X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ms-smtp-03.southeast.rr.com ([24.25.9.102] verified) by logan.com (CommuniGate Pro SMTP 5.1c.2) with ESMTP id 1228844 for flyrotary@lancaironline.net; Sat, 08 Jul 2006 11:58:51 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.102; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-111-186.carolina.res.rr.com [24.74.111.186]) by ms-smtp-03.southeast.rr.com (8.13.6/8.13.6) with SMTP id k68Fw3kr007483 for ; Sat, 8 Jul 2006 11:58:05 -0400 (EDT) Message-ID: <000901c6a2a7$50ebb2e0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Nothing to do with Rotary Engines, but.... Date: Sat, 8 Jul 2006 11:58:12 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0006_01C6A285.C981B9B0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2869 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0006_01C6A285.C981B9B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I would hazard a guess that Wendell is probably alluding to the better = energy conversion efficiency of an electric motor over an internal = combustion engine. Assuming the same energy input (whether in the from = of electricity or gasoline) a typical electric motor is around 50% = efficient where as the piston engine is around 25% efficient in = converting input energy to mechanical energy. So for the same energy = input an electric motor should give better conversion efficiency. So = you might get 100 HP out of a motor for a 200HP (electrical energy) = input - whereas to get 100 HP out of a piston engine you would need 400 = HP of energy input (in the form of gasoline) - the rest being "wasted" = in form of exhaust and cooling energy (and some friction). However, I agree with Jarret 1 HP =3D 1 HP regardless. =20 Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW ----- Original Message -----=20 From: Jarrett & Heidi Johnson=20 To: Rotary motors in aircraft=20 Sent: Saturday, July 08, 2006 11:48 AM Subject: [FlyRotary] Re: Nothing to do with Rotary Engines, but.... Wendel, I was always under the impression.. 1Hp was 1 Hp regardless of = how it was created.. =20 The only convertion's I've heard of were.. 1Hp=3D 2Dp [Donkey power] = , and 1Hp=3D1.5Mp [Mule power] :-) Jarrett ----- Original Message -----=20 From: Wendell Voto=20 To: Rotary motors in aircraft=20 Sent: Saturday, July 08, 2006 9:29 AM Subject: [FlyRotary] Re: Nothing to do with Rotary Engines, but.... What is the equivalent hp conversion of electric to gas engines? I'm = thinking it is about 2:1 (tried to look it up quickly, couldn't find = it), so instead of 180 hp, you would only need 90 hp electric. Wendell Subject: [FlyRotary] Re: Nothing to do with Rotary Engines, but.... Think about how small the alternators on big HP APU's are and you = get the picture on how small you can make a powerful electric motor if = you are willing to work at it a bit. You can easily make a 100 HP = electric motor that weighs 100 lbs. It would not likely be DC, however. = Electric motors for stationary use have no constraint on weight. = The only reason you would want to make one lighter would be to save on = materials and/or on shipping. If you make a motor of a given HP lighter, = it will cost more, spin faster, or be less efficient than the heavier = motor. If you are running on batteries, you must be careful not to save = weight on the motor by compromising efficiency, only to add to the total = vehicle weight by requiring more batteries to make up for the reduced = motor efficiency.=20 Bill Dube' george lendich wrote:=20 Hi Bill, I'm relieved. I won't have to mortgage the house until the technology advances enough to reduces the weight by a factor of 5. Currently it looks like I would need about 1400 lbs of batteries. Get it down to 280 lbs and allow 100 lbs for the electric motor and my W&B will work out about right. :) I'm looking forward to seeing what you come up with for the aircraft batteries. Bob W. =20 Bob or Bill I would have thought a 130hp DC Motor would weigh more than 100lbs. Any rule of thumb on weight of motor to power output ?- I guess there's = a lot of copper windings per HP!? George (down under) -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ =20 -------------------------------------------------------------------------= --- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.394 / Virus Database: 268.9.10/383 - Release Date: = 7/7/2006 ------=_NextPart_000_0006_01C6A285.C981B9B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I would hazard a guess that Wendell is probably = alluding=20 to the better energy conversion efficiency of an electric motor over an = internal=20 combustion engine.  Assuming the same energy input (whether in the = from of=20 electricity or gasoline) a typical electric motor is around 50% = efficient where=20 as the piston engine is around 25% efficient in converting input energy = to=20 mechanical energy.  So for the same energy input an electric motor = should=20 give better conversion efficiency.  So you might get 100 HP out of = a motor=20 for a 200HP (electrical energy) input - whereas to get 100 HP out of a = piston=20 engine you would need 400 HP of energy input (in the form of gasoline) - = the=20 rest being "wasted" in form of exhaust and cooling energy (and some=20 friction).
 
However, I agree with  Jarret 1 HP =3D = 1 HP=20 regardless. 
 
Ed
 
Ed Anderson
Rv-6A N494BW Rotary = Powered
Matthews,=20 NC
eanderson@carolina.rr.comhttp:/= /members.cox.net/rogersda/rotary/configs.htm#N494BW
----- Original Message -----
From:=20 Jarrett=20 & Heidi Johnson
Sent: Saturday, July 08, 2006 = 11:48=20 AM
Subject: [FlyRotary] Re: = Nothing to do=20 with Rotary Engines, but....

Wendel, I was always under the = impression.. 1Hp=20 was 1 Hp regardless of how it was created.. 
 
The only convertion's I've heard of = were.. =20 1Hp=3D 2Dp [Donkey power] , and 1Hp=3D1.5Mp [Mule power]  = :-)
 
Jarrett
----- Original Message -----
From:=20 Wendell Voto=20
To: Rotary motors in = aircraft=20
Sent: Saturday, July 08, 2006 = 9:29=20 AM
Subject: [FlyRotary] Re: = Nothing to do=20 with Rotary Engines, but....

What is the equivalent hp conversion of electric to gas = engines? I'm=20 thinking it is about 2:1 (tried to look it up quickly, couldn't find = it), so=20 instead of 180 hp, you would only need 90 hp electric.
 
Wendell
 
 
Subject: [FlyRotary] Re: Nothing to do with Rotary = Engines,=20 but....

Think about how small the alternators on big HP = APU's are=20 and you get the picture on how small you can make a powerful = electric=20 motor if you are willing to work at it a bit. You can easily make = a 100 HP=20 electric motor that weighs 100 lbs. It would not likely be DC,=20 however. 

Electric motors for stationary use have no=20 constraint on weight. The only reason you would want to make one = lighter=20 would be to save on materials and/or on shipping. If you make a = motor of a=20 given HP lighter, it will cost more, spin faster, or be less = efficient=20 than the heavier motor. If you are running on batteries, you must = be=20 careful not to save weight on the motor by compromising = efficiency, only=20 to add to the total vehicle weight by requiring more batteries to = make up=20 for the reduced motor efficiency.

Bill Dube'

george = lendich=20 wrote:=20 
Hi Bill,

I'm relieved.  I won't have to mortgage the house until the technology
advances enough to reduces the weight by a factor of 5. Currently it
looks like I would need about 1400 lbs of batteries.  Get it down to
280 lbs and allow 100 lbs for the electric motor and my W&B will =
work
out about right. :)

I'm looking forward to seeing what you come up with for the aircraft
batteries.

Bob W.
    

Bob or Bill
I would have thought a 130hp DC Motor  would weigh more than 100lbs.
Any rule of thumb on weight of motor to power output ?- I guess there's =
a
lot of copper windings per HP!?
George (down under)



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Homepage:  http://www.flyrotary.com/
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No virus found in this incoming message.
Checked by AVG = Free=20 Edition.
Version: 7.1.394 / Virus Database: 268.9.10/383 - = Release Date:=20 7/7/2006
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