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Synergy Foam Park Flyer Design
  • Hi Guys


    I have been inspired to design a foamy park flyer based on the Synergy airplane that has been featured on this website.


    I couldnt work out how to post pictures on this foru m so i have posted some pictures on the RCG KFm thread


    You can see my posts here


    http://www.rcgroups.com/forums/showpost.php?p=21429986&postcount=4157


    I decided to use a KFm4 airfoil for ease of building


    my big questions are about the Dyhedral that the original plane has.


    Please take a look at my post on RCG if you are interested.


    Many thanks


    Ben

  • That's great! Beautiful drawings. Is that Google Sketchup?

    What you wanted to do is attach a file. If the forum software recognizes an image file, it will automatically show a preview.

    I do not believe the Synergy to be a tandem wing design. It does not have two wings. The rear "wing" is really an elevator. The step in your drawing should be on the bottom.

    Given the significant amount of sweep on the main wing, you may be able to get away without having any dihedral at all.

    This would be a good candidate for a half-size design study to check the stability.

    Carlos
  • Hi Carlos


    I will try and post some pictures on here over the weekend.


    Yes i guess its not a tandem wing design at all really as the elevons dont act as wings.


    What do you mean the step in my Drawing shoudl be on the bottom?



    I would love to try and build a half size model but i am sevearly lacking in suitable foam at the moment!


    Yes the software i use is Google SketchUp. I think its great software especially for this type of thing


    Thanks


    Ben

  • Looking at your drawing more closely, I guess what I saw is not a step. It's the white part at the leading edge of the orange elevator. Is that just a stationary horizontal stabilizer?

    I use regular foamboard foam for my half-size models. The thickness is not to scale, but it also makes them more durable. I fly them in my living room, so most flights end in a crash against a wall.

    I have messed around with SketchUp and was impressed. It still has a learning curve, but a lot less steep than a real CAD package. The price is right, too.

    Carlos
  • Hi Carlos


    No that is not a step infront of the airleron it is just a small stationary horizontal Stab to give me a convenient place for a tape hinge for the arileronand to give some stiffness to the box structure.


    Regarding the half scale model how accurate do you need to be?


    i have access to the very heavy elmers foam board at 5mm thick but you simpley cnanot remove the card from the surface.


    A model made from this wouldhave a significantly heavier wing loading.


    I would assume a half scale model would have to be as accurate as possible to give you any real information about the design?


    Would you also include in the half scale model teh KFm Steps or just make it very simple flat wings?


    I use the pro version of SketchUp at work and it allwos import and export of many file types including ACAD which i find extremely useful.


    The only thing i have not yet figuredout how to do is compound curves. I know this can be done but i just cant figure it out!


    I think SketchUp is Highly underated and is often dismssed as not a "REAL" CAD package but it is very powerfull especialy when you take into considerationall the thirdparty plugs that are now available.


    Cheers


    Ben


     

  • Look at this Pickerel article for ideas:  http://rcadvisor.com/pickerel-prototype-2-design-choices

    Elmer's foamboard with the paper is too heavy. The paper can be removed, but it is a pain. I soak it in alcohol for a long time. I wouldn't even build the full-scale version with the paper. You don't have access to foamboard with easier to remove paper?

    I add the steps to the half-size versions. I use a glue stick to put them on. Very quick and easy. I round out the leading edges. I leave out the support wood.

    Accuracy is important, but ease of building is just as important. My full-size versions always seem to fly about the same as the half-scale prototypes. Maybe I just get lucky. It is much better to crash the half-scale version as you figure out the CG than to crash the bigger one.

    Wish I could help you with the compound curves in SketchUp. I just have not used it much. Third party plugs? I need to look into that.

    Carlos
  • Yeah the elmers stuff is far too heavy i leant that the hardway, i built a 1meter wing span biplane from it that was far to heavy to fly, couldnt even get the thing to balance properly! I scraped the idea and rebuilt from Depron and its a far better model on all fronts.


    I guess even with a a half scale model you should also use 3mm Depron instead of 6mm of the full size to be as accurate as possible.


    Regarding SketchUp, I reccomend you look through there website you can find alots of info


    There is free online magazine that keeps you uptodate with the lateste developments and what is possible with SketchUp, its called CatchUp and can be found here http://sketchucation.com/catchup/ I had completely forgotten that in one issue they show you how to model a plane!! i will be readying that one again. This is where youcan learn most about all teh different plugins available for SketchUp.


    Here you can sign up for a news letter that can be interesting, it never takes long to read. http://sketchup.google.com/intl/en/community/sketchupdate.html


    Here is a good list of resources for learning about SketchUp http://sketchup.google.com/intl/en/community/resources.html


    I think SketchUp is tragetted primarily at Architechts but it has many many powerful uses.


    Can you tell I'm a big Fan!


     


     

  • Thanks for all the pointers about SketchUp!

    Carlos
  • I forgot to mention. Regardless of how hard you try, a half-scale version will never fly the same as the full-scale version. That is because you cannot scale down the air molecules. I don't build them as a substitute for trying out the real thing. I build them as a quick and easy way to learn more about the flying characteristics of a design.

    Having said that, you have the right idea. The more accurate they are, the more you can learn from them.

    I suppose another option is to build a full-scale version but do not put a radio or power system on it.

    Carlos
  • My biggest problem is to find enough materials to build the full size let alone a Scale model!


     


    Will keep you posted to my progress.

  • Oh. LOL

    By "full-scale version" I meant "full-scale RC version". In other words, the final size that you want to build your model at.

    My smaller versions are exactly half the size of the final RC version, which is why I call them "half-size".

    Carlos
  • You might try this:


    true $50.00 + shipping but that is 50 sheets....

    I use the white stuff, ( not shown on the web site ?? ).  Just mist it with water and wait a few seconds, peel paper off.  Simple easy cheap.
  • You use plain water to get the paper off? I always use 70% alcohol. Soak it, put it in a garbage bag, and about 30 minutes later it just peels off.

    I'll do a test with plain water. Thanks for the tip.

    Carlos

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