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#97589 From: "steve" <steveslade@...>
Date: Fri Dec 11, 2009 7:47 pm
Subject: RE: Re: engine weights and flappy props
steveslade2001
Offline Offline
Send Email Send Email
 
The GSC I use on my Rans 912 is an excellent combination - very good
efficiency.  Just bought my first one in 7 years - not bad for a wooden
prop.

Steve

   -----Original Message-----
   From: microlights@yahoogroups.com [mailto:microlights@yahoogroups.com]On
Behalf Of Kev A
   Sent: 11 December 2009 13:15
   To: microlights@yahoogroups.com
   Subject: [microlights] Re: engine weights and flappy props



   Can only speak as I find; The Ivoprop exact same size, blades and pitch on
my 447 Chaser was heavier, took much longer to spin up and was less
efficient in terms of throttle opening versus hands-off cruise compared to
the glassfibre Arplast.

   Jeremy Harris disliked Ivos too; They are cheap and easy to adjust, but on
efficiency and general performance the Warp and Arplast beat them hollow.
Possibly those flexible blades are less accurate at holding a particular
pitch? Downside of the Arplast is fragility, if touring France I'd go for
the Warp in case the odd runway stone thrown up stranded me somewhere. This
is why P&M use them, less bother all round.

   If reverting to SSDR, which is looking ever more likely now, then flying
would be more or less local area, so an Arplast would be fine. Pricey
though, but what a lovely smooth and quiet prop.

   Does any propeller combine Arplast efficiency with Warp Drive toughness?
The old two blade Newtons were pretty good as long as you checked the prop
bolts regularly. Look old-fashioned but work very well. They use them on
modern UAVs so wood isn't dead yet.

   Kev

   djs_chaser" <david.stickney@...> wrote:
   >
   > Ivo should be good in this respect. It's got a VERY flexible blade. I
remember seeing a demo exhibit on the Warp Drive (IIRC) stand at a Sun and
Fun years ago. It was a vertical post with one each of an Ivo and a Warp
Drive blade sticking out from the top like a letter 'T'. They'd hung weights
from the tips of each blade. The Ivo was bent to nearly 45 degrees, whilst
the WD was still pretty much horizontal.
   >
   > They were making the point that their blades were so much stiffer than
the Ivo. I remember thinking that this was pretty pointless (pun intended),
as centrifugal force sorts it all out. But I'd never considered that the
flexibility is, in fact, a GOOD thing, as Laurie points out below...
   >
   > Dave
   >
   > --- In microlights@yahoogroups.com, "lauriehurman" <lauriehurman@>
wrote:
   > >
   > > Thanks Kev
   > >
   > > The only significant bending force on the prop blade occurs at
take-off and landing.
   > > The moment when the trike wheel touches the ground the trike rotates
quickly and induces very large out of plane bending loads in the prop due to
gyroscopic procession. I think most 3-axis might be a bit easier on the prop
from this point of view.
   > >
   > > The rest of the time there is not much bending on the blade and it
would be relatively easy to make it zero if you wanted to - either dishing
the blade or putting in a flapping joint.
   > >
   > > Laurie (2)
   > >
   > > --- In microlights@yahoogroups.com, "Kev A" <kevin@> wrote:
   > > >
   > > > lauriehurman" <lauriehurman@> wrote:
   > > > Back at Uni we used to learn to measure rotational inertia with the
"trifilar" experiment. Does anyone have a reference to this to save me
trying to work it out from scratch.
   > > >
   > > > Rotax give it here:-
   > > >
   > > > http://www.rotax-owner.com/si_tb_info/serviceinfo/11ul91.pdf
   > > >
   > > > More I think about this, the more attractive a lighter propeller
becomes; I was surprised P&M fitted an Ivo to their SSDR trike; hardly the
lightest make around with those chrome-moly steel rods down each blade.
   > > >
   > > > Cheers
   > > >
   > > > Kev
   > > >
   > >
   >




   No virus found in this incoming message.
   Checked by AVG - www.avg.com
   Version: 9.0.709 / Virus Database: 270.14.102/2556 - Release Date:
12/10/09 07:36:00



[Non-text portions of this message have been removed]

#97588 From: "Kev A" <kevin@...>
Date: Fri Dec 11, 2009 1:14 pm
Subject: Re: engine weights and flappy props
factoryfit
Offline Offline
Send Email Send Email
 
Can only speak as I find; The Ivoprop exact same size, blades and pitch on my
447 Chaser was heavier, took much longer to spin up and was less efficient in
terms of throttle opening versus hands-off cruise compared to the glassfibre
Arplast.

Jeremy Harris disliked Ivos too; They are cheap and easy to adjust, but on
efficiency and general performance the Warp and Arplast beat  them hollow.
Possibly those flexible blades are less accurate at holding a particular pitch?
Downside of the Arplast is fragility, if touring France I'd go for the Warp in
case the odd runway stone thrown up stranded me somewhere. This is why P&M use
them, less bother all round.

If reverting to SSDR, which is looking ever more likely now, then flying would
be more or less local area, so an Arplast would be fine. Pricey though, but what
a lovely smooth and quiet prop.

Does any propeller combine Arplast efficiency with Warp Drive toughness? The old
two blade Newtons were pretty good as long as you checked the prop bolts
regularly. Look old-fashioned but work very well. They use them on modern UAVs
so wood isn't dead yet.

Kev


djs_chaser" <david.stickney@...> wrote:
>
> Ivo should be good in this respect.  It's got a VERY flexible blade.  I
remember seeing a demo exhibit on the Warp Drive (IIRC) stand at a Sun and Fun
years ago.  It was a vertical post with one each of an Ivo and a Warp Drive
blade sticking out from the top like  a letter 'T'.  They'd hung weights from
the tips of each blade.  The Ivo was bent to nearly 45 degrees, whilst the WD
was still pretty much horizontal.
>
> They were making the point that their blades were so much stiffer than the
Ivo.  I remember thinking that this was pretty pointless (pun intended), as
centrifugal force sorts it all out.  But I'd never considered that the
flexibility is, in fact, a GOOD thing, as Laurie points out below...
>
> Dave
>
> --- In microlights@yahoogroups.com, "lauriehurman" <lauriehurman@> wrote:
> >
> > Thanks Kev
> >
> > The only significant bending force on the prop blade occurs at take-off and
landing.
> > The moment when the trike wheel touches the ground the trike rotates quickly
and induces very large out of plane bending loads in the prop due to gyroscopic
procession. I think most 3-axis might be a bit easier on the prop from this
point of view.
> >
> > The rest of the time there is not much bending on the blade and it would be
relatively easy to make it zero if you wanted to - either dishing the blade or
putting in a flapping joint.
> >
> > Laurie (2)
> >
> > --- In microlights@yahoogroups.com, "Kev A" <kevin@> wrote:
> > >
> > > lauriehurman" <lauriehurman@> wrote:
> > > Back at Uni we used to learn to measure rotational inertia with the
"trifilar" experiment. Does anyone have a reference to this to save me trying to
work it out from scratch.
> > >
> > > Rotax give it here:-
> > >
> > > http://www.rotax-owner.com/si_tb_info/serviceinfo/11ul91.pdf
> > >
> > > More I think about this, the more attractive a lighter propeller becomes;
I was surprised P&M fitted an Ivo to their SSDR trike; hardly the lightest make
around with those chrome-moly steel rods down each blade.
> > >
> > > Cheers
> > >
> > > Kev
> > >
> >
>

#97587 From: "djs_chaser" <david.stickney@...>
Date: Fri Dec 11, 2009 12:36 pm
Subject: Re: engine weights
djs_chaser
Offline Offline
Send Email Send Email
 
Ivo should be good in this respect.  It's got a VERY flexible blade.  I remember
seeing a demo exhibit on the Warp Drive (IIRC) stand at a Sun and Fun years ago.
It was a vertical post with one each of an Ivo and a Warp Drive blade sticking
out from the top like  a letter 'T'.  They'd hung weights from the tips of each
blade.  The Ivo was bent to nearly 45 degrees, whilst the WD was still pretty
much horizontal.

They were making the point that their blades were so much stiffer than the Ivo. 
I remember thinking that this was pretty pointless (pun intended), as
centrifugal force sorts it all out.  But I'd never considered that the
flexibility is, in fact, a GOOD thing, as Laurie points out below...

Dave

--- In microlights@yahoogroups.com, "lauriehurman" <lauriehurman@...> wrote:
>
> Thanks Kev
>
> The only significant bending force on the prop blade occurs at take-off and
landing.
> The moment when the trike wheel touches the ground the trike rotates quickly
and induces very large out of plane bending loads in the prop due to gyroscopic
procession. I think most 3-axis might be a bit easier on the prop from this
point of view.
>
> The rest of the time there is not much bending on the blade and it would be
relatively easy to make it zero if you wanted to - either dishing the blade or
putting in a flapping joint.
>
> Laurie (2)
>
> --- In microlights@yahoogroups.com, "Kev A" <kevin@> wrote:
> >
> > lauriehurman" <lauriehurman@> wrote:
> > Back at Uni we used to learn to measure rotational inertia with the
"trifilar" experiment. Does anyone have a reference to this to save me trying to
work it out from scratch.
> >
> > Rotax give it here:-
> >
> > http://www.rotax-owner.com/si_tb_info/serviceinfo/11ul91.pdf
> >
> > More I think about this, the more attractive a lighter propeller becomes; I
was surprised P&M fitted an Ivo to their SSDR trike; hardly the lightest make
around with those chrome-moly steel rods down each blade.
> >
> > Cheers
> >
> > Kev
> >
>

#97586 From: John Moore <cyberstitchuk@...>
Date: Fri Dec 11, 2009 11:26 am
Subject: Re: Re: Spamfield stickers
big_john_baxby
Offline Offline
Send Email Send Email
 
Tarts plane...

You from Essex?

BJ

On 11 Dec 2009, at 09:23, Mike wrote:

> No thanks John if i put 500 stickers on my CTSW it would be
> overweight ;>) ...
>
> Mike
>
> >
> > You want to buy 500 cheap Spammers stickers, Mike? Would make a good
> > repair for your tatty wing?
> >
> > BJ
> >
> >
> >
>
>
>



[Non-text portions of this message have been removed]

#97585 From: "Laurie" <lbassett@...>
Date: Fri Dec 11, 2009 11:09 am
Subject: Re: FAO Laurie Basset
l_m_bassett
Offline Offline
Send Email Send Email
 
Hi Roger, and I to yours.

best,

Laurie

--- In microlights@yahoogroups.com, "roger h" <fatcharlie@...> wrote:
>
> Hi Laurie,
>
> not trying to bring our discussion back online, but since my last email to you
went into your spam bin, I thought I'd let you know I have replied to your
reply.
>
> Cheers,
>
> Roger.
>

#97584 From: "Mick Broom" <broom.engineering@...>
Date: Fri Dec 11, 2009 9:29 am
Subject: RE: Re: engine weights
michael944631
Offline Offline
Send Email Send Email
 
Morning Laurie,
Just a gentle observation on the below.
I believe the case of the prop effect is different between trike and fixed
wing but its too early to think this to the end.
Your statement regarding prop bending or displacement should be expanded  to
cover both inertia load and air flow load. As the air flow load is
relatively fixed we do not notice it as much but it does bend the prop
blades a large amount, not only from changes in power input but from the
fact that most of our props are pushers and they load and unload as they
pass through the different air flow speeds around the aircraft.
The gyro loading has two goes at us in a fixed wing , one when we change
direction quickly ( some manage it when they fly some when they land ) with
any speed to the prop then the loads effect the plane mounts, frame and so
on.
Personally the most frightening effect for me is when soaring with engine
off or at tick-over in a big thermal, You can feel and hear the engine
swinging around on the bobbins trying to depart the plane due to its total
mass as against passing through turbs with power when you just lift off the
seat now and then as the prop gyro effect helps stabilises the back end.
Mick

   _____

From: microlights@yahoogroups.com [mailto:microlights@yahoogroups.com] On
Behalf Of lauriehurman
Sent: 11 December 2009 08:25
To: microlights@yahoogroups.com
Subject: [microlights] Re: engine weights




Thanks Kev

The only significant bending force on the prop blade occurs at take-off and
landing.
The moment when the trike wheel touches the ground the trike rotates quickly
and induces very large out of plane bending loads in the prop due to
gyroscopic procession. I think most 3-axis might be a bit easier on the prop
from this point of view.

The rest of the time there is not much bending on the blade and it would be
relatively easy to make it zero if you wanted to - either dishing the blade
or putting in a flapping joint.

Laurie (2)

--- In microlights@ <mailto:microlights%40yahoogroups.com> yahoogroups.com,
"Kev A" <kevin@...> wrote:
>
> lauriehurman" <lauriehurman@> wrote:
> Back at Uni we used to learn to measure rotational inertia with the
"trifilar" experiment. Does anyone have a reference to this to save me
trying to work it out from scratch.
>
> Rotax give it here:-
>
> http://www.rotax-
<http://www.rotax-owner.com/si_tb_info/serviceinfo/11ul91.pdf>
owner.com/si_tb_info/serviceinfo/11ul91.pdf
>
> More I think about this, the more attractive a lighter propeller becomes;
I was surprised P&M fitted an Ivo to their SSDR trike; hardly the lightest
make around with those chrome-moly steel rods down each blade.
>
> Cheers
>
> Kev
>






[Non-text portions of this message have been removed]

#97583 From: "Mike" <MIKEMICROMIKE@...>
Date: Fri Dec 11, 2009 9:23 am
Subject: Re: Spamfield stickers
micromikeuk
Offline Offline
Send Email Send Email
 
No thanks John if i put 500 stickers on my CTSW it would be overweight ;>) ...


Mike


>
> You want to buy 500 cheap Spammers stickers, Mike?  Would make a good
> repair for your tatty wing?
>
> BJ
>
>
>

#97582 From: "roger h" <fatcharlie@...>
Date: Fri Dec 11, 2009 8:55 am
Subject: FAO Laurie Basset
fatcharlieuk
Offline Offline
Send Email Send Email
 
Hi Laurie,

not trying to bring our discussion back online, but since my last email to you
went into your spam bin, I thought I'd let you know I have replied to your
reply.

Cheers,

Roger.

#97581 From: "lauriehurman" <lauriehurman@...>
Date: Fri Dec 11, 2009 8:25 am
Subject: Re: engine weights
lauriehurman
Offline Offline
Send Email Send Email
 
Thanks Kev

The only significant bending force on the prop blade occurs at take-off and
landing.
The moment when the trike wheel touches the ground the trike rotates quickly and
induces very large out of plane bending loads in the prop due to gyroscopic
procession. I think most 3-axis might be a bit easier on the prop from this
point of view.

The rest of the time there is not much bending on the blade and it would be
relatively easy to make it zero if you wanted to - either dishing the blade or
putting in a flapping joint.

Laurie (2)

--- In microlights@yahoogroups.com, "Kev A" <kevin@...> wrote:
>
> lauriehurman" <lauriehurman@> wrote:
> Back at Uni we used to learn to measure rotational inertia with the "trifilar"
experiment. Does anyone have a reference to this to save me trying to work it
out from scratch.
>
> Rotax give it here:-
>
> http://www.rotax-owner.com/si_tb_info/serviceinfo/11ul91.pdf
>
> More I think about this, the more attractive a lighter propeller becomes; I
was surprised P&M fitted an Ivo to their SSDR trike; hardly the lightest make
around with those chrome-moly steel rods down each blade.
>
> Cheers
>
> Kev
>

#97580 From: "Paul Millen" <flying@...>
Date: Thu Dec 10, 2009 7:51 pm
Subject: RE: Re: A change from aggro, a ray of Christmas Sunshine....
paul_millen
Offline Offline
Send Email Send Email
 
I have a feeling of déjà vu...

Last time this happened there was a lot of foot and mouth, spoilt fly-ins
and spamming going on, look what that lead to!

I'd prefer to fly (a bit further than the I.O.W.) so Marilyn's idea has
merit but would like longer day's and warmer weather. Is it possible to get
more central than Husband Bosworth? I don't think so!

Let the planning commence!

Paul


-----Original Message-----
From: microlights@yahoogroups.com [mailto:microlights@yahoogroups.com] On
Behalf Of Marilyn
Sent: 10 December 2009 18:24
To: microlights@yahoogroups.com
Subject: [microlights] Re: A change from aggro, a ray of Christmas
Sunshine....

That note was written for stuffing in Christmas cards to the uninitiated.
Many thanks so many liked it - you are all great.

As far as beer and curry, there can be no finer place in a central location
than Husband Bosworth - just south of Leicester.  They have a great cafe and
a great welcome (and provide fuel).  It is marked as a gliding site, but
they also accept microlights and VLA. We were greeted very warmly, and the
symmetry of our GT450 wings was admired ... we avoided their winch wires,
always a good idea, and I had the best scampi & chips I've enjoyed in a long
time.  Full marks all round.

So why not a Meet there?  Of course, Sywell is straight out of a "Hercule
Periot" programme, and there's everything there an aviator wants ...

Answers on a postcard ...

Marilyn

#97579 From: "Marilyn" <m@...>
Date: Thu Dec 10, 2009 6:24 pm
Subject: Re: A change from aggro, a ray of Christmas Sunshine....
nmarilyn95
Offline Offline
Send Email Send Email
 
That note was written for stuffing in Christmas cards to the uninitiated.  Many
thanks so many liked it - you are all great.

As far as beer and curry, there can be no finer place in a central location than
Husband Bosworth - just south of Leicester.  They have a great cafe and a great
welcome (and provide fuel).  It is marked as a gliding site, but they also
accept microlights and VLA. We were greeted very warmly, and the symmetry of our
GT450 wings was admired ... we avoided their winch wires, always a good idea,
and I had the best scampi & chips I've enjoyed in a long time.  Full marks all
round.

So why not a Meet there?  Of course, Sywell is straight out of a "Hercule
Periot" programme, and there's everything there an aviator wants ...

Answers on a postcard ...

Marilyn

--- In microlights@yahoogroups.com, John Moore <cyberstitchuk@...> wrote:
>
> One could soon be put together for January...
>
> Thoughts?
>
> On 10 Dec 2009, at 17:21, Kev A wrote:
>
> > Paul Millen" <flying@> wrote:
> >
> > > PS I've got an idea! Why don't some of us meet up for beer and
> > curry..... or
> > > has that been done? ;-)) Happy days!
> >
> > *Great Idea Paul; why stop at once a year? Suggestions welcome.
> > Maybe we should have a microlighter's Xmas do; it would at least
> > take the taste away of all the wrangling at the AGM ;-)
> >
> > >
> > >
> > > -----Original Message-----
> > > From: microlights@yahoogroups.com [mailto:microlights@yahoogroups.com
> > ] On
> > > Behalf Of Kev A
> > > Sent: 10 December 2009 16:52
> > > To: microlights@yahoogroups.com
> > > Subject: [microlights] A change from aggro, a ray of Christmas
> > Sunshine....
> > >
> > > Got this note from Marilyn Nichols, it was so good, I've forwarded
> > it to
> > > you; she's a thproughly pleasant little lady in her mid fifties
> > and livelier
> > > than a Flexwing in summer thermals; Bill went on a Rotax course on
> > Saturday
> > > and Ms Nichols was disappointed there wasn't a place for her,
> > which says it
> > > all.
> > >
> > > Hope you enjoy reading it as much as I did
> > > Kev
> > >
> > > Original MessageFrom: Marilyn Nichols
> > > [mailto:member@]
> > >
> > > Some movies (and music) distill the pivotal truths in our lives.
> > In American
> > > Beauty, the protagonist says "I feel as if I'm waking from a long
> > time in a
> > > coma". Apologies to my children, who I would never wish away, but
> > I am
> > > liberated; emerging from 25 years of responsible parenthood and
> > ushered into
> > > the next Age of Man when the time ahead is so pregnant with
> > possibility.
> > >
> > > >clip
> > >
> >
> >
> >
>
>
>
> [Non-text portions of this message have been removed]
>

#97578 From: John Moore <cyberstitchuk@...>
Date: Thu Dec 10, 2009 5:34 pm
Subject: Re: Re: A change from aggro, a ray of Christmas Sunshine....
big_john_baxby
Offline Offline
Send Email Send Email
 
One could soon be put together for January...

Thoughts?

On 10 Dec 2009, at 17:21, Kev A wrote:

> Paul Millen" <flying@...> wrote:
>
> > PS I've got an idea! Why don't some of us meet up for beer and
> curry..... or
> > has that been done? ;-)) Happy days!
>
> *Great Idea Paul; why stop at once a year? Suggestions welcome.
> Maybe we should have a microlighter's Xmas do; it would at least
> take the taste away of all the wrangling at the AGM ;-)
>
> >
> >
> > -----Original Message-----
> > From: microlights@yahoogroups.com [mailto:microlights@yahoogroups.com
> ] On
> > Behalf Of Kev A
> > Sent: 10 December 2009 16:52
> > To: microlights@yahoogroups.com
> > Subject: [microlights] A change from aggro, a ray of Christmas
> Sunshine....
> >
> > Got this note from Marilyn Nichols, it was so good, I've forwarded
> it to
> > you; she's a thproughly pleasant little lady in her mid fifties
> and livelier
> > than a Flexwing in summer thermals; Bill went on a Rotax course on
> Saturday
> > and Ms Nichols was disappointed there wasn't a place for her,
> which says it
> > all.
> >
> > Hope you enjoy reading it as much as I did
> > Kev
> >
> > Original MessageFrom: Marilyn Nichols
> > [mailto:member@...]
> >
> > Some movies (and music) distill the pivotal truths in our lives.
> In American
> > Beauty, the protagonist says "I feel as if I'm waking from a long
> time in a
> > coma". Apologies to my children, who I would never wish away, but
> I am
> > liberated; emerging from 25 years of responsible parenthood and
> ushered into
> > the next Age of Man when the time ahead is so pregnant with
> possibility.
> >
> > >clip
> >
>
>
>



[Non-text portions of this message have been removed]

#97577 From: "roger h" <fatcharlie@...>
Date: Thu Dec 10, 2009 5:26 pm
Subject: Re: A change from aggro, a ray of Christmas Sunshine....
fatcharlieuk
Offline Offline
Send Email Send Email
 
Jeez sometimes I wish I still lived in the UK - I haven't been able to find that
mentality over here yet :-(

--- In microlights@yahoogroups.com, "Kev A" <kevin@...> wrote:
>
> Paul Millen" <flying@> wrote:
>
> > PS I've got an idea! Why don't some of us meet up for beer and curry..... or
> > has that been done? ;-)) Happy days!
>
> *Great Idea Paul; why stop at once a year? Suggestions welcome. Maybe we
should have a microlighter's Xmas do; it would at least take the taste away of
all the wrangling at the AGM ;-)
>
> >
> >
> > -----Original Message-----
> > From: microlights@yahoogroups.com [mailto:microlights@yahoogroups.com] On
> > Behalf Of Kev A
> > Sent: 10 December 2009 16:52
> > To: microlights@yahoogroups.com
> > Subject: [microlights] A change from aggro, a ray of Christmas Sunshine....
> >
> > Got this note from Marilyn Nichols, it was so good, I've forwarded it to
> > you; she's a thproughly pleasant little lady in her mid fifties and livelier
> > than a Flexwing in summer thermals; Bill went on a Rotax course on Saturday
> > and Ms Nichols was disappointed there wasn't a place for her, which says it
> > all.
> >
> > Hope you enjoy reading it as much as I did
> > Kev
> >
> > Original MessageFrom: Marilyn Nichols
> > [mailto:member@]
> >
> > Some movies (and music) distill the pivotal truths in our lives. In American
> > Beauty, the protagonist says "I feel as if I'm waking from a long time in a
> > coma". Apologies to my children, who I would never wish away, but I am
> > liberated; emerging from 25 years of responsible parenthood and ushered into
> > the next Age of Man when the time ahead is so pregnant with possibility.
> >
> > >clip
> >
>

#97576 From: "Kev A" <kevin@...>
Date: Thu Dec 10, 2009 5:21 pm
Subject: Re: A change from aggro, a ray of Christmas Sunshine....
factoryfit
Offline Offline
Send Email Send Email
 
Paul Millen" <flying@...> wrote:

> PS I've got an idea! Why don't some of us meet up for beer and curry..... or
> has that been done? ;-)) Happy days!

*Great Idea Paul; why stop at once a year? Suggestions welcome. Maybe we should
have a microlighter's Xmas do; it would at least take the taste away of all the
wrangling at the AGM ;-)

>
>
> -----Original Message-----
> From: microlights@yahoogroups.com [mailto:microlights@yahoogroups.com] On
> Behalf Of Kev A
> Sent: 10 December 2009 16:52
> To: microlights@yahoogroups.com
> Subject: [microlights] A change from aggro, a ray of Christmas Sunshine....
>
> Got this note from Marilyn Nichols, it was so good, I've forwarded it to
> you; she's a thproughly pleasant little lady in her mid fifties and livelier
> than a Flexwing in summer thermals; Bill went on a Rotax course on Saturday
> and Ms Nichols was disappointed there wasn't a place for her, which says it
> all.
>
> Hope you enjoy reading it as much as I did
> Kev
>
> Original MessageFrom: Marilyn Nichols
> [mailto:member@...]
>
> Some movies (and music) distill the pivotal truths in our lives. In American
> Beauty, the protagonist says "I feel as if I'm waking from a long time in a
> coma". Apologies to my children, who I would never wish away, but I am
> liberated; emerging from 25 years of responsible parenthood and ushered into
> the next Age of Man when the time ahead is so pregnant with possibility.
>
> >clip
>

#97575 From: "Paul Millen" <flying@...>
Date: Thu Dec 10, 2009 5:13 pm
Subject: RE: A change from aggro, a ray of Christmas Sunshine....
paul_millen
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Brought a tear to my eye, that did!

Made the group feel just like the old days, before the Troll fest.

Marilyn, you're gonna LOVE Scotland. No, REALLY!!

Paul

PS I've got an idea! Why don't some of us meet up for beer and curry..... or
has that been done? ;-)) Happy days!


-----Original Message-----
From: microlights@yahoogroups.com [mailto:microlights@yahoogroups.com] On
Behalf Of Kev A
Sent: 10 December 2009 16:52
To: microlights@yahoogroups.com
Subject: [microlights] A change from aggro, a ray of Christmas Sunshine....

Got this note from Marilyn Nichols, it was so good, I've forwarded it to
you; she's a thproughly pleasant little lady in her mid fifties and livelier
than a Flexwing in summer thermals; Bill went on a Rotax course on Saturday
and Ms Nichols was disappointed there wasn't a place for her, which says it
all.

Hope you enjoy reading it as much as I did
Kev

Original MessageFrom: Marilyn Nichols
[mailto:member@...]

Some movies (and music) distill the pivotal truths in our lives. In American
Beauty, the protagonist says "I feel as if I'm waking from a long time in a
coma". Apologies to my children, who I would never wish away, but I am
liberated; emerging from 25 years of responsible parenthood and ushered into
the next Age of Man when the time ahead is so pregnant with possibility.

>clip

#97574 From: "roger h" <fatcharlie@...>
Date: Thu Dec 10, 2009 4:58 pm
Subject: Re: A change from aggro, a ray of Christmas Sunshine....
fatcharlieuk
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Way to go, Marilyn.

#97573 From: "Kev A" <kevin@...>
Date: Thu Dec 10, 2009 4:52 pm
Subject: A change from aggro, a ray of Christmas Sunshine....
factoryfit
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Send Email Send Email
 
Got this note from Marilyn Nichols, it was so good, I've forwarded it to you;
she's a thproughly pleasant little lady in her mid fifties and livelier than a
Flexwing in summer thermals; Bill went on a Rotax course on Saturday and Ms
Nichols was disappointed there wasn't a place for her, which says it all.

Hope you enjoy reading it as much as I did
Kev

Original MessageFrom: Marilyn Nichols
[mailto:member@...]

Some movies (and music) distill the pivotal truths in our lives. In American
Beauty, the protagonist says "I feel as if I'm waking from a long time in a
coma". Apologies to my children, who I would never wish away, but I am
liberated; emerging from 25 years of responsible parenthood and ushered into the
next Age of Man when the time ahead is so pregnant with possibility.

We've seized that thought with both hands - rushed to an airfield, earned a
flying license, bought a flex wing microlight, and joined the crazy group of
(mostly) men who appear to soar lazily in skies near you. We've had a great time
in 2009 with our flying - highs and lows quite literally - living the truth that
once you've a license is when the learning begins. No bruises or personal
injuries to show for the bumpy road of experience - a few insurance claims - but
fibreglass and alloyed metals are endlessly renewable.

I've never won the lottery, but even that oft quoted vision of good luck
couldn't improve the feeling of elation I have when settling into the front seat
of a flexwing. There are rules of the air and restricted airspace to avoid, but
the tyranny of gravity and life as an ant falls away: adopt a heading, a point
in the far horizon and head for it, even better with the wind at your back.
Navigation has nabbed me: I'd much rather draw lines on a chart, identify
waypoints and landmarks, factor in wind strength and direction than rely on the
GPS. Not so my pilot who likes the toy airplane superimposed on the GPS map. My
finger anticipates railway lines, reservoirs, motorways, hills and radio masts
under our flight path along the aviation chart.

We are the ideal mix - splitting the executive workload of a flight between us -
especially as I am still on the path towards my license. I've come to an
acceptance that the unfeminine things like engine maintenance and preflight
checks are my responsibility too if I am to assume the position of P1 in 2010.
My radio license is firmly under my belt - good thing as Bill dislikes this
aspect. "Carlisle Approach, Microlight Golf Charlie Echo Brava Delta"
on a bright July day - what could be better?

Recreational flying has opened up a wide horizon of experience - new friends and
acquaintances, a much more intimate knowledge of the landscape of these islands,
a great fillip to our self esteem - learning the theory of flight, meteorology,
navigation, etc. The old dog CAN be taught! It is good for the little grey cells
to soar high above the earthly cares and suspend time. The high and mighty
behind their impregnable walls lose their privacy, as we circle above their
estates, looking at the tennis courts and the extent of their private empires.

Matt loves flying with his dad, but seems to have a curse - as each time he dons
the helmet, visibility decreases and winds increase. All the teenagers of
Bakewell are interested in what's in the air now, and recognise our wing as it
traverses the skies over them. The news of our new activity is well known
locally, surprisingly. It sure beats milking cows each end of the day!

There's no disguising my joy at every clear skied dawn - and several B&B guests
have been ushered unceremoniously down the drive as we want to go flying! A few
have been left waiting on the doorstep for us to return from the Northumberland
coast. We have come full circle - back to the irresponsible teenager, all too
eager to abandon our post in favour of unadulterated fun. No lingering sense of
guilt there - I've done my time - the west coast of Scotland beckons in 2010 and
if you're lucky, I'll send you a video attached to an e mail. That's a modern
baby-boomer, wishing you all - a merry Christmas!

Marilyn

#97572 From: John Moore <cyberstitchuk@...>
Date: Thu Dec 10, 2009 4:29 pm
Subject: Re: Re: Spamfield stickers
big_john_baxby
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I have just clipped my fee by 20% :o)

The stickers were sourced locally.  I have now purchased them from
abroad.

UK price is 500 for 70p each (plus vat).  I have just bought 1000 for
10p but I dont need that many - just 500.. so price of 25p is circa
what it is.

You want to buy 500 cheap Spammers stickers, Mike?  Would make a good
repair for your tatty wing?

BJ


On 10 Dec 2009, at 10:19, Mike wrote:

> How come everything next year is half the price of this year was it
> overpriced in the first place ? very nice that it is but i would
> like to know why
>
> Mike
>
> --- In microlights@yahoogroups.com, John Moore <cyberstitchuk@...>
> wrote:
> >
> > Stickers..
> >
> > Last year 70p each.. this year 25p each.
> >
> > Bonus :-)
> >
> > 500 cloth badges this year too :-)
> >
>
>
>



[Non-text portions of this message have been removed]

#97571 From: "Kev A" <kevin@...>
Date: Thu Dec 10, 2009 2:37 pm
Subject: Re: engine weights
factoryfit
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wallyhayward" <goldbar@...> wrote:

> I might say that I have been quite happy with the Ivo on my Shadow and it is
so simple to adjust pitch to set it up.

*The Ivo is the bee's knees to adjust, but I've some info that might also be
worth chewing over:-

On my little 447 single seater it came with a 1450 3 blade Arplast, which I took
for granted until a bag of sweets went through the prop (don't ask) and the
harder ones (Chewits I believe, the Flumps did no harm at all) took the leading
edges off. Sent it back to Lyndhurst for repair at SAR Helice in France which
took a few weeks.

So as a friend was in the US he kindly brought back an Ivo, cheap. Noise
certificate was no problem to get based on a quick discussion with the CAA, who
were most pragmatic, and classed it as if it was any other composite three
blader.

Once that arrived on it went. I couldn't wait to get rid of it. The engine
spooled up much more slowly, noise was worse, and fuel consumption went up by a
litre or two. More throttle was needed for the same level cruise no matter what
I did with the pitch.

It also flapped around a lot more on startup than the Arplast.

Cheers

Kev

#97570 From: "bob_hood_uk" <bobhood@...>
Date: Thu Dec 10, 2009 2:27 pm
Subject: Re: engine weights
bob_hood_uk
Offline Offline
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--- In microlights@yahoogroups.com, "Kev A" <kevin@...> wrote:
>
> More I think about this, the more attractive a lighter propeller becomes; I
was surprised P&M fitted an Ivo to their SSDR trike; hardly the lightest make
around with those chrome-moly steel rods down each blade.
>
> Cheers
>
> Kev
>

Bob chips in,

Kev, I think that cost had more to do with it than weight. However, the Ivo (if
fitted with the quick adjust hub) is much easier to adjust than the Arplast, and
can be matched to the engine output very easily. This is ideal for an SSDR
machine, as the pitch isn't set in stone like it is for Section S machines.

Best regards,

Bob Hood.

#97569 From: "wallyhayward" <goldbar@...>
Date: Thu Dec 10, 2009 1:20 pm
Subject: Re: engine weights
wallyhayward
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Oooops. too many "wee drams" again:-)

Arplast figures should be
3 blade 3.5Kg
2 blade 2.7Kg


I might say that I have been quite happy with the Ivo on my Shadow and it is so
simple to adjust pitch to set it up.


As an aside Powerfins had been suffering from hub problems and de lamination
prior to the company stopping manufacture. To be fair the reason was the owner
"retired" and the new owner does intend to start manufacture again at some
point.


--- In microlights@yahoogroups.com, "Kev A" <kevin@...> wrote:
>
> *Wally, you're a star for digging all that up, I've been poking around for
ages for info. There's a typo on the Arplast figures, you list the two blade as
same weight as the three blade, any chance of the correction as I'm interested
please?
>
> Also the Arplast has tapered tips instead of the Warp and Ivos which have
paddle blades almost parallel out to the tip, so their moment of inertia is
higher than the weights would suggest.
>
> Only snag is the Arplast is fragile, for rough touring the Warp is the safer
bet, 60% heavier though!
>
> Kev
>
> wallyhayward" <goldbar@> wrote:
> > Unfortunately, I do not have any inertia values, but I have been looking at
different prop weights, generally for a 52" 3 blader which may give you some
ideas. The SAUR appearing the lightest at 2.6Kg 1.6m
> > 52" 3 blade Ivoprop 3.63Kg
> > 52" 2 blade 2.72Kg
> >
> > 52" 3 blade  Powerfin (manufacturing ceased, company sold)
> >  B model..3.34 Kg
> > C model    3.03 Kg
> >
> > Ultra Prop 3 blade 2.94Kg
> >
> > Saur Props 1.6m 2 blade 2.6Kg
> >
> > Kiev props 1.6m 3.7Kg
> >
> > Arplast 52" 3 blade 2.7Kg
> > 2 blade 2.7kgs.
> >
> > Warp Drive 52" 3 blade 4.1 to 4.3Kg
>

#97568 From: "Kev A" <kevin@...>
Date: Thu Dec 10, 2009 12:14 pm
Subject: Re: Engine weights
factoryfit
Offline Offline
Send Email Send Email
 
Paul Dewhurst wrote:
> These are all dry weights without rads exhaust, props etc for the fourstrokes
it seems.  certainly for the 912 add another 20kgs (we used 75kg for our load
tests)

*Worth adding this depends on layout; my Chaser had the huge silencer mounted
off the engine itself onto the frame struts below, which must substantially
reduce your test values?

Mainair silencers were hung directly off the side of the 503, although I suppose
this will have been handy in adding mass to damp out any shakes.

Swings and roundabouts, the new exhaust location and short, stubby header pipes
must provide some mass damping on the P&M 912 installation; at least they don't
shake themselves to bits like the early ones.

Did you note that Seaplane (Polish or Czech, can't recall) with a low mounted
912 with belt drive up to the prop to keep the CofG low? What a brave idea that
was; wonder if they made a blanking plate and pulley, or drove it straight off
the gearbox output flange?

Kev

#97567 From: "Kev A" <kevin@...>
Date: Thu Dec 10, 2009 11:28 am
Subject: Re: engine weights
factoryfit
Offline Offline
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*Wally, you're a star for digging all that up, I've been poking around for ages
for info. There's a typo on the Arplast figures, you list the two blade as same
weight as the three blade, any chance of the correction as I'm interested
please?

Also the Arplast has tapered tips instead of the Warp and Ivos which have paddle
blades almost parallel out to the tip, so their moment of inertia is higher than
the weights would suggest.

Only snag is the Arplast is fragile, for rough touring the Warp is the safer
bet, 60% heavier though!

Kev

wallyhayward" <goldbar@...> wrote:
> Unfortunately, I do not have any inertia values, but I have been looking at
different prop weights, generally for a 52" 3 blader which may give you some
ideas. The SAUR appearing the lightest at 2.6Kg 1.6m
> 52" 3 blade Ivoprop 3.63Kg
> 52" 2 blade 2.72Kg
>
> 52" 3 blade  Powerfin (manufacturing ceased, company sold)
>  B model..3.34 Kg
> C model    3.03 Kg
>
> Ultra Prop 3 blade 2.94Kg
>
> Saur Props 1.6m 2 blade 2.6Kg
>
> Kiev props 1.6m 3.7Kg
>
> Arplast 52" 3 blade 2.7Kg
> 2 blade 2.7kgs.
>
> Warp Drive 52" 3 blade 4.1 to 4.3Kg

#97566 From: <andy@...>
Date: Thu Dec 10, 2009 10:42 am
Subject: Re: Engine weights
andlard
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Send Email Send Email
 
There's a lots of different weights for all these motors, I guess the 'proof of
the pudding' is the full a/c weight and comparing similar a/c with the different
engine, or at least to one with a BMW motor, preferably the R1200. Lets hope one
day someone, maybe myself, gets the chance to try fitting one, I think thats the
only way we are going to find out whether its a real alternative or a bit of a
dud!
Still, I know you're out there to help me Paul!!!!
Regards
Andy

   ----- Original Message -----
   From: Paul Dewhurst
   To: microlights@yahoogroups.com
   Sent: Thursday, December 10, 2009 10:19 AM
   Subject: Re: [microlights] Engine weights



   These are all dry weights without rads exhaust, props etc for the fourstrokes
it seems. certainly for the 912 add another 20kgs (we used 75kg for our load
tests), whereas for the 582 ready to run it is 60Kg (and thats for C box and mag
end starter and oil injection - (E boxed Quantum premix version is slightly
less).

   So the difference in reality ready to go is rather larger than your weights
below suggest at first look.

   Paul
   ----- Original Message -----
   From: andy@...
   To: microlights@yahoogroups.com
   Sent: Wednesday, December 09, 2009 6:20 PM
   Subject: Re: [microlights] Engine weights

   To get in first and try and clear a few points:
   1) The 582 is a claimed 50kgs, the BMW R1150 is 68kgs, the R1200 is claimed to
be 3kgs lighter.
   2) 912 claimed to be 55kgs, the power from the R1200 can be mapped in the ECU
from 80 to 122hp.
   There are no R1200's I know of in use in a/c in the UK, it would be nice to
get the figures from the Europeans that are using it. Not being supported by the
factory is probably why statistics are so vague. The R1150 is in use.
   I understand the VW engine is quite heavy in comparisson.
   For more info try -
http://www.homebuiltairplanes.com/forums/firewall-forward-props-fuel-system/4659\
-bmw-r1200-motorcycle-engine-2.html
   Regards
   Andy

   ----- Original Message -----
   From: roger h
   To: microlights@yahoogroups.com
   Sent: Wednesday, December 09, 2009 2:45 PM
   Subject: [microlights] Engine weights

   To get back to a more sensible vein, thanks to all who have posted on this
subject - very interesting reading even though a lot of it started to go
straight over my head after about 5 posts!

   Would I be correct in summarising thus with regard to a BMW1200:

   1) Much heavier and less sprighty than a 582

   2) Around the same weight and a little less power than an unblown 912

   would that be a fair generalisation?

   What about in relation to a VW - particularly the 1800cc version? I'm thinking
a little lighter but quite a bit more poke - comments anyone?

   Thanks,

   Roger.

   [Non-text portions of this message have been removed]

   [Non-text portions of this message have been removed]





[Non-text portions of this message have been removed]

#97565 From: "roger h" <fatcharlie@...>
Date: Thu Dec 10, 2009 10:33 am
Subject: Re: Engine weights
fatcharlieuk
Offline Offline
Send Email Send Email
 
In the words of good old Homer Simpson, one of my lifetime heroes, "Why does
everything have to be so _difficult_??" Lol...

Wouldn't it be nice if, somewhere, there was a reference where one could go to
see how much they all weighed, ready to go?

Thanks Paul for the information provided.

I'm having a look at homebuilders.com as we speak - microlighters.co.za haven't
sent my forum confirmation yet but I hope to get some good stuff out of them.

Basically I'm a big bloke at 6'3" and rather heavier than I ought to be. I've
been looking at a few designs like the Clutton F.R.E.D. and Volksplanes but
worry about climb performance. It seems a BMW, possibly lighter and more
powerful than a VW1800cc might be a good conversion for this type of a/c.

I know they're not microlights, but I cannot find a 4-stroke 3-axis micro at a
price like these - mostly you can get one of the above for less than £5000. Even
if you add the price of changing the donkey, you still have a cheap, fun,
4-stroke beastie.

Cheers,

Roger.

--- In microlights@yahoogroups.com, "Paul Dewhurst" <paul@...> wrote:
>
> These are all dry weights without rads exhaust, props etc for the fourstrokes
it seems.  certainly for the 912 add another 20kgs (we used 75kg for our load
tests), whereas for the 582 ready to run it is 60Kg (and thats for C box and mag
end starter and oil injection - (E boxed Quantum premix version is slightly
less).
>
> So the difference in reality ready to go is rather larger than your weights
below suggest at first look.
>
> Paul
>   ----- Original Message -----
>   From: andy@...
>   To: microlights@yahoogroups.com
>   Sent: Wednesday, December 09, 2009 6:20 PM
>   Subject: Re: [microlights] Engine weights
>
>
>
>   To get in first and try and clear a few points:
>   1) The 582 is a claimed 50kgs, the BMW R1150 is 68kgs, the R1200 is claimed
to be 3kgs lighter.
>   2) 912 claimed to be 55kgs, the power from the R1200 can be mapped in the
ECU from 80 to 122hp.
>   There are no R1200's I know of in use in a/c in the UK, it would be nice to
get the figures from the Europeans that are using it. Not being supported by the
factory is probably why statistics are so vague. The R1150 is in use.
>   I understand the VW engine is quite heavy in comparisson.
>   For more info try -
http://www.homebuiltairplanes.com/forums/firewall-forward-props-fuel-system/4659\
-bmw-r1200-motorcycle-engine-2.html
>   Regards
>   Andy
>
>   ----- Original Message -----
>   From: roger h
>   To: microlights@yahoogroups.com
>   Sent: Wednesday, December 09, 2009 2:45 PM
>   Subject: [microlights] Engine weights
>
>   To get back to a more sensible vein, thanks to all who have posted on this
subject - very interesting reading even though a lot of it started to go
straight over my head after about 5 posts!
>
>   Would I be correct in summarising thus with regard to a BMW1200:
>
>   1) Much heavier and less sprighty than a 582
>
>   2) Around the same weight and a little less power than an unblown 912
>
>   would that be a fair generalisation?
>
>   What about in relation to a VW - particularly the 1800cc version? I'm
thinking a little lighter but quite a bit more poke - comments anyone?
>
>   Thanks,
>
>   Roger.
>
>   [Non-text portions of this message have been removed]
>
>
>
>
>
> [Non-text portions of this message have been removed]
>

#97564 From: "wallyhayward" <goldbar@...>
Date: Thu Dec 10, 2009 10:31 am
Subject: Re: engine weights
wallyhayward
Offline Offline
Send Email Send Email
 
Unfortunately, I do not have any inertia values, but I have been looking at
different prop weights, generally for a 52" 3 blader which may give you some
ideas. The SAUR appearing the lightest at 2.6Kg 1.6m

52" 3 blade Ivoprop 3.63Kg
52" 2 blade 2.72Kg

52" 3 blade  Powerfin (manufacturing ceased, company sold)
  B model..3.34 Kg
C model    3.03 Kg

Ultra Prop 3 blade 2.94Kg

Saur Props 1.6m 2 blade 2.6Kg

Kiev props 1.6m 3.7Kg

Arplast 52" 3 blade 2.7Kg
2 blade 2.7kgs.

Warp Drive 52" 3 blade 4.1 to 4.3Kg


--- In microlights@yahoogroups.com, "lauriehurman" <lauriehurman@...> wrote:
>
> When I was trying to get my Scorcher under 115Kg I tried taking the flywheel
off the 447 (over 2 Kg). I realised it wasn't going to work because of the
gearbox. As soon as you have a gearbox then you need an engine flywheel. If you
have direct drive then the prop can be as heavy as you want and it's acting as
the engine flywheel.
>
> Getting one thing to do two jobs is the way to get efficiency.
>
> Laurie (2)
> P.S. Back at Uni we used to learn to measure rotational inertia with the
"trifilar" experiment. Does anyone have a reference to this to save me trying to
work it out from scratch.
>
>
> --- In microlights@yahoogroups.com, "Kev A" <kevin@> wrote:
> >
> > Spot on Laurie, but handy to have some grunty load tests too, airliners have
crashed with lots of maths used in their design, and we mere toy 'plane flyers
are at least only need to demonstrate stresses do-able in a domestic garage.
> >
> > I'm more interested in another aspect:-
> >
> > If you take a lightweight engine and gearbox, then hook it up to a bloody
heavy prop, then the tail will wag the dog, so to speak, feedback more, and
shake the mounting around a lot harder. The engine and its mounting absorbs the
kickback by jumping around, instead of the prop speeding up and slowing down as
the pulses hit. Quiks used to have an Arplast prop fitted, they are light, a
little fragile, and very quiet and efficient. Big fan of those big fans;-)
> >
> > However now P&M have fitted the reliable, tough and heavy Warp Drive. It
would be interesting to see the different in rotational inertia. This isn't
always connected with overall weight, as heavier tips on a lighter prop will
give similar results to lighter tips on a heavier prop. Warps have broader tips
than Arplasts, and are solid carbon fibre, so may be worse than they might first
appear, anyone know the relative inertial values?
> >
> > Often wonder if Section S isn't comprehensive about this important detail,
it tends to look at cylinder numbers, two and four stroke, belt drive and so on;
it is good as it looks at shock and frequency of pulses per revolution.
> >
> > Maybe I'd best shut up, as it is hard enough to get a prop change approved
as it is, without being obliged also to look at the effect of a heavier prop on
airframe reliability...
> >
> > Kev
> >
> > --- In microlights@yahoogroups.com, "lauriehurman" <lauriehurman@> wrote:
> > >
> > > I'm going to speak up for sums.
> > >
> > > If you get a consultant to do you a decent FEA on your engine mount then
you will get more than a simple pass/fail. You will gain some understanding of
how the structure is working and how to improve it.
> > >
> > > Crucially you will also learn how the vibration of the engine is being fed
into the airframe - very valuable information.
> > >
> > > Laurie (2)
> > > No longer blue collar.
> > >
> > >
> > > --- In microlights@yahoogroups.com, "Paul Dewhurst" <paul@> wrote:
> > > >
> > > > Nope, nothings changed in my experience, we have never done an engine
mount by calculation, all we have done is by test.
> > > >
> > > > I often think that's where projects get bogged down. calculation is
always tricky and depends on many assumptions which can be tricky to
substantiate.
> > > >
> > > > We needed to test the engine mount on the Nynja as it has changed from
the Skyranger. We already had a simple frame that mimics the engine with a lever
on the Cg, and managed to complete the complete suite of engine mount load tests
in a morning. Now we could have spent 6 months doing sums and arguing about the
base assumptions and getting into deadlock, or worse still finding a fault in
the calcs later down the line (as I think has happened to the Trya), but for me
you would have to be a masochist to do that rather than a dead simple load test.
Calcs are for sissys - load tests with levers, winches and sandbags are for real
blue collar men :)
> > > >
> > > > If anyone wants to do this, then I am more than happy to let them have a
copy of one or more of our compliance test reports as a template and its a
simple matter of cutting and pasting for the individual installation.
> > > >
> > > > Paul
> > >
> >
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#97563 From: "Mike" <MIKEMICROMIKE@...>
Date: Thu Dec 10, 2009 10:19 am
Subject: Re: Spamfield stickers
micromikeuk
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How come everything next year is half the price of this year was it overpriced
in the first place ? very nice that it is but i would like to know why


Mike

--- In microlights@yahoogroups.com, John Moore <cyberstitchuk@...> wrote:
>
> Stickers..
>
> Last year 70p each.. this year 25p each.
>
> Bonus :-)
>
> 500 cloth badges this year too :-)
>

#97562 From: "Paul Dewhurst" <paul@...>
Date: Thu Dec 10, 2009 10:19 am
Subject: Re: Engine weights
flylight02
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These are all dry weights without rads exhaust, props etc for the fourstrokes it
seems.  certainly for the 912 add another 20kgs (we used 75kg for our load
tests), whereas for the 582 ready to run it is 60Kg (and thats for C box and mag
end starter and oil injection - (E boxed Quantum premix version is slightly
less).

So the difference in reality ready to go is rather larger than your weights
below suggest at first look.

Paul
   ----- Original Message -----
   From: andy@...
   To: microlights@yahoogroups.com
   Sent: Wednesday, December 09, 2009 6:20 PM
   Subject: Re: [microlights] Engine weights



   To get in first and try and clear a few points:
   1) The 582 is a claimed 50kgs, the BMW R1150 is 68kgs, the R1200 is claimed to
be 3kgs lighter.
   2) 912 claimed to be 55kgs, the power from the R1200 can be mapped in the ECU
from 80 to 122hp.
   There are no R1200's I know of in use in a/c in the UK, it would be nice to
get the figures from the Europeans that are using it. Not being supported by the
factory is probably why statistics are so vague. The R1150 is in use.
   I understand the VW engine is quite heavy in comparisson.
   For more info try -
http://www.homebuiltairplanes.com/forums/firewall-forward-props-fuel-system/4659\
-bmw-r1200-motorcycle-engine-2.html
   Regards
   Andy

   ----- Original Message -----
   From: roger h
   To: microlights@yahoogroups.com
   Sent: Wednesday, December 09, 2009 2:45 PM
   Subject: [microlights] Engine weights

   To get back to a more sensible vein, thanks to all who have posted on this
subject - very interesting reading even though a lot of it started to go
straight over my head after about 5 posts!

   Would I be correct in summarising thus with regard to a BMW1200:

   1) Much heavier and less sprighty than a 582

   2) Around the same weight and a little less power than an unblown 912

   would that be a fair generalisation?

   What about in relation to a VW - particularly the 1800cc version? I'm thinking
a little lighter but quite a bit more poke - comments anyone?

   Thanks,

   Roger.

   [Non-text portions of this message have been removed]





[Non-text portions of this message have been removed]

#97561 From: "Kev A" <kevin@...>
Date: Thu Dec 10, 2009 10:10 am
Subject: Re: engine weights
factoryfit
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lauriehurman" <lauriehurman@...> wrote:
Back at Uni we used to learn to measure rotational inertia with the "trifilar"
experiment. Does anyone have a reference to this to save me trying to work it
out from scratch.

Rotax give it here:-

http://www.rotax-owner.com/si_tb_info/serviceinfo/11ul91.pdf

More I think about this, the more attractive a lighter propeller becomes; I was
surprised P&M fitted an Ivo to their SSDR trike; hardly the lightest make around
with those chrome-moly steel rods down each blade.

Cheers

Kev

#97560 From: "lauriehurman" <lauriehurman@...>
Date: Thu Dec 10, 2009 8:59 am
Subject: Re: engine weights
lauriehurman
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When I was trying to get my Scorcher under 115Kg I tried taking the flywheel off
the 447 (over 2 Kg). I realised it wasn't going to work because of the gearbox.
As soon as you have a gearbox then you need an engine flywheel. If you have
direct drive then the prop can be as heavy as you want and it's acting as the
engine flywheel.

Getting one thing to do two jobs is the way to get efficiency.

Laurie (2)
P.S. Back at Uni we used to learn to measure rotational inertia with the
"trifilar" experiment. Does anyone have a reference to this to save me trying to
work it out from scratch.


--- In microlights@yahoogroups.com, "Kev A" <kevin@...> wrote:
>
> Spot on Laurie, but handy to have some grunty load tests too, airliners have
crashed with lots of maths used in their design, and we mere toy 'plane flyers
are at least only need to demonstrate stresses do-able in a domestic garage.
>
> I'm more interested in another aspect:-
>
> If you take a lightweight engine and gearbox, then hook it up to a bloody
heavy prop, then the tail will wag the dog, so to speak, feedback more, and
shake the mounting around a lot harder. The engine and its mounting absorbs the
kickback by jumping around, instead of the prop speeding up and slowing down as
the pulses hit. Quiks used to have an Arplast prop fitted, they are light, a
little fragile, and very quiet and efficient. Big fan of those big fans;-)
>
> However now P&M have fitted the reliable, tough and heavy Warp Drive. It would
be interesting to see the different in rotational inertia. This isn't always
connected with overall weight, as heavier tips on a lighter prop will give
similar results to lighter tips on a heavier prop. Warps have broader tips than
Arplasts, and are solid carbon fibre, so may be worse than they might first
appear, anyone know the relative inertial values?
>
> Often wonder if Section S isn't comprehensive about this important detail, it
tends to look at cylinder numbers, two and four stroke, belt drive and so on; it
is good as it looks at shock and frequency of pulses per revolution.
>
> Maybe I'd best shut up, as it is hard enough to get a prop change approved as
it is, without being obliged also to look at the effect of a heavier prop on
airframe reliability...
>
> Kev
>
> --- In microlights@yahoogroups.com, "lauriehurman" <lauriehurman@> wrote:
> >
> > I'm going to speak up for sums.
> >
> > If you get a consultant to do you a decent FEA on your engine mount then you
will get more than a simple pass/fail. You will gain some understanding of how
the structure is working and how to improve it.
> >
> > Crucially you will also learn how the vibration of the engine is being fed
into the airframe - very valuable information.
> >
> > Laurie (2)
> > No longer blue collar.
> >
> >
> > --- In microlights@yahoogroups.com, "Paul Dewhurst" <paul@> wrote:
> > >
> > > Nope, nothings changed in my experience, we have never done an engine
mount by calculation, all we have done is by test.
> > >
> > > I often think that's where projects get bogged down. calculation is always
tricky and depends on many assumptions which can be tricky to substantiate.
> > >
> > > We needed to test the engine mount on the Nynja as it has changed from the
Skyranger. We already had a simple frame that mimics the engine with a lever on
the Cg, and managed to complete the complete suite of engine mount load tests in
a morning. Now we could have spent 6 months doing sums and arguing about the
base assumptions and getting into deadlock, or worse still finding a fault in
the calcs later down the line (as I think has happened to the Trya), but for me
you would have to be a masochist to do that rather than a dead simple load test.
Calcs are for sissys - load tests with levers, winches and sandbags are for real
blue collar men :)
> > >
> > > If anyone wants to do this, then I am more than happy to let them have a
copy of one or more of our compliance test reports as a template and its a
simple matter of cutting and pasting for the individual installation.
> > >
> > > Paul
> >
>

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