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Undercamber


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My autumn/winter project is a scratch built Lancer 72, a shoulder model originally for 3ch. r/c or freeflight and of some vintage.
I intend to remove the dihedral as advised by forum members on a previous vintage model.but do I need to change wing section from undercamber to flat bottom'
I have just read an article about a JUNIOR 60 having the wing flattened and the undercamber removed and wondered if this would apply in my case.
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Why would you?
 
In fact, why remove the dihedral? One of the things that gives "vintage" models their beautiful looks is the dihedral...I'd only reduce it a tad if I were you. But I'm not...
 
If it was designed for 3ch, why not leave it as it is, but if you feel the need, then go ahead, but you don't need to change the section, no.
 
HTH
 
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Sorry, I should have said that am converting to ailerons, hence reduction of the dihedral.
The Junior 60 that I mentioned had also been converted to ailerons and wing flattened so I could understand the necessity to do this but I do not know if it is absolutely  necessary to remove the undercamber and what would be the benefit (or not) of doing this.
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Well the section is what makes the J 60 such a floater. Remove it and you wont see it fly like a J 60 no more!
 
But why ailerons for pities sake? Use decent bandage round the centre section and fit a big rudder and you'll be rolling and stall turning like a pro. But WHY?????  The whole essence of a J 60 (and presumably your Lancer) is to float around and for you to nudge her.  I can JUST about see why people add ailerons to a SUPER Sixty (the quintessential model plane to my wholly biased eye), but a J 60???
 
Please Geoffrey, reconsider this planned travesty.  Vintage models do not need ailerons and will not reward you for them.
 

Edited By David perry 1 on 24/07/2010 20:15:31

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My take on this is, 'it depends what you want to achieve'
 
If you want to build an accurate repro of the old Lancer 72, that will react and fly as the orginal, then, as others have already mentioned, why change it.
 
But on the other hand, I can also accept the view that maybe you like the plane but want to modify it to add your own personal dimension to it. In other words, you dont need to do it, but you want to try it. With this view, I would say give it a go and see how it turns out. For sure a flatbottom wing isn't going to give you the same floaty lift, and without dihedral you be losing stability, so long as you know that i'd say give it a go.
 
Final thoughts..
 
You can always build another wing to experience the difference! I have a little Monocoupe 90A parkflyer for which I built an aileron/flap wing and a standard dihedral wing. It's a real handful when I'm flying it with the aileron/flap wing and an absolute joy to fly with the stock dihedral wing.
 
sparks
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You're welcome Geoff. I think you will find that the little bit of extra time to build another wing will be worthwhile.
 
If you are doing this for a model with struts, (ie something other than the Lancer) don't forget that the strut mounts will need to be in slightly different places on each wing.- don't ask how I know this...
sparks
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Is this your Lancer? Pretty isn't it.
This one is obviously for free flight.
If your Lancer's structure is going to end up anything like this I would not change the wing section, maybe only reduce the dihedral a bit and use relatively small, scale size ailerons. They will still have more than enough power for any manoeuvre such a design could be expected to perform.
If you want to do snap rolls and high g outside loops - pick another model!     
 
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YES IT IS!
Fantastic to see what  the  finished model looks like. It appealed greatly from the plan and I am not disappointed. I am now at a crossroads in deciding what to do!.
I think that in the spirit of things I really ought to stick to the original concept of 3 channel, but I do have this niggly feeling that I would like to try 4 ch., so maybe I will construct two wings
I think the only other thing is that I will go for the alternative option of an upright engine.
Thanks for the photo.
Do you have any idea what year it is from ; it is not stated on the plan ?
Geoff.
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Hey guys,
Just looking at the photo's, the Lancer reminds me of another great plane of around the same era (or that style anyway) the Daddy-O,..
 
.'...derived from Thayer Syme's RC version of the McGuire Daddy-O and re-engineered by Stevens AeroModel'
 
I love the lines of both!
sparks
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