Moldless Copmposite Construction?

[gofastclint]

Aircraft like the Arnold AR-5 and many canard style planes are built using "Moldless Composite Construction"

 

Does any one know of a site that features details of how to implement this technique to build aircraft, with good picture, starting from a foam blank?

 

 

[youngmic]

Other than a google search I don't know of one.

 

However you could try buying a set of plans for a Vari-eze or Long-ez to see what was applicable to those designs. (EBay)

 

To attempt to build any sort of one off performance machine without detailed knowledge of this type of construction could be a daunting task.

 

In essence it is quite simple, sort of like building a surf board, but without knowing what type of material and how much and in what place it might be difficult to obtain a strong and light construction.

 

The Vari-eze wing for example is cut from a single block of foam then the outer half is cut off and put aside while the inboard half has the fore and aft section cut off leaving a ~6" square centre section which is shaved to a taper top and bottom, deeper to the inboard.

 

This tapered centre ~6" section is then wrapped in glass which forms the shear web. Then the fore and aft sections are flocked back on as is the outer half. You then have a foam section of a wing with a tappered inner ~6" section which you lay up the spar in. This is a large triangulated pre (?) wet glass, layered napkin style in the tappered section, back and forth until you have a spar cap with multiple layers which fill the taper back to profile and reducing in layers/thickness to the outboard end of the spar, being half span. The whole wing is then wrapped in several layers of BID and UNI glass, then profiled with micro and waa laa you have a wing (perhaps).

 

Or as history will have proved for some, a month of your life you will never get back and a sticky mess which know one can seem to recognise.

 

If done right you will have very light and strong wing, when I remove the wing (Vari-eze) for inspection I always cringe a little on just how light the damn thing is, feels like about 25Kg.

 

The fuse is basically bulkheads attached to longerons infilled with foam then glassed.

 

The attach points on the wing are alloy components which are incorporated in the intial layup of the spar. A one piece wing might be an easier proposition?

 

A salient comment from Burt Rutan to a builder way back when at one of the builder workshops, when the builder pointed out he had improved the design by using carbon or an extra layup? for added stiffness was; "congratulations you have built a 3g wing". (about half the original) It would appear that real engineering and maths had been used to design the original.

 

Hope that gives a little insight.

 

Mick

 

 

[gofastclint]

Thanks alot, I'm going to go through the Vari-Eze sites on the net. I am also going to buy the Arnold AR-5 construction dvd's, I find it so amazing that he broke the 1 square foot drag factor.

 

 

[Yenn]

Have a look at HomeBuiltAirplanes.com - Experimental Aircraft Discussion forums cover a multitude of different methods and you can join up and ask all the questions you want.

 

 

[Adrian Lewer]

LOL the Mate in question who is building the Rand KR-2S Has just sold his long-eze,. done a bit of flying in her, Lycoming 300 or something is definitely a VH machine. Cruise at 155 Kts. Mongrel to build. a retired man built my mates in Frankston and it took him 10 years. He was to busy flying the Long-EzE hence the near stop on the KR-2S. (he is actually building the Rand KR-2S but narrowed down for single seat use) Pics are coming.

 

 

[gofastclint]

HomeBuiltAirplanes.com - Experimental Aircraft Discussion[/url] forums cover a multitude of different methods and you can join up and ask all the questions you want.

already a member, what a top site. i like to watch video or see pictures more so than read as I am a member of DNA, national dyslexia association. pun intended.

 

 

[youngmic]

The AR 5 is certainly something else, quite amazing levels of laminar flow achieved on both wings and fuse. His insight into area rule I suspect, along with attention to detail resulted in some fantastic numbers.

 

 

[gofastclint]

The AR 5 is certainly something else, quite amazing levels of laminar flow achieved on both wings and fuse. His insight into area rule I suspect, along with attention to detail resulted in some fantastic numbers.

and as for the AR-6, imagine a larger scale, still 1 seater with a 3300 jab.

 

 

[youngmic]

and as for the AR-6, imagine a larger scale, still 1 seater with a 3300 jab.

Aside from losing the pleasure (???) of building it, an easy and cheap go fast yee haa machine could be the Cassutt racer that seems to pop in and out of the Trader. Flog the O-200 out of it and replace it with a dimensionally smaller (less drag) and more HP 3300.

Shoud see around the 180kts. There is probably numerous other interesting go hard Formula 1 Reno machines kicking around the US. Maybe the Nemisis design is worth a look.

 

There is always the risk that by supersizing the AR 5 the weight/structure ratio deteriorates along with a reynolds number increase and loss of laminar flow.

 

Still your idea sounds interesting.

 

M