Cheap 2 seater anyone?

[Head in the clouds]

Hey HITC, when you say bonded aluminium do you mean on to foam as in the wings or is the skin glued to aluminium ribs and fuse formers? Do you still have plans for the Macro as Ive tried to google it with little success so far.

The first Macro had Klegecell closed cell rigid PVC foam ribs and the aly skin was bonded to that, the later ones had all aly ribs and they all had angle aly fuselage trusses with everything bonded using Permabond F241 structural acrylic adhesive (as used by Boeing, these days it's called Permabond TA4246).

 

I never drew plans beyond a single sheet, I had templates for everything but I didn't keep anything because they were so very simple that it would be easy enough to re-create if I ever wanted to. In the mid 1980s the regulations were expected to lighten up from the draconian original issue but although they did somewhat, the Macros still didn't comply so I abandoned the project and went on to single seat Cub lookalikes.

 

There isn't much on the net about them because the www didn't exist back then but there is a mention of one being registered by someone in 1987 when it was about 3 yrs old - 7th one down http://www.nor-raaus.com.au/admin/aircraft_database_registration.html

 

It also featured in Berger-Burr's 'Ultralight and Microlight Aircraft of the World', there's an extract here ...well there used to be, on virtual ultralight museum but something's happened to the site, I'll post it later if I find a new link that works.

 

 

[Head in the clouds]

One of the good things about my tornado. I needed to replace the scratched and cracked screens. 2mm x 2400mm x 1200mm polycarbonate delivered for $120. A couple of hours work cutting the new screens using the old screens as a template and I can rivet them back on.That' a fraction of the cost of a blown Perspex canopy.

Polycarbonate is quite a good screen material and I use it a lot where the design caters for a flatwrap screen, but I'm not so sure about the economy of it over the lifespan of an aircraft because you may need to replace it quite a few times. One of its main benefits is that it's very good in event of a birdstrike because it won't shatter.

 

The disadvantages of polycarb sheeting are many - you can't polish scratches out, if you try it leaves a semi-opaque area, spill fuel on it anywhere where it's curved and it cracks up instantly, you can't put Rainex water repellant on it for the same reason, it yellows with age and UV exposure, you can't bond it effectively to seal around the edges and it cracks from the rivet holes unless you're very lucky even if you oversize the holes and use inserts to prevent clamping.

 

Blown canopies are very easy to make, there are plenty of people in most cities who have ovens for heating the acrylic sheet (or you can make one for $100 or so) and it isn't difficult to make the edge frame. Then all you need is a support stand to support the frame upside down so that the canopy droops below it, and compressed air. It's certainly better if you're making a dozen than a one off though...

 

The beauty of blown canopies is their clarity, compound curvature strength (eggshell structure?), easily polish out scratches, good with Rainex, not affected by fuel or cleaning alcohols etc

 

 

[fly_tornado]

This poly carbonate is UV2 Bayer offer a 10 yr warranty

 

 

[Head in the clouds]

This poly carbonate is UV2 Bayer offer a 10 yr warranty

Yeah, I use Makrolon too, or Lexan but try claiming from their warranty when it fails after you used it curved, on an aircraft, and spilled fuel on it... The UV aspect is minor compared to all its other failure modes unfortunately.

 

 

[planet47]

FT

 

 

[fly_tornado]

HIC, I would like to see how you make a blown canopy cheaply. From what I understand, getting the shape right and a uniform thickness takes years of practice.

 

 

[fly_tornado]

You can polish/clean polycarbonate. A polishing compound for swirl removal available from auto parts shops will remove that layer of gunk. Polycarbonate is hygroscopic so it absorbs moisture from the air, the dirty sheen you see on polycarbonate is dirt drawn into the surface by moisture. Polishing with swirl remover will clear it up to almost new condition.

 

 

[Head in the clouds]

HIC, I would like to see how you make a blown canopy cheaply. From what I understand, getting the shape right and a uniform thickness takes years of practice.

No, no practice (or years of experience) required, it's very easy but does help if you go and watch someone else do it first. Domes are blown upright, canopies upside down. You need to make a good frame to the shape of the eventual canopy frame, both halves, inside and out, and also the bottom seal frame, so you can clamp them together with the cast acrylic sheet between them. You heat the acrylic to 375 IIRC, drape it over the inner frame, clamp the outer frame to the inner, invert the assembly and blow compressed air through the bottom seal frame.

 

If you want to get extra clever, with practice you can add additional heat from a radiant source or heated compressed air from the outside while it's still pressurised to create bulges. Before you begin you need to cut templates to hold against the profile to determine when it is sufficiently inflated. If you want more working time pre-heat the internal compressed air.

 

I learnt it all in a day from a bloke who blew glider canopies down at Tocumwal, then made four for my own projects and since then have made several for hydroplane racers and also for the solar car racers in Darwin and one for a Midget Mustang, one for a bloke's sidecar...

 

Here's a vid that gives you the general idea.

 

 

I've cleaned plenty of polycarbonate in my time and never got it anywhere near like new but I'm not against it, it's tough and convenient and easy to replace.

 

 

[fly_tornado]

So how do I cut the white protective membrane on the makrolon without leaving a mark on the polycarbonate?

 

 

[Head in the clouds]

So how do I cut the white protective membrane on the makrolon without leaving a mark on the polycarbonate?

If you mean around the edges so that you can rivet it on while leaving the majority covered until it's all installed what I do is peel the plastic film back all around the edges by an inch or so and fold it back on itself then lay a stanley blade flat on the sheet and run it around the folded over film, letter-opener fashion. Or just leave it folded back so you have something to get hold off when you want to peel the rest off.

 

 

[fly_tornado]

Ok thanks that sounds like a plan

 

 

[Head in the clouds]

Finally I have the configuration sorted so that the CG is sufficiently unaffected by fuel and crew weight variations and still have a useful baggage allowance. To achieve that I had to get rid of all stagger between the wings and then had a fair job to get some pleasing looks back again but it did provide a great advantage in terms of allowing for much larger doors and making it easier to get in and out. And the empennage length is now right for folding the stab to the outside of the N frame.

 

I also had to get the stab/elevator and fin/rudder volume sufficient for the low minimum controllable speeds I'm chasing. So apart from setting the decalage (upper and lower wing incidence difference) to get a very gentle and progressive stall, I'm pretty well ready to start roughing out the internal structure.

 

Here's a sneak preview, tell me what you think -

 

 

 

 

 

 

 

 

[DGL Fox]

Looking good so far mate...

 

David

 

 

[fly_tornado]

I was hoping for something a bit sexier

 

 

[Teckair]

Good concept.

 

 

[M61A1]

Looks like a cross between an X-Air and Bill Knight's Amethyst Falcon.

 

 

[ave8rr]

Waiting for the prototype Alan. Keep up the good work.

 

 

[Guernsey]

Just add a tail wheel and it becomes an aircraft for everyone:-

 

Tail dragger,

 

Nose wheel.

 

High wing.

 

Low wing.

 

Biplane.

 

Fully enclosed.

 

Seriously though, I believe it is a great concept.

 

Alan.

 

 

[howe]

Alan as a single seat 95.10 a few of us fly kestrels, it lives in the trailer.

 

As a two place what about the NZ Bantam B22 S fits most criteria.

 

 

 

[Marty_d]

I just found this thread again after a few months, love it.

 

However....

 

I would prefer a designer of most ugly planes. This would have to be chris heintz from zenair.Functional designs but only a mother could love the look. And yes i owned a zodiac once.

I will now run and hide.

grrrr...

 

I like the look of the 701 (or Savannah, given it looks pretty much identical) in the same way I like the look of the Landrover Defender. "Chunky and angular but functional as all hell" can have its own attractiveness in vehicles...

 

HITC, love the photoshopped SR-71. Your work?

 

Also love the biplane design. Fantastic stuff.

 

 

[M61A1]

I just found this thread again after a few months, love it.However....

 

grrrr...

 

I like the look of the 701 (or Savannah, given it looks pretty much identical) in the same way I like the look of the Landrover Defender. "Chunky and angular but functional as all hell" can have its own attractiveness in vehicles...

 

HITC, love the photoshopped SR-71. Your work?

 

Also love the biplane design. Fantastic stuff.

I love functional.....meaning that it looks like it does because it had to look that way to do what it does. eg: F4U and F4.

 

 

[fly_tornado]

Finished cutting my tornado screens tonight. about 4 hours work. still need to sand the edges smooth, drill, cleco and install 150 odd rivets and I am done. once I finish repainting the frames

 

 

[Head in the clouds]

Alan as a single seat 95.10 a few of us fly kestrels, it lives in the trailer.As a two place what about the NZ Bantam B22 S fits most criteria.

Yes, the Kestrel is a great little plane, Cec Lea design IIRC, and has all the good aspects of the late model Thrusters. And the Bantam is also good, perhaps not the prettiest... but very functional.

 

The only reason I didn't go that way is that the biplane is a much smaller package but still has the same low wing-loading. Being of small span and short when the tail is folded there's no need to remove the wings for trailer storage or transport. And it folds so much easier and quicker, with one person, than removing the wings.

 

The tri-gear is a necessity for the AirToy biplane, so that it still sits on its gear when folded, and although I'd prefer a dragger it looks like the future up and coming flyers will all train on tri-gear so that's the way of the future market I guess.

 

I just found this thread again after a few months, love it.However....

 

grrrr...

 

I like the look of the 701 (or Savannah, given it looks pretty much identical) in the same way I like the look of the Landrover Defender. "Chunky and angular but functional as all hell" can have its own attractiveness in vehicles...

 

HITC, love the photoshopped SR-71. Your work?

 

Also love the biplane design. Fantastic stuff.

Glad you're enjoying the thread Marty, me too. And thanks for the encouragement about the biplane.

 

I didn't photoshop the SR71, as I understand it someone in the US built it, it has a pair of 0-200s in it I think.

 

I love functional.....meaning that it looks like it does because it had to look that way to do what it does. eg: F4U and F4.

Yup, form follows function, that's why the AirToy is as it is, there's no other way it could be and still fulfill the spec.

 

Looks like a cross between an X-Air and Bill Knight's Amethyst Falcon.

Actually I was just a tad miffed when I first read this, and I might add that I have a high admiration for your posts, (I really like your comments in the 'Losing our Heritage thread' BTW) but now that I think about it I couldn't agree more and there's not much wrong with that pedigree-cross, add tri-gear and that's just about it. The structure is quite different though.

 

Waiting for the prototype Alan. Keep up the good work.

Thanks Mike. And talking of the prototype well in advance, does anyone have shed space in SEQld where it could be assembled? Anyone want to assemble it? Part own it? Just knocking around ideas at this stage. My problem is that OzMoz is still under way and taking up all my workspace.

 

 

[Marty_d]

I didn't photoshop the SR71, as I understand it someone in the US built it, it has a pair of 0-200s in it I think.

Nope - definitely a fake. If you look at the photo closely you can see that the SR-71 and its shadow have been pasted (very cleverly) onto the concrete background. Some propeller blades have been pasted onto the inlet cone (funny how they don't cast a shadow!) and then the lad in the overalls pasted on. If you check out the shadows of his legs, they appear to end around knee height...

Plus, there must be 2 suns in that sky, as the bloke has the light on the side of his face, but the aircraft's shadow is right below it...

 

(Yes I looked at this for way too long!!)

 

 

[Head in the clouds]

Nope - definitely a fake....

I see what you're getting at but I'm not convinced. That is not a picture of a full-sized Blackbird, nothing like it - see the picture of the real one below, and note the cockpit(s)/windshield(s) size in relation to the rest.

 

I can't find anything about it now but I seem to remember reading about the building of this semi-scale replica, I thought the builder was an ex-Lockheed engineer. I might have dreamt it though!