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Some CAD surfaces


Justin

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Hello EZ people,

I made some surfaces from Open EZ data I downloaded ages ago. 'Thought I would share them.

I am going further with the modeling, making a sleeker canopy, and a slightly less drooped nose, along with packaging the UL390i engine. It is almost as heavy as the O-235, is slightly smaller, very likely less expensive, fuel injected, and has FADEC. I will add a few WIP pictures.

Cheers,

Justin

ps I think there is a file size limit on uploading images. I tried some just over 3mb and they failed.

ez70.png

ez71.png

OpenEZ.zip

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Nice work!  What tools do you use to make all that happen?

16 hours ago, Justin said:

I think there is a file size limit on uploading images. I tried some just over 3mb and they failed.

I'll take a look at that to see how to increase without going breaking the bank 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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Hi Jon,

I use Rhino for surface lofting, and a combination of Rhino and Catia for detail and assembly work. Catia renders pictures well enough for me, and is fairly quick at it.

I don't know if I will build an EZ, but was helping with some modifications on another one, and just continued modelling.

 

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Hi Jeff,

Well, it started when someone sent me another CAD model to help them with a modification. There were errors when compared to the Rutan drawings that were on the Open EZ site. Both the IP and the little frame (F28, I think) just aft of the canard were in the wrong position. I have all the CP publications from somewhere, probably Open EZ too. Ary Glantz kindly pointed me to some info to correct some of the scaling issues in the drawings.

Can anyone tell me, is there anything pertinent to the Long EZ on the TERF CD that is not in the Open EZ information ? I have not found much information on the main gear legs.

Cheers,

Justin

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15 hours ago, Justin said:

Ary Glantz kindly pointed me to some info to correct some of the scaling issues in the drawings.

Justin, Ary is mistaken in that there are NO scaling issues with the drawings as you can see from this explanation:  https://www.canardzone.com/forums/topic/20540-important-update-regarding-open-ez-rev-5-templates

 

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 Jon,

Ary linked the very same page to me. Sheets A2, A7 and A10 are shown with scaling errors. It easy to cross check in CAD, because you overlay the drawings on the stations, waterplanes and but lines that are dimensioned by RAF. What is difficult to know is which axis on A2, A7 and A10 is incorrect, but the information in the linked page clarifies this.  I am sure this is all Ary did his in Catia. I use Rhino for this kind of correction; sometimes even in Spitfire work I do.

3.png

LOCKinAC-1.jpg

Spitfront3.png

UC50.png

Edited by Justin
just added a few words
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Justin, that's nice work!  How did you acquire and maintain those skills?

6 hours ago, Justin said:

What is difficult to know is which axis on A2, A7 and A10 is incorrect, but the information in the linked page clarifies this.

Yes, which is why I pointed Ary to that page as soon as I learned of what he was doing.  The simple answer would have been this:

  1. Download and print the Open-EZ drawings.
  2. Make the corrections shown in red on 3 sheets.
  3. Follow the instructions.

Ary just went overboard for no additional value to these steps (although I see nothing wrong with what he did).

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

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On 5/7/2020 at 2:24 PM, Justin said:

I think there is a file size limit on uploading images. I tried some just over 3mb and they failed.

Interesting.  I verified the limit per post is set to be 50MB.  Let me know if you have any issues and I'll be happy to review.

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 Jon,

Thanks for your replies.

Skills?.... I am an automotive designer with aerospace and defence industry experience. I have been using CAD since 1980. I am afraid I am impaired in some way.... I just cannot leave 3D geometric challenges alone, and end up in all sorts of projects. I also design boats, mainly sailing craft. There are about 100 boats afloat today that I have designed. The Spitfire work started in a purely geometric wing lofting challenge I fell into, but now I help a little on a restoration project over here,

Well, I have latched on to Open EZ now. I am considering building a Sonex B. A long range touring aircraft could be quite a good thing for me. I like working with epoxy and glass, and an EZ is pretty unmatched when it comes to long range, speed and economy. I am an ex-glider pilot, and really like being in the front on any tandem seater, with very good fields of view.

I will probably model an EZ in X-Plane 11,  if I can find accurate airfoil performance curves.

I did ask a question in an earlier post on this thread.... Is there really anything more on the TERF CD. than already published in Open EZ, and all the CP publications, pertinent to the EZ build? It is the only Rutan aircraft I will find time to play with, although the Q1 is quite fascinating.

I will try attaching a high resolution rendering now.... Nope.. it didn't work. It was only a 3.3Mb PNG file.

Cheers,

Justin

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50 minutes ago, Justin said:

Is there really anything more on the TERF CD. than already published in Open EZ, and all the CP publications, pertinent to the EZ build?

Yes.  Here's a better break-down:

  • Plans
    • You can get a copy of anyone's plans.  RAF used to refer to these as "Xerox EZs".
    • You can acquire the TERF CD.
    • The Open-EZ does not yet include actual plan text.
  • Drawings
    • These were originally provided in printed form, to scale, from RAF as part of Long-EZ plans.
    • The Open-EZ drawings are these.
    • The TERF CD does not include scale drawings.
  • Canard Pusher Newsletters
    • These contain all the plans changes while RAF was in business.

You need to question how someone else came to the CAD model that was sent to you.  To so so, they'd have to account for all of the above.  For example, the Open-EZ drawings allow you to define the airfoil shape, but do not provide you with information on how many layers of fiberglass are to be used to cover them, and for the winglets, the angles they are to be canted inward.  

I am always concerned about seeing things in 3D CAD where the typical reaction immediately seems to be "oh that's better than anything", but it's just not if the translation from the original source is flawed or in any way.

Make sense?

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 Jon.

Yeah. ´Makes good sense. CAD stuff can be presented as impressive even when it is complete rubbish. Crap in = Crap out. We see it too often in my day job.  It is just good sense to be suspicious of it. With old, manually drawn projects, what CAD can do is fill in gaps, where the 'power of the pencil' gets away with ridiculous inaccuracy, or some error has been made, or there is simply missing data. I have to say that my view of RAF drawings is that they are pretty dismal, but good enough for skilled people to make perfectly good aircraft.

The 3D models I received were treated with my normal suspicion, and failed. I am using data now from Open EZ, and I suspect there is little worth having the CD from TERF. I hope that provokes some informative responses that might change my view.

One discrepancy I have found more recently is that the RAF drawing of the centre spar, when modelled in 3D, goes slightly through the internal wing core skins, as modelled from the Open EZ drawing scans. It is a small amount, but notable. The RAF drawing of the centre spar makes some approximations of the lofted wing skin inside surface. I know there was no CAD lofting when Long EZ was made, but you don't see so much error in Spitfire drawings from the 1930s.

As far as I have explored the Canard Pusher newsletters now, there seems to be good laminate build data there, so laminate thicknesses can be determined. There are an awful lot of CP newsletters, and I have a lot more to learn from exploring them.

Cheers,

Justin

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