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ColinB

Would there be a market for a betkut esq molded kit ?

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Hey Lynn it can be done, they do glider composite wings in two days. But they use molds and the guys that work on them are very fast. You got to love those German.

 

But I don't know about the Berkut of Ez wing....

i don't doubt that it can be done with a full crew of experienced people. but the glider wing is engineered to be built that way and the ez wing is not. so i doubt anyone can re-engineer the ez wing, build molds, build a spar and wing skins and assemble it in a few days. assemble it in a few days, Yes and all the other work required did not count because it was done in your free time?

Evolultion Eze RG -a two place side by side-200 Knots on 200 HP. A&P / pilot for over 30 years

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I have been watching this thread and there is a lot of what we do wraped up in this discussion. Berkut tried it and to some degree was successful. Stan Montgomery tried it with mixed results. Perhaps one should look at the pros and cons of making a molded aircraft and optimize the con side. If one started the effort with the fuselage and for the moment concentrate on it learning along the way it may work. Modularize the fuselage by designing it for 4 or 2 place. Integrate the strakes into the fuse so that they cannot leak. If enough builders are polled to determine what steps required more effort than others than the design could save builders time. That is where Vans design shines, it goes together quickly. Exploit the advantages of composite techniques. If the trade study indicates that there is a tendency for customers to want to change things in the design then what you offer has to be able to still survive the design change and not cause the creation of an unsafe A/C. This is why designers want their customer to build to the plans. After your analysis you may decided to start on a different part like carbon fiber ailerons. Keep thinking.

 

Joe Berki

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i don't doubt that it can be done with a full crew of experienced people. but the glider wing is engineered to be built that way and the ez wing is not. so i doubt anyone can re-engineer the ez wing, build molds, build a spar and wing skins and assemble it in a few days. assemble it in a few days, Yes and all the other work required did not count because it was done in your free time?

 

You are absolutely right.

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anyway as they say the proof is in the pudding,

Actually, the saying is: "the proof of the pudding is in the eating". The above commonly misquoted statement doesn't make any sense.

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Actually, the saying is: "the proof of the pudding is in the eating". The above commonly misquoted statement doesn't make any sense.

Unless, of course, I've got test coins in my pudding. Then it would be a complaint, though, I'd think.

 

At least there is one other person on the face of the earth that knows what this saying is, and what it means. Thank you. One wonders how the saying ever came into existence with no one understanding it.

 

Proof: the act of testing or making trial of anything; test; trial: to put a thing to the proof.

 

On the other hand, most americans subscribe to Humpty Dumpty's dictum:

 

“When I use a word," Humpty Dumpty said in rather a scornful tone, "it means just what I choose it to mean - neither more nor less.”

 

Steve, we're fighting a losing battle.

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i don't doubt that it can be done with a full crew of experienced people. but the glider wing is engineered to be built that way and the ez wing is not. so i doubt anyone can re-engineer the ez wing, build molds, build a spar and wing skins and assemble it in a few days. assemble it in a few days, Yes and all the other work required did not count because it was done in your free time?

 

actually all i said was the wing patterns could be machined and molded in a few days

 

i never said anything about re-engineering, or even making the wings in that example

 

also completely re-engineering it isnt necessary if a foam core is used, as the construction will actually be very similar, just think of it as having your existing foam core, then laminating your sparcaps and outerskins in one operation, then enclosing it between 2 wing shaped molds and squeezing it around the core with a hundred or so tons of pressure and heating to cure, causing the outside to be the exact shape of the wing without need for sanding and floxing to get it smooth

 

and if in the future i do want to try build a ribbed wing the existing molds do not require altering either as the outside shape is unaltered

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actually all i said was the wing patterns could be machined and molded in a few days

 

i never said anything about re-engineering, or even making the wings in that example

 

also completely re-engineering it isnt necessary if a foam core is used, as the construction will actually be very similar, just think of it as having your existing foam core, then laminating your sparcaps and outerskins in one operation, then enclosing it between 2 wing shaped molds and squeezing it around the core with a hundred or so tons of pressure and heating to cure, causing the outside to be the exact shape of the wing without need for sanding and floxing to get it smooth

 

and if in the future i do want to try build a ribbed wing the existing molds do not require altering either as the outside shape is unaltered

I am not trying to discourage you from building or thinking of a new way to build a plane but,

I don't think you totally under stand the complexity of the wing as designed for the long or cozy. the wing skin is not just a few layers of glass and the internals of the wing are not just a foam block shaped like a wing. the wing spar is made up of many layups using the male foam blanks as a core. the wing skin is made up of several layups that include the the skins, the attach reinforcements and layers to hold on the winglets. if you mold the wing skin and then install the reinforcements and the winglets attach layups on the outside of your molded part you will still have to refill about half of the wing to get a finished wing. if you do mold the wing skins and put the extra layups for the winglets on the inside of the wing skin then the wing would need to be made with the winglets as part of the wing, all one piece. however you do it if it is not done to the plans then it is a different wing structure, would need to be engineered for that type of construction and tested to destruction to prove it is safe to fly. there is a big difference between the F1 parts you are building and the aircraft structure. if an F1 part fails you pull over and let the race winner pass. if an aircraft structure fails you will be the one that is doing the passing.


Evolultion Eze RG -a two place side by side-200 Knots on 200 HP. A&P / pilot for over 30 years

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I agree with Lynn on this one.

(as Jason would say 'Waitress!')

 

Having never built a canard airplane, you are never going to get it.

If you read a bit on how Dave came up with the Berkut, you may start to get some understanding of how to get there. He built his plane, cut it up, and tossed it. Anytime you change the process, you need a full understanding of the current process first. Not everything you know will translate to this application.

 

If I was going to mold and autoclave anything, I would start with the Center Section Spar. Many believe it should be constructed very early in the process to give it as much cure time as possible prior to hanging wings on it. If it was autoclaved, so much the better.

 

As far as the main wing and canard, our foam will not stand the high heat values of an autoclave.

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actually the center spa is the first thing that will be built via autoclave

 

 

also yes you are correct about your foams not being upto clave temps if you read back to some of my posts i explained i will be using a different foam (rohacell) with the same density as the one you use

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For thoughts interested in this subject go to this web link on the Burkut.

http://www.canardzone.com/forum/showthread.php?t=2960&page=8

This post was a year and some time ago. The project is a little farther along.

I wish I could have used A cnc to do the plugs. Time not money was on my side. Be sides it was something to do. I really enjoy all you posts.

Best to all

Bob

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actually the center spa is the first thing that will be built via autoclave

 

 

also yes you are correct about your foams not being upto clave temps if you read back to some of my posts i explained i will be using a different foam (rohacell) with the same density as the one you use

before you can build a spar separate from the wing you will need dimensions and the plans do not have dimensions for the spar directly. you may be able to derive at the dimensions by doing a full size layout. by the time you do all that you could have cut out the wing foam and had it glassed. also the wing templates are not lined up with the butt lines directly so there will be some work to be done there. the templates are also a bit over size to account for the material consumed in the hot wire process. the outboard templates also are thinner then the true airfoil to allow for the extra plys that hold on the winglets. but you already know all this because you have a set of the plans and have studied them. right

 

if you do change the type of foam you will be flying an untested wing that you don't how it will act in the air. but you will be doing flutter analysis on the wing before you fly it. right. there is a plane that was built with a "better foam" and that airplane was falling apart and delaminating and was to cut up into pieces before it killed someone.


Evolultion Eze RG -a two place side by side-200 Knots on 200 HP. A&P / pilot for over 30 years

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but you already know all this because you have a set of the plans and have studied them. right

No, but i have seen a few pictures of an ez and it looks very pretty :P

 

you know constructive comments are always welcomed, however there is no need to be so condescending

 

if you do change the type of foam you will be flying an untested wing that you don't how it will act in the air. but you will be doing flutter analysis on the wing before you fly it. right. there is a plane that was built with a "better foam" and that airplane was falling apart and delaminating and was to cut up into pieces before it killed someone.

And how exactly do you think the flutter will change at all? the core is of the same density, its just capable of handling a higher heat, will the flutter calculations take in to consideration the colour of the core material too?

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ColinB

 

Here is a Reality Check you should look at:

 

http://members.iquest.net/~aca/index.htm

 

Nice work, which he displayed last year at Oshkosh.

 

But it has taken him Y-E-A-R-S to get this far along.

 

And the Corvette Engine it is based upon may now

vanish under the new "Government Motors"...........

 

Then look at www.wingco.com..........

 

JP

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ColinB

 

Here is a Reality Check you should look at:

 

http://members.iquest.net/~aca/index.htm

 

Nice work, which he displayed last year at Oshkosh.

 

But it has taken him Y-E-A-R-S to get this far along.

 

And the Corvette Engine it is based upon may now

vanish under the new "Government Motors"...........

 

Then look at www.wingco.com..........

 

JP

I like the way he says he will work all the bugs out before he sells any parts, yet he is offering the kit for sale even before it has flown. building his own prop is a waste of effort if he ever plans to finish. where do we sign up for the test pilot seat? New airframe design, retracts, carbon gear box, his own prop and auto engine conversion all done in one test bed, all built by a guy that has no aircraft experience. just because a guy can make pretty carbon parts does not mean it will fly.

 

and the wingco it had one major flaw, it could almost fly


Evolultion Eze RG -a two place side by side-200 Knots on 200 HP. A&P / pilot for over 30 years

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> there is a plane that was built with a "better foam" and that airplane was

> falling apart and delaminating and was to cut up into pieces before it killed

> someone.

 

I assume that was built with polyurethane insulation foam. Which ages and converts to dust after being subjected to vibrations after a few years.

Rohacell, in case you don't know that material yet (don't blame you, it has only become available in the US in the last few years), does not show that behavior. It has a great track record being used in trains, transportation, race cars, aviation and space applications (Delta, Ariane, Boeing, Airbus, rotor blades for helicopters and wind energy...). It's not quite the same as flotation billet or roof insulation foam.

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Rohacell, in case you don't know that material yet (don't blame you, it has only become available in the US in the last few years), does not show that behavior. It has a great track record being used in trains, transportation, race cars, aviation and space applications (Delta, Ariane, Boeing, Airbus, rotor blades for helicopters and wind energy...). It's not quite the same as flotation billet or roof insulation foam.

I would not imagine it works the same when it comes time to hotwire it.

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That Algae thing is pretty damn cool looking. Will be nice to see if he can make it fly successfully.

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I would not imagine it works the same when it comes time to hotwire it.

Hotwiring Rohacell?

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Hotwiring Rohacell?

Yes ..... from what I read it's both pricey and would require a different approach to shaping/machining compared to our construction techniques.

 

Might as well eliminate the EZ/Eze designation from the model name.

What made scaled a reality was the ability of the Rutan operation to quickly create a scaled version of a fullsize design to provide proof of concept data.

 

This all sounds real interesting and I applaud anyone who is extending their knowledge base in these areas.

Downside is you will not be seeing them at Rough River for many years ......... if ever.

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Rohacell is made out of a plastic in same family as Kapton / Polyimide.

 

That's the stuff they make flexible printed circuit boards out of.

 

Does not melt with a soldering iron, so forget about hot wiring.

 

It is hard and tough, but not brittle, CNC's very nicely.

 

Survives high pressure - high temperature autoclave cure.

 

But somewhat costly.............

 

JCP

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Yes ..... from what I read it's both pricey and would require a different approach to shaping/machining compared to our construction techniques.

It's a completly different material, much more expensive, prices here http://www.cstsales.com/core_materials-ss3.html, definitely not suitable for hotwiring nor for solid aplications like blue foam. You might want to visit Homebuilt from time to time, you will find there some threads about a different type of materials, foams, resins, etc.

 

 

This all sounds real interesting and I applaud anyone who is extending their knowledge base in these areas.

Downside is you will not be seeing them at Rough River for many years ......... if ever.

I don't agree with you, it's much easier than 20 or 30 years ago, (with modern technology and unlimited money), everything what you need is a complete 3D Cad model of entire plane, professional tools can speed up your work.

 

Here is a short example

Of course these machines can work not only in clay.

 

Seb

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I don't agree with you, it's much easier than 20 or 30 years ago, (with modern technology and unlimited money), everything what you need is a complete 3D Cad model of entire plane, professional tools can speed up your work.

 

Okay ....... I'll watch for that.

 

In my shop it's all about application not theory.

I don't have that 'unlimited money' you mentioned.

If we could cash in on all the technologies that exist, we would be driving fuel cell cars and all kinds of neat stuf ......... but that won't get me to work today.

 

I can't fly a theory so all of that will have to wait. :D

I guess that's one of the reasons I went with the plans built vs. a kit. Good discussion just the same.

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In my shop it's all about application not theory..

It's not theory, most companies use these methods in this or other way, ask Marc how they make molds at Scaled. Machines are also more precisely and faster than humans.

I don't have that 'unlimited money' you mentioned.

I was thinking rather about Colin, if he has free access to all these machines why not to use them. But for single project it's definitely not the best idea, one of the HBA members said that the price for CNC machined tool (mold) is about 200$ per square foot (if I remember correctly), multiply it by your plane surface area, now you know what type of money we are talking about.

 

 

Seb

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