G was limited by a 70kg pilot sitting only slightly more rearward than in your drawing. I admire your concept but I would go back to the moment spreadsheet at this point you will have a pretty good idea of the moments of the remaining unbuilt bits.
  4. rotax618

    A riveting weekend

    Project is coming along well, but just looking at the elevation I can’t help thinking about the C/G without wing sweep. If you haven’t started the wing design yet I would encourage you to consider the possability.
  5. rotax618

    My Savannah S model rebuild Blog

    I got to look at how Groppo vent their tanks, they have a tube from the top of the outer end of the tank, the tube goes out to the wingtip where it is connected to a forward facing U tube.
  6. rotax618

    My Savannah S model rebuild Blog

    I’m sure that you have considered the problem that you will loose some volume because you won’t be able to fill the tanks higher than the bottom of the cap outer body ( probably a good thing to prevent overfilling) and the inner clamping ring will have to be made in 2 halves to go into the tank so will have to be rigid enough to clamp the uneven plastic tank using 3 screws in each half. I noticed that the Groppo next door has flush tank fittings that have a brass screwed cap you can open with a coin, I have no idea how they vent the tanks, the screw caps are only about 25mm.
  7. rotax618

    My Savannah S model rebuild Blog

    They look good Mark, how are you going to fit the vents, doesn’t seem to be too much room on the top of the cap.
  8. rotax618

    Hi All, Need wing Struts for Thruster TST

    I think you may get some of that extrusion from Hughes Aircraft, looks the same as the Lightwing.
  9. rotax618

    520 kg vs 560 kg

    The RAA will not change the max TO weight from the original registration even though you produce a the documentation and photographs and WB of the modifications, at least they wouldnt for me.
  10. rotax618

    Another NEW Savannah XL on its way

    Unfortunately the venting of the tank will also effect the measured pressure, my Sav has forward facing fuel cap vents, they increase the air pressure in the tank. Years ago I built a capacitive fuel gauge for my Drifter using two sheets of copper clad circuit board screwed together with nylon screws and separated by thin nylon washers. I measured the capacity with a Dick Smith kit. It worked OK most of the time but because of the change of chemical content and moisture in the fuel the gauge had to be set for the amount of fuel before each flight.
  11. rotax618

    2:1 Reduction Gearbox

    2:1 is a very bad ratio, needs to be an uneven number or the same gear teeth take all of the power pulses and will soon fail. Ther was a CAM drive Honda with a 2:1 ratio, didn’t last too long.
  12. rotax618

    Elevator Hinge Reinforcement

    Three hinges on a door is always a problem, as the door warps the centre hinge always becomes loose, the elevator hinges on the Sav probably suffer misalignment under load. ICP should offer a repair method if this is a problem on high hour aircraft.