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Ivoprop claims that the Magnum 3 blade
weighs 26.7 pounds.
http://www.ivoprop.com/inflightmagnumodel.htm
Bill B
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Rob Bollinger
Sent: Tuesday, February 26, 2013
12:02 PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: 13B
weight and CG location
My Ivo electric magninum 3 blade weight is 27 pounds. It
can't be 7 pounds.
On Tue, Feb 26, 2013 at 8:18 AM, Kenneth Johnson <kjohnsondds@yahoo.com>
wrote:
Hi Gordon,
I had to go out and reweigh my Ivoprop. I do not know if you are familiar
with this prop? The blades are made of carbon fiber and do not weigh
much. A metal blade (shaft) runs down the center of each blade. An
electric motor applies force to the metal blades inside each carbon fiber
blade, which twists the blades, changing the pitch of each blade. The
term used is an in-flight-electrical adjustable pitch prop. The motor and
contact discs on the center shaft make up most of the weight. All
together the 3 carbon blades and motor prop system weigh about 7 lbs.
Their placement is about a foot out further anterior than if I used a Lycoming
engine. Ken Johnson
Thanks for your info.
You are correct that I am trying to determine the position of the engine for
proper aircraft CG location. At the moment, I’m trying to design the
engine mount truss for the design loads. If I know the weight and CG
location of the engine/prop assembly, I can model the loading in truss analysis
software and play “what if” games with different truss configurations.
Your 300 Lb. figure for the engine/redrive assembly and your heat exchanger
weights is a start. What does your IVO prop weigh?
Thanks again for the
help.
Gordon C. Alling,
Jr., PE
acumen Engineering/Analysis, Inc.
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
On Behalf Of Kenneth Johnson
Sent: Sunday, February 24, 2013
7:02 PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: 13B weight
and CG location
Hi Gordon,
I am not certain what you are asking. It would seem you are asking if you
can use a DIY engine mount, and therefore, you are asking how far from the
firewall should you place your engine? This is what I found with my engine.
I am using a 13B NA engine with a PowerSport redrive. The weight of my
engine and redrive is 295 lbs. My radiator weighs 15 lbs and the oil
cooler weights 7 lbs. I found that when adding the weight of the radiator
and oil cooler fluids, that my engine system would come very close to the
weight of a Lycoming 360. It was estimated that the average weight of the
prop would be 27 lbs. My Ivoprop weighs less than that, but the prop is
positioned much farther anterior than with a Lycoming because of the
redrive. So, the arm is out there. Tracy's point on the cg of the engine being
positioned just inside the first end plate would be pretty accurate.
I am getting closer to finishing a Zenith 801, so I am yet unable to offer
actual flight experience. Zenith did provide numbers for the installation
of a Lycoming 360 and I compared my numbers to theirs. I had anticipated
that I would be placing my engine a great distance from the firewall because
everyone says the 13B is so light. However, after adding the weight of
all the "extras," plus the fact that the arm of my prop is out a much
greater distance than with a Lycoming, I actually had to move the engine closer
to the firewall than if I used a Lycoming. I concluded that I needed to
design and build my own engine mount.
I hope this is helpful.
Ken johnson
I’m considering a DIY engine mount for my turbo 13B
engine. Does anyone out there with an operating 13B (turbo or NA) have
good numbers for the installed weight and CG location for his/her
engine/redrive/prop combination? I want some ballpark numbers to get
started.
Gordon C. Alling, Jr., PE
acumen Engineering/Analysis,
Inc.
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