You airplane geeks will love this. My son bought his three-year-old an Air
Hogs "Twin Fury" plane at Toys-R-Us on sale for $12.95 Saturday. This is a
twin-engined pneumatically powered toy airplane that is very, very clever.
Here's a link to a picture of it.

http://www.amazon.com/exec/obidos/tg...#more-pictures

What is really clever is the design of the motors. These are tiny little
pneumatic motors with only three moving parts each, designed for them by a
consulting firm: http://www.rehkemper.com/airmotor.html The original Air
Hogs pneumatic motor apparently cost 50 cents to make. These new motors are
more efficient and cost 8 cents (!) to make.

When pumped up to the recommended pressure (50 strokes on the supplied pump)
the motors run for roughly 10-15 seconds, initially giving enough thrust to
almost lift the plane on its props. Amazing amount of thrust. Gareth set
his off the first time and claims that it climbed to nearly 300 feet and
flew around for a couple of minutes. The second time it ended up in a high
tree and could not be recovered. No problem; at @ $12.95 he bought another
one. Now that he knows how far it can fly, he's going to be more careful
about where he launches it.

Yesterday I bought one too, only for me.

--
Bob (Chief Pilot, White Knuckle Airways)

"Bob Chilcoat" wrote in message
...
You airplane geeks will love this. My son bought his three-year-old an
Air Hogs "Twin Fury" plane at Toys-R-Us on sale for $12.95 Saturday.
This is a twin-engined pneumatically powered toy airplane that is very,
very clever. Here's a link to a picture of it.

http://www.amazon.com/exec/obidos/tg...#more-pictures

What is really clever is the design of the motors. These are tiny little
pneumatic motors with only three moving parts each, designed for them by a
consulting firm: http://www.rehkemper.com/airmotor.html The original Air
Hogs pneumatic motor apparently cost 50 cents to make. These new motors
are more efficient and cost 8 cents (!) to make.

When pumped up to the recommended pressure (50 strokes on the supplied
pump) the motors run for roughly 10-15 seconds, initially giving enough
thrust to almost lift the plane on its props. Amazing amount of thrust.
Gareth set his off the first time and claims that it climbed to nearly 300
feet and flew around for a couple of minutes. The second time it ended up
in a high tree and could not be recovered. No problem; at @ $12.95 he
bought another one. Now that he knows how far it can fly, he's going to
be more careful about where he launches it.

Yesterday I bought one too, only for me.

--
Bob (Chief Pilot, White Knuckle Airways)

Bob,
If you really want to get some air time out of those .. fill it's tank with
butane from one of the cans they use for butane lighters. It goes in as a
liquid and turns to gas at a rate that keeps em running a really long time
I bought my son a car like that years ago and we "discovered" that a
little butane would make it run for blocks on a single fill.

Glenn

Anyway, yes the motor is clever... No it is not totally new... Any gear
head able to walk and chew gum recognizes it as a bump valve steam
engine... The original thinking is using a fixed shelf as the piston,
with eccentric faces that allow the extended piston head to swing in an
arc... This will work at low speeds and low pressures with a neoprene
0-ring as the piston seal...

denny

Hey Bob,

Pretty neat eh!?!?

Looking at the rehkemper site, I can't figure out how it "exhausts"
though. Maybe through the connecting "rod" and the crank?

I did see some electric engine completely RTF R/C planes at Harbor
Freight the other day for just $27.95.

Take care.

Brian Lawson,
Bothwell, Ontario.
XXXXXXXXXXXXXXXXXXXXXXX



On Mon, 1 May 2006 14:15:40 -0400, "Bob Chilcoat"
wrote:

You airplane geeks will love this. My son bought his three-year-old an Air
Hogs "Twin Fury" plane at Toys-R-Us on sale for $12.95 Saturday. This is a
twin-engined pneumatically powered toy airplane that is very, very clever.
Here's a link to a picture of it.

http://www.amazon.com/exec/obidos/tg...#more-pictures

What is really clever is the design of the motors. These are tiny little
pneumatic motors with only three moving parts each, designed for them by a
consulting firm: http://www.rehkemper.com/airmotor.html The original Air
Hogs pneumatic motor apparently cost 50 cents to make. These new motors are
more efficient and cost 8 cents (!) to make.

When pumped up to the recommended pressure (50 strokes on the supplied pump)
the motors run for roughly 10-15 seconds, initially giving enough thrust to
almost lift the plane on its props. Amazing amount of thrust. Gareth set
his off the first time and claims that it climbed to nearly 300 feet and
flew around for a couple of minutes. The second time it ended up in a high
tree and could not be recovered. No problem; at @ $12.95 he bought another
one. Now that he knows how far it can fly, he's going to be more careful
about where he launches it.

Yesterday I bought one too, only for me.

On Mon, 1 May 2006 14:15:40 -0400, "Bob Chilcoat"
wrote:


What is really clever is the design of the motors. These are tiny little
pneumatic motors with only three moving parts each, designed for them by a
consulting firm: http://www.rehkemper.com/airmotor.html

I take my hat of to those guys. that is a neat design.
worthy of a design award.
Stealth Pilot

If you really want to get some air time out of those .. fill it's tank with butane from one of the cans they use for butane lighters.

To avoid another TWA 800 tragedy, you'd need a fuel cell inerting
device. Then again, without any lives at risk it'd make an impressive
aerial flamethrower...

In rec.crafts.metalworking Glenn wrote:
If you really want to get some air time out of those .. fill it's tank with
butane from one of the cans they use for butane lighters. It goes in as a
liquid and turns to gas at a rate that keeps em running a really long time
I bought my son a car like that years ago and we "discovered" that a
little butane would make it run for blocks on a single fill.
--Hey neat idea; I'll have to try this with my High Hopping
Hoomdorm! :-)

--
"Steamboat Ed" Haas : I'll have the roast duck
Hacking the Trailing Edge! : with the mango salsa...
www.nmpproducts.com
---Decks a-wash in a sea of words---

"Kingfish" wrote

To avoid another TWA 800 tragedy, you'd need a fuel cell inerting
device. Then again, without any lives at risk it'd make an impressive
aerial flamethrower...

Why not put a collector on the exhaust, and a small combustion chamber with
igniter. Jet power, anyone? g
--
Jim in NC

"Morgans" wrote in message
news

"Kingfish" wrote

To avoid another TWA 800 tragedy, you'd need a fuel cell inerting
device. Then again, without any lives at risk it'd make an impressive
aerial flamethrower...

Why not put a collector on the exhaust, and a small combustion chamber
with igniter. Jet power, anyone? g
--
Jim in NC

Hmmm, I wonder if there is enough pressure there for a glow-plug to do the
ignition??

Glenn wrote:
... fill it's tank with
butane from one of the cans they use for butane lighters. ...

neat idea! But ... I would recommend a pressure comparison. The OP
said it takes 50 strokes of the pump. There's no telling what that
means in psi. It could be a lot more than the vapor pressure of butane,
or not. And consumer "butane" is usually a mix of butane and propane
(IIRC), so the vapor pressure can vary. I would measure the pump
pressure and that of the butane first. Not that I would worry about
explosions, but destroying the plane.

Bob

In article ,
"Bob Chilcoat" wrote:

You airplane geeks will love this. My son bought his three-year-old an Air
Hogs "Twin Fury" plane at Toys-R-Us on sale for $12.95 Saturday. This is a
twin-engined pneumatically powered toy airplane that is very, very clever.
Here's a link to a picture of it.

http://www.amazon.com/exec/obidos/tg...3414-1923819?v
=glance&s=toys&n=1162224&vi=pictures&img=14#more-pictures

What is really clever is the design of the motors. These are tiny little
pneumatic motors with only three moving parts each, designed for them by a
consulting firm: http://www.rehkemper.com/airmotor.html The original Air
Hogs pneumatic motor apparently cost 50 cents to make. These new motors are
more efficient and cost 8 cents (!) to make.

When pumped up to the recommended pressure (50 strokes on the supplied pump)
the motors run for roughly 10-15 seconds, initially giving enough thrust to
almost lift the plane on its props. Amazing amount of thrust. Gareth set
his off the first time and claims that it climbed to nearly 300 feet and
flew around for a couple of minutes. The second time it ended up in a high
tree and could not be recovered. No problem; at @ $12.95 he bought another
one. Now that he knows how far it can fly, he's going to be more careful
about where he launches it.

Yesterday I bought one too, only for me.

So you're the marketing director for Rehkemper, Bob? Could your firm
design a spam-powered motor?

On Tue, 02 May 2006 08:48:23 -0400, Brian Lawson
wrote:

Hey Bob,

Pretty neat eh!?!?

Looking at the rehkemper site, I can't figure out how it "exhausts"
though. Maybe through the connecting "rod" and the crank?

I did see some electric engine completely RTF R/C planes at Harbor
Freight the other day for just $27.95.

Take care.

Brian Lawson,
Bothwell, Ontario.
XXXXXXXXXXXXXXXXXXXXXXX

The patent talks about some grooves for exhaust. I couldn't make any
sense of that, but there is also a drawing in the patent that shows
the motor in various positions. The piston clearly rocks as the
motor runs. It looks to me like the piston seals when it's tilted
one way, also opening opening the inlet valve for the power stroke,
but air can leak around part of the piston during the recovery stroke
when the inlet valve is closed and the piston is tilted the other
way. There's a hole in the "crankcase" for exhaust to escape thru
when it has bypassed the piston.

On Thu, 04 May 2006 05:38:30 -0700, Smitty Two
wrote:

In article ,
"Bob Chilcoat" wrote:

You airplane geeks will love this. My son bought his three-year-old an Air
Hogs "Twin Fury" plane at Toys-R-Us on sale for $12.95 Saturday.
snip

Yesterday I bought one too, only for me.

So you're the marketing director for Rehkemper, Bob? Could your firm
design a spam-powered motor?

And you cross-post that idiotic response? plonk.

On Thu, 04 May 2006 11:34:40 -0500, Don Foreman
wrote:

SNIP

The patent talks about some grooves for exhaust. I couldn't make any
sense of that, but there is also a drawing in the patent that shows
the motor in various positions. The piston clearly rocks as the
motor runs. It looks to me like the piston seals when it's tilted
one way, also opening opening the inlet valve for the power stroke,
but air can leak around part of the piston during the recovery stroke
when the inlet valve is closed and the piston is tilted the other
way. There's a hole in the "crankcase" for exhaust to escape thru
when it has bypassed the piston.


OK. Thanks Don,

I didn't pursue the patent very far, just looked at the "video clip".

Take care.

Brian Lawson