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Thread: The Techpod!!!

  1. #21
    Techpod designer Hobby UAV's Avatar
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    going to try to go flying this evening . Going for an hour + flight . Ill be posting the video ASAP. If anyone wants to watch , ill be at the cascade r/c airfeild in snohomish around 5:00 pm tonight .

    I want to make it clear to everyone . I am raising the funds to have the aluminum molds made ( 2 x $12,500 ) plus the fist production run of molded EPO techpods through kickstarter .Please go to my project page and pre-order now . pre-order here !!

    If you dont pre-order I won't be able to bring everyone this cool airplane . I'll be stuck to what i can produce in my garage . won't be as cheap and wont be molded EPO.

    @Dionysos
    The pretty colors are cool and all but they do serve a higher purpose . a run of xfoil (which produced to charts in question) takes maybe 45 seconds . These are just 2D calcs . The reason for " all possible " Rn , alpha combos is to compile them into a 3D " lattice " to calculate an airplanes performance not just an airfoils . Like this .


  2. #22
    Pilot Dionysos's Avatar
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    Hi,
    I get your point. So what did you optimize the plane for?

    Dio
    Latest Crafts: The Anti-Gravity-Machine, Carbonator, Guava 2m, Wunderwaffe I, Wunderwaffe II, Uberwaffe, Plankton v2, TBS discovery

  3. #23
    Techpod designer Hobby UAV's Avatar
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    Ok,
    got out. got some flying in , but I left the RX antennas behind . so no fpv video . flew for a timed 21:45 minutes with one land / take off and many fly byes and 4 or 5 climb outs . got some good cell phone shots of slow flybys . charging the lipos . I will post the numbers when they are done . video will take a sec to get uploaded to youtube . its on my friends iphone and i have android so hes got upload it first ....


    Dio
    the picture shows here its optimized operating point .
    Thank you for giving me the chance to explain .

    wayne

  4. #24
    Techpod designer Hobby UAV's Avatar
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    ok got one uploaded shows a full flaps landing .
    Last edited by Hobby UAV; 27th August 2012 at 01:30 AM.

  5. #25
    FPV Baby!!!! noxnflame's Avatar
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    That looks great! I cant wait to see you succeed on this one! I have a feeling it's gonna be a hit.
    Good luck!

  6. #26
    Co-Pilot StompAE86's Avatar
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    Is there room for a HD cam anywhere... looks like the dome on the front only holds the flight cam. Also whats the difference between this and all the other long endurance high wing trainers? Ie skywalker Is the whole idea that your going for just a least draggy airframe possible? I mean its bulk money to invest into something that will just get copied bu HK etc if its successful, I mean best of luck to you just curious thats all... Looks the biz thats for sure.

  7. #27
    Pilot Dionysos's Avatar
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    Hi,
    I'm still not getting it: You are getting a (cl/cd) of 117, or in other words a (gamma) of 0.49 degrees. That's utopic. Around cl/cd=20 would be a good "theoretical" value for a plane of that size, even that is too high, in real life situations you can aim for something like 10-15.

    An ASW high performance manned glider with aspect ratio much larger than yours has a glide ratio of 50 + with related (gamma) of ~1.1 degrees.

    To calculate the plane polars you just need to step through every flap/elevator deflection, i.e. in 0.5 degrees steps and good.

    Vortex Lattice is simply a way to reduce a 3 dimensional "problem" to 2 dimensional one, thus reducing computational power. The wing is split into different panels, somewhat similar to FEM and that's it. But you cannot take into account any interference of let's say fuselage/wing, horizontal stabilizer / vertical stabilizer, so there is quite a high degree of uncertainty, especially when evaluating drag.
    In order to do so, you must run a real 3d simulation, with Ansys for example, but that's like to shooting an ant with a bazooka.

    But never mind, it flies and looks nice. I'm sure you learned a lot when doing all the calcs.

    Dio
    Latest Crafts: The Anti-Gravity-Machine, Carbonator, Guava 2m, Wunderwaffe I, Wunderwaffe II, Uberwaffe, Plankton v2, TBS discovery

  8. #28
    Navigator
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    just pledged on kickstarter. Very nice

  9. #29
    Techpod designer Hobby UAV's Avatar
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    @ stompae86

    drag is directly proportional to flight time . cut your drag in half and double your flight time .(yes that is "perfect " world lab speak ) the point is reduce drag increase flight time . as for the Chinese and HK . You have to understand their culture . they will not copy a Chinese product produced from a Chinese company . and BTW the techpod will most likely be on hobbyking . Bulk money ? its priced at $200 retail . the kickstarter price of $240 includes shipping . I had to average out everyone and add it accordingly . the skywalker x-8 goes for $200 and they are actively producing a massive quantity . their production cost are way lower yet no one complains .the techpod comes with a cameraquality dome and pan and tilt . this ain't no trainer . I would be more then happy to go head to head with any one of the sky walker line or any other of the cheesy "trainers" . trainers are made for one thing , being easy to fly , not endurance . I will be in Moclips,washington this labor day . I am going to go play in the sustained 15 to 25 mph wind they get there on the beach . Any one care to take up my challenge and fly your bixler,skywalker,whatever next to the techpod ? I have a few campground spots near town . I have power and water hook up or bring your tent .

    @Dio
    thanks you for taking me to task . yes the 117 cl/cd only includes the wings etc.... yes XFLR5 is wonky at drag prediction . yes VLM it half ass 3d . thats why i used it for initial performance estimates . the real drag reduction came from using solid works flow module ;-) ( I sense a cool picture coming )


    @ all
    Got an hour flight in yesterday . used 5100 ma on a 3-cell. editing the video now . I will have it posted soon if not tonight after work . thank you everyone for you kind words and support !

  10. #30
    Navigator robwatkiss's Avatar
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    Starting my AeroEng degree in a month's time so particularly interested in your modelling and simulation work. Keep it up!

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