R/C BG Help

Discussion in 'Rocket Boosted Gliders' started by aerostadt, Dec 29, 2017.

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  1. Dec 29, 2017 #1

    aerostadt

    aerostadt

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    I am looking for help for an R/C Boost Glider that I got from the estate of Frank Hunt, who was an active UROC member and UROC NAR adviser. Frank passed away several years ago after making many contributions to the Club.

    Attached are some photo's of the glider. I tend to think that Frank did not fly this glider and may have had commissioned someone to build it for him, although, I'm not sure, Frank might have also been a model airplane enthusiast. The wingspan is 31.75", however, with a Spektrum AR0400 receiver, two HS-55 servo's, and a 1s 3.7 v Lipo battery weighs only 6.5 ounces. I was thinking of setting the transmitter on acrobatic/dual aileron, but I noticed that the transmitter has a sailplane selection, too. I am wondering where the CG goes on a plane like this. The motor pod takes 24 mm diameter motors. I am not planning to fly this until the weather gets warmer, but it would be nice to fly it sometime in 2018. Any advice would be appreciated.

    001.jpg 002.jpg 003.jpg
     
  2. Dec 29, 2017 #2

    Onebadhawk

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    I've got an easy one from setting up RC aircraft...
    The centre of mass should definitely be directly under the centre of lift...
    But the mass changes after the burn..
    Split the difference..

    Teddy
     
  3. Dec 30, 2017 #3

    KevinM

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    Wow, that looks like something that was inspired by the Edmonds ARCIE. (I've built two now, this is the most recent.)

    DSCN3662.jpg DSCN3664.jpg

    What transmitter are you planning to fly it from? How much RC experience do you have? I ask because your experience and the capabilities of your transmitter could affect the complexity with which you might like to set up the controls. Also, knowing the setup that works with an ARCIE you might not want to set this up with just basic aileron controls - some form of differential or false elevator control is probably a good idea.

    What are the dimensions on your model? Wingspan, root chord (including ailerons), sweep-back, tail span, distance from wing LE to tail LE? Can you sketch up a quick drawing?

    KMc
     
  4. Dec 30, 2017 #4

    burkefj

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    Yeah, looks like the Edmonds design where you just have aileron for turning only, in this format if you balance for glide, the motor and pod are ahead of the wing LE by design so should be stable for boost, if the stack boost Cg is at or ahead of the le it's probably ok. It's light enough you can try glide tests for the glider cg Try this review, it shows a review of an arcie ii with cg markings and dimensions. https://www.rocketreviews.com/edmonds-aerospace-arcie-ii--by-bob-cox.html
     
    Last edited: Dec 30, 2017
  5. Dec 30, 2017 #5

    aerostadt

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    Thanks for the advice everyone. I will check it out.
     
  6. Jan 2, 2018 #6

    kjohnson

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    That is an original Edmonds ARCIE, the later one with the solid preairfoiled wing that KevinM posted was the ARCIE II. This version has a built up fuselage and a wing made from two skins over a row of ribs that were glued in a pattern like this /\/\/\/\/\/\/\.
    There were very few of them kitted. Flies great on D12-3 and E9-4.

    kj
     
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  7. Jan 2, 2018 #7

    DuaneW

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    That is the original Edmonds ARCIE. Rob simplified it for the version you have. I still have my mk. 1 version in the box.
     
  8. Jan 2, 2018 #8

    aerostadt

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    I do have the ARCIE. It looks like I have the original version. I did sand an airfoil into the wing, but I tend to think that there is not much camber there. I cannot tell now, because there are wing tip fins glued on. There is definitely camber on Frank Hunt's red glider as seen in the photo. There is a bad tilt in the wing on my ARCIE with respect to the fuselage. Evidently, I did not glue the wing on straight. I read where some ARCIE fliers noted a death spiral due to perhaps a weight mismatch on the wings. Perhaps, some weight to one of my wings might correct for the wing tilt. Also, I need to revisit the engaging of the elevon horn with the wing tabs. I need to do trial tosses and check out the electronics, too.

    001.jpg 002.jpg 003.jpg

    004.jpg 005.jpg 006.jpg
     
  9. Nov 29, 2018 #9

    aerostadt

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    OK, I have come back to this project after about a year of other distractions. It looks like I did not pay enough attention to all the good advice that I got here about this boost glider being of the Edmonds ARCIE design. Especially, KJ and Duane point out that this was something like the first ARCIE kit design. That is amazing, because this model looks so much different than the ARCIE II. The model is bigger and the wood is entirely different.

    So, you can see how far off my thinking was from the attached photo's, because I've got 2 servo's crammed into the flight compartment. As I result the servo arms are very short and everything is going to be too packed together. So, from what everyone has stated about the ARCIE, I need to put in just "one" servo. Then I can balance the model like the ARCIE with the c.g. being on the wing (maybe somewhat to the rear of the wing) and getting a basically level flight. Then I set the Spektrum transmitter to Dual Aileron Wing connection to direct the model to the left or the right. Is that correct?
     

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  10. Nov 30, 2018 #10

    MaxQ

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    If your ailerons will only act as ailerons (each one moves opposite of the other one) and will not need to also act in unison as flaps (down) or provide reflex (up) then yeah, only one servo is required.
    One servo arm with a push rod on each end/side will move each aileron in the opposite direction of the other one at the same time.

    I have the Arcie II...started...never finished it as I built the Aerotech Phoenix instead.
    But still have the instructions.
    The Arcie II has the servo battery and Rx in an open exposed bay in the nose and not in an enclosed fuselage. This allows the battery to be moved forward or backward to balance the glider.

    Each wing has a diamond imprinted on the top surface, 3/4 of an inch out from each wing root edge, aprox. 2 7/16 inch back from the leading edge of the wing.
    ...that's where the balance point/CG is...….



     
    Last edited: Nov 30, 2018
  11. Nov 30, 2018 #11

    aerostadt

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    Thanks Maxout.

    I, also, have the Arcie II and along with the instructions. I know that I have flown it at least once with no success. It went into a fast dive and did not pull out. I did see a Arcie II perform well at a Hellfire meet several years ago, so I know that it can done. I am not sure the airfoil on my Arcie is very substantial. The airfoil on this current red glider is quite substantial, so perhaps that will help. I keep thinking of going back to my Arcie II, but so far I have not gotten around to it.

    I have thought of cutting away the sides of the fuselage of the current model, so that I can extend the servo arms beyond the fuse, but I would have to cut away half or more of the sides of the fuse. I am not keen about this idea.
     
  12. Dec 1, 2018 #12

    Crawf56

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  13. Dec 1, 2018 #13

    MaxQ

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    Did not pull out of a dive......
    Did it survive?
    Was the CG correct on it?...sounds very nose heavy - were you able to do any test throws with t?
     
  14. Dec 1, 2018 #14

    aerostadt

    aerostadt

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    It survived enough that I was able to re-build it. I thought I had balanced it correctly. As I said I may go back to it someday. I see on Rocket Reviews that flyers had made many good flights with the Arcie II. If and when I go back, I will do test throws. I may not have done test throws the first time.

    I am re-looking at the two-servo's option on the red glider. I may be able to make some tweaks to make it work better.
     
  15. Dec 3, 2018 #15

    aerostadt

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    Kj,
    That sounds encouraging. Did you use one servo or two?
     

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