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What is the Cozy main wing airfoil?


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That is correct, it is an Eppler E1230 airfoil -- the same used by the Long-EZ.

It is a MODIFIED Eppler 1230 - it is NOT the stock 1230 airfoil that you will find. The modification involves removing some (but not all) of the T.E. reflex, but no-one has ever been able to get a perfect description of exactly what was changed. The airfoil has been reverse engineered, however, from the L.E./COZY templates (innacurate though they are, being on paper and all).
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  • 3 years later...

..... I feel your pain.:D

I never got a real warm and fuzzy cutting out 2 pieces and then trying to get them aligned correctly to make the template. I'm sure my drawings from the 1980 version are worse than what you are working with.

 

I also have a full set of drawings of the Berkut. These plotted on a larger format so the airfoil is in one piece. Much better to work with.

 

What really amazes me is why nobody has ever offered the templates pre-cut out of aluminum? I cut mine out of formica and wasn't real happy with them. Since then I got my Berkut drawings and re-cut them in aluminum with much better results.

 

Now if I could have just ordered them from ACS, that would have been the way I would have gone .... for sure. It seems that it would be a good way for them to support the Cozy builders.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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.... as a side note:

I'm cutting my canard out today. I'm REALLY not looking forward to cutting out the elevators.

 

EZ_Ahab ....... get your butt back here to the states (in one piece!) We need you here!

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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I just felt as though the aluminum would stand up better.

 

What I did with my canard templates is cut them per plans and the cut another set about an 1/8th of an inch larger. They are all matched up to the same nail holes for mounting on the foam, but I will cut the larger profile first and then sand them down to the plans template. That's the way a Berkut builder in our EAA chapter did his wings.

 

Another technique is to hotwire the larger template and then hotwire to the plans template. The second cut is only removing a small amount so it's said to be an easier, more accurate technique.

 

Anyway, the templates will be durable enough to be used by other builders for some time to come. I'm afraid that if I sanded down to the formica templates, i would distort them. Also, the aluminum machines better.

T Mann - Loooong-EZ/20B Infinity R/G Chpts 18

Velocity/RG N951TM

Mann's Airplane Factory

We add rocket's to everything!

4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done

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Here is a layout of the original E1230 vs Rutans mod.

 

http://www.canardzone.com/forum/attachment.php?attachmentid=642&d=1175249610

 

Now remember that because the cores are cut perpendicular to the spar, not along the true chord line, the E1230 looks thicker. It actually is not. The main difference is the removal of the undercamber, which I assume was done mostly to make it easier to build.

Adrian Smart

Cozy IV #1453

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..... The main difference is the removal of the undercamber, which I assume was done mostly to make it easier to build.

That's not my understanding. I believe it was done to lower the wing's moment coefficient.
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