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Scale Modifications to the 1/3 Scale Balsa USA Sopwith Pup

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Scale Modifications to the 1/3 Scale Balsa USA Sopwith Pup

Old 01-14-2015, 03:02 PM
  #151  
AndyF
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When you compare the BUSA airfoil to the scale airfoil, the BUSA 1/3 scale airfoil is 1/2 the thickness of the full size scale airfoil. It is also under camber. So I'll have to trim both the upper and lower side of the rib to get them right.


Andy
Old 01-17-2015, 07:46 PM
  #152  
US185Damiani
 
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As far as aileron travel, the full scale plans call for 6" up travel minimum. and ready for this? down travel is 10"!
Nature of the undercambered airfoil. Adverse yaw is intense so the rudder gets used a ton!
Old 01-17-2015, 09:23 PM
  #153  
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Thank you for the full scale travel info.. 6inch up translates to 2 inch 1/3 scale. Maybe a little more for the 1/3 will be fine.. I hope
Old 01-18-2015, 07:43 AM
  #154  
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I purchased an inexpensive throw meter from Hobby King. You may want to consider getting one. I would say 25-30 degrees would be a good starting point for any model. My DX-8 has triple rates so I have it set for 100-80-60 in case I have to soften things up in a hurry.

http://www.hobbyking.com/hobbyking/s...arehouse_.html

Old 01-18-2015, 07:54 AM
  #155  
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The pup will need huge throws especially if the gap is not tight
Old 01-18-2015, 09:40 AM
  #156  
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Start with the plans and go from there. Usually the plans are right on or just a little too much.
Old 01-20-2015, 07:33 PM
  #157  
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thinking about the up vs down throw. Seems as if the Pup designers were using differential in the ailerons. In this case more Down than up.. Interesting!
Old 01-20-2015, 07:52 PM
  #158  
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Most of these biplanes fly best when using differential to avoid adverse yaw and high speed stalls. I generally make down 50% of up and work from there. So far, so good.
Old 01-20-2015, 08:14 PM
  #159  
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Yes you are right.. i just find it interesting that they did use differential just opposite from what we do now..
Old 01-20-2015, 08:26 PM
  #160  
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Unfortunately the nature of the beast with a closed aileron cable system and undercambered airfoils is reverse differential. with good rudder useage, the adverse yaw isn't much of a factor.
My Hangar 9 Camel is much the same way.
Unfortunately it is almost impossible to get the type of differential we're used to on this type of setup.
Old 01-23-2015, 03:19 PM
  #161  
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Looking good. But don't forget that the kit has the fin flat on the stab. The real plane has it above. I used fiberglass arrow shafts to get this done on mine. JimB
Old 01-23-2015, 07:46 PM
  #162  
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Hey Andy do you still have the lathe for sale ? I tried pm'ing you but know answer.
Let me know,
Thanks
Old 01-23-2015, 08:01 PM
  #163  
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Originally Posted by bracketman View Post
Hey Andy do you still have the lathe for sale ? I tried pm'ing you but know answer.
Let me know,
Thanks
Oh bracketman, I am sorry, I never received a notice on the PM. I just sold it this afternoon. I was going to take it to the SWAP meet at Kalamazoo, MI tomorrow but one of the guys in our club wanted to take a look at it before I went up there. He handed me cash.

I'm sorry I didn't see your PM earlier.

Andy
Old 01-25-2015, 04:46 PM
  #164  
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Hey U Guiz! Come check out my latest rebuild thread

http://www.rcuniverse.com/forum/cras...l#post11969109
Old 01-25-2015, 04:46 PM
  #165  
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Hey U Guiz! Come check out my latest rebuild thread

http://www.rcuniverse.com/forum/cras...l#post11969109
Old 02-24-2015, 08:11 PM
  #166  
AndyF
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I've had to put this thread on hold. We sold our house and will be moving in a couple of weeks so I'm busy packing up my shop. It will be at least three or four months before I can get back to working on the Pup. I'll let everyone know once I'm back up and running.

Andy
Old 05-15-2015, 06:38 AM
  #167  
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We are in the new (much smaller) place. I am starting to build shelves in the garage in hopes that I can clear enough room to start working on my Pup again. I'm thinking that it will probably be mid summer before I am back at it. I just wanted to give a quick update.

Andy
Old 05-15-2015, 07:56 AM
  #168  
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I always look forward to posts on any and ALL Balsa USA stuff ! So I am glad to hear you are getting closer to building time again.

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