A> Don Dunbar wrote:

Hello ACRE,

Hi Paul,
I have come across a new product that I think would make a good prop
blade as it has other properties that Carbon fibre does not.
The product is fibre glass reinforced polypropylene. It does not have
the tensile of carbon fibre but does not chip and fracture like other
resins. The most popular use for this product is for under body
protection for Rally cars and high impact and abrasion components.
The tensile of this material is 350 mpa with good flexibility.
It comes as glass impregnated and is vacuumed into moulds and place in
the oven for curing. Steel or alloy moulds work best as they transfer
the heat better.
What are your comments

--
Best regards,
 Don                            mailto:ddunbar@echidna.id.au

A> Worth a test on the ground. The U.S. FAA required it spun up to twice
A> redline as a test as I recall. I don't know how one could
A> do that with out a zillion HP. Perhaps if you just used a static
A> pull on the end of the blade with a calculated load of
A> twice the expected blade mass centrifugal force.

A> Another question is heat generated in the hub either by conductance
A> from the engine heat or slip friction because the prop bolts are not
A> torque down properly. What is the max temp of polypropylene?

A> A third issue is blade torsional stiffness. Glass has a much lower modulas of
A> elasticity than carbon fiber so it could untwist at high thrust levels.
A> Tracy Saylor thinks he ran into that problem with the MT wood and glass
A> composite propeller. It was untwisting compared to his aluminum
A> constant speed prop he usually uses to go 240 MPH in his RV6. Slowed
A> the top speed down about ten MPH.

A> BTW how is your 13B powered Mustang II coming? You should be close to flying.

A> Paul Lamar

A> The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
A> ACRE NL web site. http://home.earthlink.net/~rotaryeng/
A> Copyright 1998-2003 All world wide rights reserved.

Operation tempreture is -40 to +100 c and UV stabilised
Molding temp is 180 to 230 c
The stiffness tensile Gpa is 15 where Carbon fibre Epoxy is 110.
They are making hot water pressure vessel from this stuff.
I have a friend with a Prince prop on his Longeasy which is glass
epoxy that has a stiffness tensile Gpa of 300. He has tried some 6
propellers and believes this is the best he has had due to the
flexiablity.

Paul the Mustang had come to a halt for some 4 months as I have been
building a new hanger at Serpentine which is 18x13 metre.
I purchased a Dynon EFIS 10 for the Mustang but installed it in the
Jabiru to test and liked so much that I will buy another for the
Mustang. The next task on the Mustang is the wiring and panel layout,
al the equipment has been purchased and I will start work on it this
week as all the other project are complete.

I have been traveling a bit and this has taken up to much time.
Paul I have purchased a new computer that you may be interested in !
it is what they call a desktop replacement that has a 17" screen.
Have a look at Mitac-mtc.com They also have a 15' wide screen note
book with a titanium case at 2.4 kg.
--
Best regards,
 Don                            mailto:ddunbar@echidna.id.au

The AirCraft Rotary Engine NewsLetter.  Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/            
Copyright 1998-2003 All world wide rights reserved.