CHEAP DIY ULTRALIGHTS? FAIR DINKUM.

[onetrack]

Mickeymax could always build a Heath Parasol. Proven design, lightweight, low cost - and there's a good choice of small, powerful engines available today.

 

Then, he'd always have the fun factor, on the ground, of people coming up in droves, and wanting to know all about it!

 

Aviation Heritage Golden Age Short Stories

 

1931 Heath LNB-4 Parasol - N953M

 

 

 

[facthunter]

The Heath Parasol is one of the best ever designs from a simplicity and practical view point.. Nev

 

 

[bexrbetter]

That's why the only retrofit bolt on redrives I know of that are sold are gearboxes, and they're not cheap.

There are a number of bolt on belt drives for sale Bruce, and reasonably priced.

People's attempts sometimes fail for a reasonably simple reason, the failure to understand that engine's 'pulse', they slow down, and then re accelerate every cylinder's cycle, so the crankshaft doesn't turn at one constant speed, besides flexing, while the propeller wants to and does continue at one speed. It is this fight that causes the bulk of the issues. Allowing them to run at their separate speeds, such as flexible drive or one way clutch between them, goes a long way to resolving many of the seen issues.

 

I once resolved an issue with a large solidly mounted, single cylinder engine driving a hydraulic pump that was constantly tearing out the fiber drive isolators, by mounting it using rubber engine mounts. They were positioned specifically so that the engine pulses would rotate the engine back and forward around the crank's centerline (like many cars), hopefully dissipating the driveshock and TVs. It worked so apparently it did.

 

They originally didn't use rubber mounts for fear the movement would tear the drives, a valid thought, but it was what was doing the damage.

 

More cylinders and more flywheel weight go somewhat to lessening TV problems as well.

 

 

[Litespeed]

If you want cheap, cheerful and reliable then do a Heath parasol or similar design and add a total two stroke. Shop around and $2,500 for a good rotax with redrive will provide plenty of thrust in which to trust. It's all about condition and managing your two stroke.

 

The Texas parasol group is great and is very cheap to build, lots flying and not a huge amount of build hours. as it is built from angle alloy it is cheap. A tube frame in alloy of aircraft grade costs considerably more. The covering is up to you but can be cheap or very expensive eg. Oratex.

 

The more you can do and make yourself the cheaper, go second hand when possible and enjoy. A used rotax or Kawasaki or Hirth two stroke will be fine and more reliable than a home cobbled motor/ box combo.

 

Resist the temptation of a untried motor and untried airframe, too much to go wrong and you only have one life.

 

 

[bexrbetter]

Resist the temptation of a untried motor and untried airframe, too much to go wrong and you only have one life.

For those who subscribe to that, which is fair enough, but they should also resist complaining about the cost because unless people try, then nothing will change.

 

 

[facthunter]

There are some that can do engine stuff and others that can't put a plug in or drain the oil without cross threading the item.. Most 2 strokes started life as skidoo engines. Outboard high performance engines are sometimes Wankel. which is pretty bombproof if you can quieten it exhaust wise.You need a large reduction redrive usually sun and planetary from an auto trans. Single cylinder and twin FOUR strokes can be a bit lumpy when mounted in a lightweight frame and probably need very elastic mounts to let them move about . Nev

 

 

[Litespeed]

Sure experiment with a new airframe design or motor, but only do one at a time. Sure you can be bold but few bold builders live to be old pilots.

 

Pilots who fly new designs with new engines are called test pilots. And deserve the title if good enough, if not they are called the deceased more often than not.

 

 

[Soleair]

Sure experiment with a new airframe design or motor, but only do one at a time. Sure you can be bold but few bold builders live to be old pilots.*

Here is an example of a new engine in a new airframe (& here is one review from Flight Internationa). Conceived from scratch as an attempt to get away from using heavy, expensive American aero engines from the 1950's.

No progress without someone willing to depart from entrenched tradition.

 

Bruce

 

*p.s. I'm 67. Does this count as old?

 

 

[facthunter]

Well It's not an easy Row to Hoe. Hewland used to make racing car gearboxes. 800 hours is a good life for a two stroke. Nev

 

 

[fly_tornado]

If you want cheap, cheerful and reliable then do a Heath parasol or similar design and add a total two stroke. Shop around and $2,500 for a good rotax with redrive will provide plenty of thrust in which to trust. It's all about condition and managing your two stroke.

the problem with that philosophy is most rotax's are getting very long in the tooth

 

 

[old man emu]

The Affordaplane has been mentioned as a cheap DIY project. The designer has produced an easy-to-read builder's manual. There are a number of planes that are built using aluminium square tube (some of Morgan's designs come to mind), so obtaining a copy of this builder's manual would be a good idea for anyone wanting to work in this medium. Here is a link to a source.

 

http://manosparnai.lt/e107_files/public/1322758845_1_FT0_builders_manual.pdf Even if you are a woodpecker, this manual has some good, clear information about aircraft hardware.

 

A full set of Affordaplane plans, in digital format, is available for $US19.95 (about $AU25.00). Welcome To Affordaplane Affordable Ultralight Aircraft

 

The unfortunate thing about most of the planes in this category is that they are only suited for blokes built like a match with the wood scrapped off.

 

 

[farri]

This is the timing belt reduction drive I chose...At the time there had been a number of Rotax B type gearbox failures so I reasoned I could inspect the components of the belt drive, at preflight! from memory, it did around 130 trouble free hours before Cyclone Joy damaged my AC and I stored it.....It`s held to the engine by 2 pieces of Aluminum angle and the adjusting arms are attached to those...It`s been sitting in a box since 1990.

 

 

Frank

 

 

 

[onetrack]

What is this "ALCAN Supral" aluminium that they speak of, in the construction of the ARV Super2? I can find nothing on it. Was it a prototype of some new form or profile of aviation aluminium, that never made it to production?

 

 

[farri]

Wikipedia.

 

Design and development[edit]

 

ARV Super2 aircraft, with the first prototype flying on 11 March 1985.[10] The factory used some novel manufacturing techniques, including British ALCAN's "Supral"[11] (a superplastic aluminium alloy), adhesives (to reduce the number of rivets and thereby save weight), and a bespoke new British engine, the Hewland AE75. These innovations gave the ARV an empty weight 40% lower than the Cessna 152,[12] making the Super2 both cheaper to buy and to operate.

 

Frank.

 

 

[onetrack]

Frank - O.K., I got information on the "Supral" now - it's a "superplastic" aluminimum.

 

But it appears to be a strange material for use in an aircraft - it's only rated for "uncritical" uses, because its properties are plasticity, not strength.

 

http://core.materials.ac.uk/repository/eaa/talat/3804.pdf

 

 

[Benawen]

I would rather use a second hand hirth or Rotax or any purpose designed aero engine as opposed to motorbike or jet ski conversions. YODO (you only die once)

 

 

[fly_tornado]

the rotax aviation line started off as a snowmobile engines, there isn't enough volume in aviation sales to develop an engine properly.

 

 

[SSCBD]

This is the timing belt reduction drive I chose...At the time there had been a number of Rotax B type gearbox failures so I reasoned I could inspect the components of the belt drive, at preflight! from memory, it did around 130 trouble free hours before Cyclone Joy damaged my AC and I stored it.....It`s held to the engine by 2 pieces of Aluminum angle and the adjusting arms are attached to those...It`s been sitting in a box since 1990.[ATTACH]53995[/ATTACH] [ATTACH]53996[/ATTACH]

Frank

Heh Frank - is that a Van Pragg built reduction?

[farri]

Heh Frank - is that a Van Pragg built reduction?

A long time ago, lousy memory but the name rings a bell! I think so! I recall someone down south making it up for me.

Frank.

 

 

[facthunter]

The early Rotax's had crankshaft failures near the drive end. There's not a lot of development in a 600 CC liquid cooled Rotax.. (talking two strokes here.) The 912 series has a pretty exotic drive but it still needs attention periodically and sounds gross when you shut the motor down. Probably 1/4 the price at least of the engine package, which most agree is not a cheap item.. Nev

 

 

[Nobody]

I wonder why the HKS 700e has not been more successful? They were about $10k a few years ago. Not sure now. While not cheap it seemed well developed...

 

 

[fly_tornado]

Fukushima killed the HKS700, once Japan started shutting down its nuclear power plants electricity got very expensive and that killed off the production

 

 

[facthunter]

It was promoted as a direct replacement for the 582 Rotax 2 stroke. I'm not quite sure if it equalled the power, but it was close. It seemed to be running too high a compression but certainly had potential.. Nev

 

 

[Soleair]

What is this "ALCAN Supral" aluminium that they speak of, in the construction of the ARV Super2? I can find nothing on it. Was it a prototype of some new form or profile of aviation aluminium, that never made it to production?

 

Frank - O.K., I got information on the "Supral" now - it's a "superplastic" aluminimum.But it appears to be a strange material for use in an aircraft - it's only rated for "uncritical" uses, because its properties are plasticity, not strength.

http://core.materials.ac.uk/repository/eaa/talat/3804.pdf

ARV wanted to use aluminium rather than composites for the Super2 airframe. But it's hard to get away from a fairly boxy appearance when you're limited to curvature in a single plane (sorry). By using Supral, compound curvature of the aluminium components allowed the styling of composites, but manufactured in ally. Supral starts as a flat sheet. It is positioned over a female meehanite mould, sealed, heated to about 450º, & blow moulded to shape.

Between the main frame, which supports the wings, u/c, seating, etc, and the firewall, where all the shaping & change of sections occur, there are only 4 components: the floor pan; 2 side panels, & the upper cockpit coaming. The floor pan included a tunnel (like you used to get as a transmission tunnel in older cars), through which ran the radiator plumbing. The side panels included 2 styling strakes halfway up. Both the floor tunnel & the strakes were there to stiffen the structure. The upper coaming embodied a constantly changing recessed channel that the canopy fitted into snugly. And yet all these details were included on the moulds, so instead of many small, fiddly bits of aluminium fabrication, these features, plus joggles where the panels joined, were all included in those 4 parts as formed. A massive saving in fabrication time, as well as the styling advantages.

 

ARV was the first, and as far as I know, still the only Approved aircraft company to use superplastic aluminium in primary structure. Because of the 'eggshell' concept of the cockpit area, this material was amply strong & stiff enough for the loads imposed. Indeed, at least one ARV pilot crashed into trees, tore off the wings, & cartwheeled to a stop. He emerged unscathed from the cockpit. It may be that Alcan's legal eagles have since insisted that the material is not to be used as primary structure, but such is the impact of the litigious society on suppressing development.

 

Bruce

 

 

[Guest Guest]

It

 

I guess it come down to what you are willing to do in order to aviate. If it came down to a choice between constant tinkering or not flying, I'm pretty sure I'll go with constant tinkering.

.......,also boils down to how much you put on yr own life, I'd never get in most of what is known as an ultralight, self preservation kicks in-;)