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Introducing the Open-EZ Tandem, a 2-place tandem canard


Jon Matcho
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Please see this post for important information regarding an update to the templates.

There have been many inquiries about how to build a Long-EZ, with the main issue being how to locate the Long-EZ paper drawings. They're simply not available, and there are no signs that they will become available in the future.

There is now an alternative -- the Open-EZ. Derived from the Long-EZ and made available to me anonymously over the Internet, Open-EZ "plans" consist of 14 drawings labeled the same as Long-EZ drawings for purposes of synergy.

At a glance, you can consider the Open-EZ to be a Long-EZ compatible clone. Digging deeper and comparing Open-EZ drawings (revision 5) to Long-EZ drawings, you will notice a few differences, with the most notable enhancement being the addition of a measurement verification system on each drawing.

DISCLAIMER

These Open-EZ drawings are being made available solely for educational purposes and provided without any support or warranty whatsoever.   If you choose, through your own free will, to build, operate, or pilot an aircraft that was built using Open-EZ drawings, then you hereby acknowledge the risks and responsibilities associated with such an activity, which can involve death, injury, and property damage to you or others.

ON YOUR OWN

For the experimental aircraft home-builder, in theory, you can conceivably build and fly an Open-EZ (heeding the prior warning) by doing the following:

  1. Read this Open-EZ post.
  2. Optional: Purchase the Rutan Aircraft Factory CD-ROM Encyclopedia from TERF.
  3. Purchase the Roncz canard plans from Rutan Aircraft Factory.  Update:  Roncz canard plans are no longer available from RAF and will soon be available as part of the Open-EZ project.
  4. Download the Open-EZ drawings and print according to the instructions in the included README file.
  5. Update the Long-EZ plans AND Open-EZ templates with information from the Canard Pusher newsletters (also on the TERF CD).
  6. Build an Open-EZ.
  7. Determine whether your creation is airworthy (this is entirely your decision!)
  8. Enjoy your accomplishment.

I do hope that everyone appreciates and welcomes these drawings into the community, and that someday soon someone takes on building and flying an Open-EZ.  Bert Rutan requests that aircraft built from these plans not be registered as a Long-EZ, in order to less his liability

Any and all feedback is entirely welcome!

Enjoy!

Edit Jun 2022:   links to the Roncz Canard plans, Builder's Manual and several cad-drawing sources are in this thread.   All the Canard Pushers are available on Marc Zeitlin's www.cozybuilders.org website.  Several aircraft have been built from these plans.   -K. Ashton

Edited by Kent Ashton
Updated post to be current and pointing to the official download location here.

Jon Matcho :busy:
Builder & Canard Zone Admin
Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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Jon:

Last night I downloaded the drawing set for the Open EZ. Today, I printed a set of the drawings before I looked at them on my computer.

What I found surprised me in that the Open EZ drawings are identical to the Long EZ Templates A-1 through A14. I know, because I have a licensed, unused set of drawings for the Long EZ. In comparing the drawings, the only difference I see are the measurement marks on the corners of the drawings that you mentioned in your notes.

The printer at the print shop I used is high quality, and the mesurements agreed with the dimensions on the finished prints. Nice, Now I have a full set of spare templates, thanks!

What is interesting is that with the Terf CD and the Open EZ drawings (templates really), a new Long EZ could be scratch built as long as the plans changes and updates in the carnard pusher newsletters are considered.

So why not call it a Long EZ? Where did these things come from; the Long EZ Good Fairy?

Looks like building a 2006 Long EZ is now a no brainer for those in search of those hard to find Long EZ templates.

JR

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While I personally printed and verified my dimensions against Long-EZ copies, as well did Avpro56 with his ACTUAL Long-EZ drawings, I encourage others to test a page or two as well -- to verify the ability to generate these prints consistently.

Keep in mind that each of YOU need to do your own quality assurance by verifying the printed dimensions using the simple procedure mentioned. This was previously done by RAF, but now must be done by anyone looking to use these "out in the wild".

Jon Matcho :busy:
Builder & Canard Zone Admin
Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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Tony is correct - as long (no pun intended) as the template drawings are dimensioned, what difference does it make whether they are quarter scale, half scale, zillionth scale, (provided they are legible) or full scale?

 

You might find the following interesting.

 

Let me quote: "FULL SIZE Drawings - I received a question as to why all the drawings for ribs, etc. are not full-size to allow for tracing to the part. The answer is because so many of the ribs, etc., are so long that they won't fit any convenient paper size and that (sic) paper that long can shrink and thus effect (sic) the size of the part. If you use the following hints you will find that converting the scaled-down drawings will be a very small percentage of the work required to build your aircraft:

 

Do not draw the part full size to transfer to the material; transfer the

dimensions directly to the wood or metal. (ball point pen on wood; BIC

Banana on metal). Have a wife or friend read the dimensions from the

drawing or grid while you use a scale to plot them on the material. This

is much faster than looking back and forth and eliminates errors. Buy a

Stanley metal tape, rule no. B61-112Y. This is a 12 foot retractable tape-

rule with graduations in tenths of inches, not 1/16ths. That tool alone

will save you many hours of conversions."

 

Variviggen News No. 1. May 1974

Rutan Aircraft Factory/P.O. Box 111 Valley Center, KS. 67147

 

Also: "Be sure you are using the decimal 12" rule and tape measure, fractions are for carpenters!"

 

Page 3. Variviggen News No. 2. Oct 74

Rutan Aircraft Factory

Burt and Carolyn Rutan

Building #13, Mojave Airport

P.O. Box 656, Mojave, Ca. 93501

 

 

 

FYI, that was written almost 32 years ago.

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The plans and manuals are available on the TERF CD set. It's available from TERF, and costs USD$295 plus shipping.

 

There are no pages missing from the templates that I'm aware of.

 

-dave

This is not a sig. This is a duck. Quack.

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  • 4 weeks later...

IM not going to stress to much about getting the canard plans. with all you all are doing to get the open ez plans coppied and fixed im sure the canard plans are soon to follow. im not trying to get off cheep i'll be willing to pay for them latter when i start working.

Im still trying to find a place to build mine. cant justify spending 3000 dollars on a workshop when that same 3000 could go to the plane.

 

I appreciate all your post. Whith all I have read I fell like i know exactly what I want in my bird and ready to start building.

 

Lynn

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velocity dreamer said:

IM not going to stress to much about getting the canard plans. with all you all are doing to get the open ez plans coppied and fixed im sure the canard plans are soon to follow. im not trying to get off cheep i'll be willing to pay for them latter when i start working.

Right... don't worry. They're available now if you want/need them, and I expect them to be tomorrow as well...

Quote

Im still trying to find a place to build mine. cant justify spending 3000 dollars on a workshop when that same 3000 could go to the plane.

If the workshop is attached to your house, you won't go wrong with sprucing it up. Understand that it's your most important "tool".

Quote

I appreciate all your post. Whith all I have read I fell like i know exactly what I want in my bird and ready to start building.

That's good! However, prepare yourself for becoming aware of everything you don't know. Just press through every milestone and all will be well (so I'm told...) :).

Jon Matcho :busy:
Builder & Canard Zone Admin
Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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Hi All,

 

While on the subject of templates, does anyone know what Dave did on the Berkut to improve the wing airfoils. He stated way back in a magazine article that he found the EZ airfoil templates to be inaccurate and fixed them on the Berkut. I would like to do the same for my Long EZ. I know the Eppler 1230 airfoil plots are somewhere on the web but supposedly Burt used a "modified" Eppler airfoil. What was modified? How can I check the templates for accuracy the way Dave did? If we're doing it we might as well do it correctly.

 

New subject: What do the large rudder plans consist of that RAF gets $20.00 for?

 

Thanks much,

 

Bob

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The rudder plans are on the TERF CD, so if you pick that up you'll have the rudder plans as well. [NOTE: The TERF CD has no templates]

 

I believe the original rudder was a much smaller surface area than the larger rudder plans. The larger rudder is similar to what you'd see on the Cozy etc.

 

There may be inof on that set of plans as well, just haven't gotten around to reading them yet.

Bob Hassel

Cozy Plans #749

Santa Fe, NM

 

http://www.cozyworld.net

http://www.hassel-usa.com

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Hookr55 said:

...does anyone know what Dave did on the Berkut to improve the wing airfoils. He stated way back in a magazine article that he found the EZ airfoil templates to be inaccurate and fixed them on the Berkut.

Which magazine and issue? Dave here (dpaton) is working on "correcting" the airfoil drawings, as does anyone who has to piece together 2 or more pages to get things to align.

Richard Riley can give the most thorough answer to your question. I understand that the only difference is that some of the Berkut wings were molded (some were foam core) and were skinned in carbon.

Quote

I would like to do the same for my Long EZ.

Do what? You don't know what, if anything, was changed with regard to the airfoil yet.

Quote

I know the Eppler 1230 airfoil plots are somewhere on the web but supposedly Burt used a "modified" Eppler airfoil. What was modified?

Do not build a Long-EZ with the "official" Eppler 1230 airfoil! Long-EZs, Cozys, and AeroCanards use the same modified Eppler 1230 airfoil. Burt Rutan modified it on purpose to improve overall flying characteristics in the context of a canard aircraft. Don't ask me what those were, but I trust Burt's judgement and would not want to mess with it -- I do not have the knowledge or skills.

Before I speculate whether Dave R. had the knowledge or skills, I'm just going to stick my neck out and bet that Dave did NOT change the airfoil and only changed the construction of the wing.

Quote

How can I check the templates for accuracy the way Dave did?

I'm not clear as to what Dave did. Assuming the article exists and said exactly what you said here, it's still not clear to me as to whether he changed the drawings/templates or changed the airfoil itself. I've read a lot (all?) of the Berkut articles and don't recall the mention so why I'm not much help right now.

Quote

If we're doing it we might as well do it correctly.

What is the problem you're looking to solve? Is there a problem beyond taping the drawings together? The problem is not in the airfoil. IMHO, that should NOT be touched.

Jon Matcho :busy:
Builder & Canard Zone Admin
Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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To the best of my knowledge, the mod to the Eppler 1230 involved flattening the lower side of the TE and a few other tweaks to make the airfoil easier to construct on a flat bench in 2 car garage. The benefits on the plane were secondary and minimal. Of course, I've never seen an offical report on this from RAF, so consider it 2nd and 3rd hand, and as reliable as the game of telephone was when we were all kids.

 

:D

 

The airfoil templates underwent some distortion in the copying process, and have been distored on every single Long built since 1979 (along with almost every other template sheet), except those that took the time to calculate the distortion and redraw the airfoils completely, as I am (very few builders I'm guessing).

 

As it stands right now, the biggest component of the distortion, by an order of magnitude, is a small change in the length of the taper to the TE, and is well within the range of builder tolerance. My taped together airfoil prints are cut apart and reassembled, and are currently hanging on a wall in my garage under a sheet of vellum to be redrawn onto new paper for rescanning when I stop working until the wee hours every day here at work. The difference, aerodynamically, between my redraw and the plans airfoils will be insignificant, and my reasons for working on the airfoils are purely in the interest of completeness (they're one of the easier parts of the template concatanation to do as well). The flying character of the wing will be unaffected.

 

-dave

This is not a sig. This is a duck. Quack.

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Hi Gents,

 

I'm certainly not looking at using the original Eppler 1230. I did a quick plot last night and can see the lower surface camber that exists in the aft 30%. I'll find that article that Dave R. was quoted as seeing some inadequacies in the original printing of Long EZ wing templates that he "improved" upon.

 

I'm just interested in improvements that I can make that take advantage of newer methods without messing with "proven" designs.

 

I learned at a young age when building soap box cars (my first fiberglass exposure) that many little things can add up and win races. I lost my last race by 12" to a guy who went to the national race and placed third. :sad:

 

I'll keep monitoring for any activity on the template subject, otherwise my original plans version are just fine.

 

Thank you for the open-EZ project, this information makes me feel more comfortable with my unregistered Long EZ plans.

 

Bob

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dpaton said:

To the best of my knowledge, the mod to the Eppler 1230 involved flattening the lower side of the TE and a few other tweaks to make the airfoil easier to construct on a flat bench in 2 car garage.

I have never heard that before. I understood that changes were made specifically to address flight characteristics. I heard this 2nd or 3rd hand as well.

Very much looking forward to your updated drawings to incorporate into the next scheduled Open-EZ revision (#6). There are several other minor modifications planned (cosmetics), which are outside of your work, which I look forward to releasing. I'll have to merge in with your work, but no problem. Take your time -- I'm in no rush, and everyone already has the ability to begin building an Open-EZ.

Hookr55 said:

I'll find that article that Dave R. was quoted as seeing some inadequacies in the original printing of Long EZ wing templates that he "improved" upon.

I imagine our next exercise will be similar to interpreting portions of the Bible. We could always ask the God of the Berkut... :)

Quote

Thank you for the open-EZ project, this information makes me feel more comfortable with my unregistered Long EZ plans.

Even if you had registered plans, they would still be as useful to you as Open-EZ plans -- no support from RAF, etc. You're in as good a shape as anyone building a Long-EZ today, registered or not.

Marc Zeitlin said:

And has already, for those interested in checking.

Geez, and I though I had the entire forum indexed in my head. Good find! Marc, do you recall the purpose of Burt modifying the Eppler airfoil?

Jon Matcho :busy:
Builder & Canard Zone Admin
Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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Jon Matcho said:

Marc, do you recall the purpose of Burt modifying the Eppler airfoil?

I had heard once that it was to reduce the moment coefficient for the main wing. Having reflex near the T.E. of a wing raises the moment coefficient, and that would entail needing more canard authority (which might have an effect on deep stall susceptibility). Removing the reflex (flattening the bottom) would lower the Cm. I have no idea how accurate that account was.

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Jon Matcho said:

I have never heard that before. I understood that changes were made specifically to address flight characteristics. I heard this 2nd or 3rd hand as well.

That could be quite possible as well. Like I said, it's all heresay. The official news of the new wing design for the Long (CP23 I think) only included that it used a mod'd Eppler 1230, and that the sweep was much less than that of the Vari.

Jon Matcho said:

Very much looking forward to your updated drawings to incorporate into the next scheduled Open-EZ revision (#6). There are several other minor modifications planned (cosmetics), which are outside of your work, which I look forward to releasing. I'll have to merge in with your work, but no problem. Take your time -- I'm in no rush, and everyone already has the ability to begin building an Open-EZ.

Indeed. My mods are mainly for convenience I think. There have been thousands of planes built with the templates as-is, and they fly just fine. I just like the idea of one part, one drawing a little better.

That said, Tony has already done the work once, but those aren't nearly as Kinkos friendly as the PDFs are :D

My going will continue to be slow for another month or so due to daytime job commitments. I've given up on my original target dates, and now I'm just working to completion. I think I'll be releasing the unified drawings one set at a time, so that there is some progress to be shown, and hopefully so that folks can get what they need when they need it. The IP will likely come last however, since it's the very worst in terms of distortion, much to my chagrin.

-dave

This is not a sig. This is a duck. Quack.

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Hi Again,

 

Ok, below is a paragraph from a January 1992 Kitplanes article called Birth Of An Eagle Part 1 pg 17. This is what led me to my question back in post #58.

 

The wings are so similar to those of a Long-EZ that a pair of Long-EZ wings could be bolted onto the Berkut without modification (though it's not recommended). The greatest difference is in a carefully generated airfoil section. Ronneberg found that the Eppler airfoil presented in the original plans had been slightly corrupted in the printing process, so new templates were made from all-new plottings.

 

Soooo we would probably have to talk to Dave to get the real scoop. Maybe it was just a selling tactic. I was just curious if anyone had heard of this before.

 

Bob

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I was just curious if anyone had heard of this before.

Without seeing Burt's original master drawings, I don't think there's any way to positively know what the airfoil was supposed to look like. I've done some pretty careful analysis of the printing distortion from the templates I have access to, and the changes are decidedly minimal from what I believe is the original master, but without an accurate master to compare it to, I'm guessing.

 

Dave R. may have had access to more than I do, so I can't reliably refute that claim, not do I want to. :D

 

Does anyone have an accurate drawing of the Berkut wing profile that they could share for comparison? I'm only asking out of curiosity. I don't want to build a Berkut, but I am curious to get to the bottom of this. Any profile will do, as long as I can match it up to one of the templates I have.

 

-dave

This is not a sig. This is a duck. Quack.

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dpaton said:

Does anyone have an accurate drawing of the Berkut wing profile that they could share for comparison?

Sure... download the Open-EZ drawings. I seriously doubt that Berkut airfoil drawings/templates ever existed outside of the Berkut factory. Why would they?

Kitplanes, Jan. 1992 p.17 said:

Ronneberg found that the Eppler airfoil presented in the original plans had been slightly corrupted in the printing process, so new templates were made from all-new plottings.

Sounds exactly like what Dave (dpaton) is doing here.

Hookr55 said:

Maybe it was just a selling tactic.

I'm sure there was some value in cleaning up the drawings, but it wasn't to change the airfoil. That whole mention is more a sales tactic than anything to me.

For me, there's no point in digging into the Berkut airfoil any further, since it's the same as the Long-EZ airfoil. All the Berkut was (not to trivialize it or comparable design modifications), was a longer and wider Long-EZ made with a lot of carbon fiber. Throw a Lycoming 360 or 540 in and you're sure to go fast.

Jon Matcho :busy:
Builder & Canard Zone Admin
Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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velocity dreamer said:

has anyone looked at the link I inserted to post 59? Just wondering if anyone agrees with this report and if so how could we use it to our advantage.

Yes, I read it. There's nothing new in it, except the student's lack of understanding of the fundamentals of lift. Actually, I guess that's not new - most people don't understand how Newton, Bernoulli, and/or Coanda play into the concept of lift. Mostly they don't understand that Coanda has nothing to do with lift production on a normal wing, and that Bernoulli and Newton are two different ways of saying EXACTLY the same thing.

At any rate, from the standpoint of the canard downwash effecting the AOA of the main wing, this is also no surprise, and is taken into account in ALL aircraft design, whether canard or conventional - the downwash from the front wing can ALWAYS affect the AOA of the rear wing.

While the paper is a nice science experiment, the student understands and admits that because the Reynolds number of the small model is very small, the results can not necessarily be extended to full size canard aircraft, at least with respect to the magnitude or angles at which the effect occurred.

How's that?

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