X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=NIirBHyg c=1 sm=1 tr=0 a=XWSBf9a/bkSGQevdmJs33w==:117 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=x7bEGLp0ZPQA:10 a=ad1WmcueCrwA:10 a=oexKYjalfGEA:10 a=hOpmn2quAAAA:8 a=Ia-xEzejAAAA:8 a=HZJGGiqLAAAA:8 a=LeA3dly1waMmKubHC-gA:9 a=QEXdDO2ut3YA:10 a=rGB9wef-5JX2b8rUHxAA:9 a=8VVZoE2gL4kI0xFF:21 a=GyA-uvUxXSCciAkwuKQO:22 a=Urk15JJjZg1Xo0ryW_k8:22 From: "William Jepson wrjjrs@gmail.com" Received: from mail-ed1-f45.google.com ([209.85.208.45] verified) by logan.com (CommuniGate Pro SMTP 6.2.12) with ESMTPS id 12400845 for flyrotary@lancaironline.net; Tue, 02 Apr 2019 18:44:24 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.208.45; envelope-from=wrjjrs@gmail.com Received: by mail-ed1-f45.google.com with SMTP id a25so13116094edc.8 for ; Tue, 02 Apr 2019 15:44:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=QNnLL3qyjxnm3J+wlu9taKdnp2GSy+qypWiu4c47ARY=; b=paEKemxYcJmPDkpn0CRDIBlZWPqQMgzZ+8XQi+ZEZdEuw6HI1DcvbGhaGXljhDeAbY 2+ZMfRjWwdS3hnz2nN+PjJ7K1xnHSoWA2H+jwzEp47tuGlH7rfz0H3gtDCEw01WSX1ab SHHiYmJ8O0wxejUXnj72uDwIgVnJ3N/BtWcvI3qmNG+Xo/e6usdvaQr23rA9JNAXtrPa xUY9XXI7CZs66LTpHcig8hIOY4biIVBjpRldmcx6H3SI8mKatfS3v8G7TwJMXbQSBW3G VxxaQo2vQW5ccDiv/LI+19exQCd5skcdgUMVS/AqQmXYmYXCfQUT5n2L46NT/FCwWePv fKQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=QNnLL3qyjxnm3J+wlu9taKdnp2GSy+qypWiu4c47ARY=; b=QNXgMrW9mEer9bmLAbgSvL8ymLUzCCoUbzj3CQ3N2EDZN21LODXFHoUF2YdGIthwQ2 a5w6QmB2yL70ob1q5C9iIG6yGrdGyBu8V6JxaHFsVDQILTz1piI3au1gB965R/d/eD6R 1fdeBuRwynfYCBorjteKTukxvMhiO8ud5vlxVlWtqjIC9NSRBCXqf9FQhhy97F8QpozM /gaqNUKJYyF13oUjMVrFEcBqvHCF0BaCWre+C8XYUgr2CMRrzXFFAMvBDhHundDvE6oP IiqWyVLwE4an8MCi0sSc7qUZcMGH5nIfMAcgJtLakkVFoFAXu4l37yPSQ6aBpgCCXiS+ bGpA== X-Gm-Message-State: APjAAAXbUiKODK4Fa+aUht77JNjJ8/aKPuJKlRYmnC6tynrBV2itAVno /baTTcMsCTdqBZ6coU4zn24beA7r26KOeHgdgZIqEQ== X-Google-Smtp-Source: APXvYqzZTCLRl5LpepHmrhqFYO0YaJdbHZaBClGefjV9mbpI0eA5Y2eSM6EiSABPOyFQMJ93Dsg586tRUGLas2FgVCY= X-Received: by 2002:a50:9185:: with SMTP id g5mr26742197eda.225.1554245047127; Tue, 02 Apr 2019 15:44:07 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: Date: Tue, 2 Apr 2019 15:43:53 -0700 Message-ID: Subject: Re: [FlyRotary] Re: Electric constant speed props To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary="000000000000ed9538058593df81" --000000000000ed9538058593df81 Content-Type: text/plain; charset="UTF-8" Mark the thing that you need to consider is hp. A good p-port or blown rotary will make 200hp. If the LSA prop and hub are up to that it's a good option. The lighter the better. Bill Bill Jepson On Tue, Apr 2, 2019, 2:37 PM Marc Wiese cardmarc@charter.net < flyrotary@lancaironline.net> wrote: > There are composite CS electric props, they are showing up a lot on the > European LSA type planes lately. Whirlwind makes the blades? And MT Hoffman > make electric composite props too. A comp would weight much less, depending > on hub design. FWIW. > > Marc > > > > *From:* Rotary motors in aircraft > *Sent:* Tuesday, April 02, 2019 2:48 PM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: Electric constant speed props > > > > Sam, > > I am working with some originators of Powersport. The weight of your build > makes a big difference on the use of a constant speed. Also in the case of > the rotary the quality of your muffler! Sound levels really effect your > comfort on longer flights. Mufflers for rotaries are tough, I already have > 1 failed design to my (bad) credit. The original Powersport designs used > the light weight and flexibility of a wood prop to their advantage. Those > engines were tuned for max power at 6500 RPM. The reductions were about > 1.85 to 2.2:1. suitable for the lower power peak. Torsional vibration > issues also favored a wood prop. How heavy is the electric Airmaster? MOST > engines including the rotary are helped by a variable pitch prop. Whether > the combination is safe depends on the reduction drive, ratio, and weight > of the prop on the output shaft. Powersport's owners noted significant > torsional vibration problems with every planetary gear set, (even their own > custom made straight cut planetary). Their later stiff model internal ring > gear reduction gearbox put the resonances out of the normal range for the > rotary. Prior to that the only problem free build with a planetary was when > they built a pendulous damper system (like a big radial engine uses) which > worked great but was so expensive they figured they would never sell an > engine. So if you are running a planetary reduction you need to keep the > weight down as much as you can. Find out what the Airmaster weighs. The > amount that it exceeds your wood or carbon fixed blade prop is your risk > factor. The advantage is to use a low cruise rpm that takes advantage of > the props flexibility. As a thrust producing device it is better, there is > no doubt. If it is very heavy though it may cause problems that aren't > obvious as to origin. Torsional problems may take hundreds of hours to > develop, or something may break the first week. Just be wary. Always keep > track of things like changes in output shaft end play and backlash. You can > make the change, and see excellent results but go in with your eyes open. > Lots of people will tell you this is nervous nelly stuff, but the guys at > P.S. probably had more hours running and testing rotaries AT HIGH OUTPUT > levels than anyone other than Mazda. > > Bill Jepson > > > > On Tue, Apr 2, 2019 at 6:34 AM Samuel Hodges samueln462wp@att.net < > flyrotary@lancaironline.net> wrote: > > Lately I have been considering an Airmaster electric constant speed prop > to help achieve the rotaries true potential. I am asking for insight to > help me make this decision. I'm not sure if the benefits of a constant > speed out weight the cost, please help. > > > > Sam > > RV-7A > > Renesis > > --000000000000ed9538058593df81 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Mark the thing that you need to consider is hp. A good p-= port or blown rotary will make 200hp. If the LSA prop and hub are up to tha= t it's a good option. The lighter the=C2=A0better.
Bil= l

Bill Jepson

On Tue, Apr 2, 2019, 2:37 PM Marc Wiese cardmarc@charter.net <flyrotary@lancaironline.net> wrote:
=

There are composite CS electric= props, they are showing up a lot on the European LSA type planes lately. W= hirlwind makes the blades? And MT Hoffman make electric composite props too= . A comp would weight much less, depending on hub design. FWIW.

Marc

=C2=A0

From: Rotary motors in aircraft <flyrotary@la= ncaironline.net>
Sent: Tuesday, April 02, 2019 2:48 PMTo: Rotary motors in aircraft <flyrotary@lancaironline.= net>
Subject: [FlyRotary] Re: Electric constant speed prop= s

=C2=A0

Sam,

I am w= orking with some originators of Powersport. The weight of your build makes = a big difference on the use of a constant speed. Also in the case of the ro= tary the quality of your muffler! Sound levels really effect your comfort o= n longer flights. Mufflers for rotaries are tough, I already have 1 failed = design to my (bad) credit. The original Powersport designs used the light w= eight and flexibility of a wood prop to their advantage. Those engines were= tuned for max power at 6500 RPM. The reductions were about 1.85 to 2.2:1. = suitable for the lower power peak. Torsional vibration issues also favored = a wood prop. How heavy is the electric Airmaster? MOST engines including th= e rotary are helped by a variable pitch prop. Whether the combination is sa= fe depends on the reduction drive, ratio, and weight of the prop on the out= put shaft. Powersport's owners noted significant torsional vibration pr= oblems with every planetary gear set, (even their own custom made straight = cut planetary). Their later stiff model internal ring gear reduction gearbo= x put the resonances out of the normal range for the rotary. Prior to that = the only problem free build with a planetary was when they built a pendulou= s damper system (like a big radial engine uses) which worked great but was = so expensive they figured they would never sell an engine. So if you are ru= nning a planetary reduction you need to keep the weight down as much as you= can. Find out what the Airmaster weighs. The amount that it exceeds your w= ood or carbon fixed blade prop is your risk factor. The advantage is to use= a low cruise rpm that takes advantage of the props flexibility. As a thrus= t producing device it is better, there is no doubt. If it is very heavy tho= ugh it may cause problems that aren't obvious as to origin. Torsional p= roblems may take hundreds of hours to develop, or something may break the f= irst week. Just be wary. Always keep track of things like changes in output= shaft end play and backlash. You can make the change, and see excellent re= sults but go in with your eyes open. Lots of people will tell you this is n= ervous nelly stuff, but the guys at P.S. probably had more hours running an= d testing rotaries AT HIGH OUTPUT levels than anyone other than Mazda.

Bill Jepson

=C2=A0

On Tue, Apr 2, 2019 at 6:34 AM Samuel Hodges samueln462= wp@att.net <flyrotary@lancaironline.net> wrote:

=C2=A0Lately I have been considering a= n Airmaster electric constant speed prop to help achieve the rotaries true = potential. I am asking for insight to help me make this decision. I'm n= ot sure if the benefits of a constant speed out weight the cost, please hel= p.

=C2= =A0

Sam=

RV-7A<= /p>

Renesis=C2=A0<= /p>

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