Thinking of buying it for a couple grand. Build by a retired engineer (who has since passed) for his grandson. The grandson wasn't interested. So the son wants it out of hospital garage. bird is completed.but not yet flown. What do you guys think?

https://cimg8.ibsrv.net/gimg/pprune....922ea03c49.jpg
What is it?

Are those meat thermometers sticking out of the cooling ribs?

An RC-helicopter?

What can go wrong?

I think that thing is called a G1 from a company long gone.
It is said, that it can not autorotate.
I would suggest to make it an RC-Helicopter and hope for a spectacular crash for TikTok. A live sized Barbie would look good. Or Playmobil.
My price for that? You have to pay me.

A MKII dangerous .

I think, I would remove the seat, servo up the controls and make it remote controled platform to do heli logging in my back yard.
I am sure it can lift 100 pounds of something

https://www.vortechonline.com/g1/grfx/g1.jpg
then you got 3 engines, so its a fail safe plan :}

Could it be a far distant relation to this?
https://cimg9.ibsrv.net/gimg/pprune....7b0bde3780.jpg

Max altitude 10,000ft according to the brochure. Seems like a bargain. Go for it.

https://www.vortechonline.com/g1/

Wow, a three engine aircraft ! Triple Briggs and Stratton ?

There's minimalist, then there's Minimalist.

https://cimg9.ibsrv.net/gimg/pprune....fb543a7ceb.jpg


If you're intending to explore M. Sablier's altitude envelope, I'd suggest tweeds and stout walking shoes.

Does anyone know what this is? - Yes, your in luck - bloody dangerous.

What do you guy’s thing? - I’m loving the overhead fuel tank, reminds me of the Ford Pinto, or is it the Aventador.

PAN PAN
 

PAN PAN - one POB meat ready need to land as I like my steak medium rare.😳

The Roger Bacon phrase "sudden not entirely unexpected twang" rises irresistibly to the surface of my mind...

My suggestion would be to offer it to the Helicopter Museum at Brandywine Airport in Pennsylvania...

Looks like a recipe for a world of pain!

​​​​​​​Smart lad.

Casper posted an interesting photo where folks questioned three engines but did not query the notion of the single rubber belt driving the rotor system.

I suppose some here are not risk averse but are brain washed by the industry focus upon engine failure while ignoring far more critical safety issues.

There are other helicopters with single belt drives. And that one is presumably for the tailrotor. I think that the flimsy plastic pully is way more frightening.

But one must admire all the torque stripes ... or blotches.

I don't think the three engines are a safety feature. They are all needed because that thing can not fly on two engines. Therefore they are an unsafe feature.

Like the Enstrom I learned to fly in! It autorotated beautifully though.

Thread drift, but can anybody work out how the George Sablier personal rotorcraft was supposed to work? There are some cryptic references to how the torque from the rotor was counteracted but all I can see is a small fin/rudder behind the operator which seems to be oriented at the wrong angle to counter any torque in any case. This item also casts doubt:
https://elpoderdelasgalaxias.wordpre...ter-rotorhead/

Only photos I found are of it demonstrated on the ground, not flying. So did it ever fly? Some photos like the above seem to show a pulley arrangement below the rotor but lacking any drive belts. So was the rotor only spinning in the photos due to autorotation in wind? There is no hint it had any tip jets to drive the rotor.

Back to the OP: what a complicated and precarious looking drivetrain!

There's a chap in the UK putting a co-axial helicopter together, from scratch, of his own design ... https://www.youtube.com/@Ben-Dixey/videos

Looks like a home-made gyrocopter or similar ?

I would not go near that in a million years !, and definitely would not fly it !!

e.g. tail rotor driven by a long rubber belt.........

You'll kill yourself.

That cardboard box in the corner indicates a worrying potential component source ! ;)

Joking apart; things such as the plastic fuel pipe and plastic fuel filters with joints held together with ty-wraps, (aka zip ties); pieces of aluminium angle, but what type of aluminium - what alloy, i.e what strength and resilience does it have in an aircraft environment - or is it just from B&Q, (no disrespect to B&Q). Ditto, what is the specification of all the bolts ?

You simply don't know, so honestly, I would run a mile from that and NEVER fly yourself in it. You could possibly use it for parts to make a large radio controlled model of some sort, but only pay a few hundred for it at most.

I remember reading an accident report where a similar craft had used plastic fuel pipe which had become compromised by shrinking in the lower temperatures aloft, causing fuel starvation and a serious problem.

Just don't go there.

Personally, I'd put the thermometers on the bottom engine as, like multi-row radials, getting cooling air to the back of the engine (bottom in this case) can be difficult, especially as all the cylinder heads are aligned. It looks like the engines are connected to the rotor shaft via chains; if one engine fails, does the shaft lock up or are there free wheeling devices? There was a guy, Manolis IIRC, who used to post on F1 Technical about his 2 stroke flying pogo stick; this actually looks safer.

You know, its a jolly good job the early aviation pioneers didn't worry about the kind of small details you lot are worried about, if they had aviation would never have progressed beyond Montgolfier 😊!

Right, so you would be happy to strap into this and take off in it ?

Winemaker: those look like centrifugal clutches on the engines driving the chains. So if an engine failed it would probably disconnect itself from the output shaft.

But even so...............

If I was an early aviation pioneer - probably.

I hope to hell, 1) you're well insured, 2) you have top cover medical insurance and 3) you have bigger conjones than me ! Good luck, I mean it

And did they?

A very thrilling 3.5 minutes followed by a tragic ending.

Why not?

No freewheel between drive and rotor? I can't see one.

It's also fixed pitch, there is no cyclic or collective control.

Is it? I see a collectiv and some flimsy cables running up the mast. What I don't see is a cyclic. I think that is more relevant. Probably someone needed the broom stick.
I don't know, why that thing does not autorotate.

There are some photos of a different project here: Ultralight G 1 Helicopter : ULTRALIGHT G 1 HELICOPTER A complete G1
It looks like a direct drive from engine(s) to rotor, without any option to adjust cyclic other than shifting your weight around. You would need some sort of clutch/freewheel option to allow autorotation. Mind you, there will not be a lot of energy in that rotor disc anyway and you would also need a collective control to enable you to arrest the downward motion. I'm still not sure how any kind of control is applied to those blades.