X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=dLzYZ9Rb c=1 sm=1 tr=0 a=OlrVMwvYqn8kuyynXNqZZg==:117 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=x7bEGLp0ZPQA:10 a=DxjPifHaizMA:10 a=oexKYjalfGEA:10 a=pGLkceISAAAA:8 a=Ia-xEzejAAAA:8 a=HZJGGiqLAAAA:8 a=UKPAHat8AAAA:8 a=IPRctrZpx8Fxsxy4j7kA:9 a=O4n-GvsIrNheX8iM:21 a=SMSWXxvpNFaTYR0P:21 a=QEXdDO2ut3YA:10 a=viRuYi0F0g6aZunuKf8A:9 a=5jIeITifv7RRa-ss:21 a=p57R0P2Xpv3wKt5W:21 a=zKPvwLdRbneHjfix:21 a=Urk15JJjZg1Xo0ryW_k8:22 a=Fc6xXSS-RxGHxrvp76Qp:22 From: "James Whitehurst flyboyusvi@gmail.com" Received: from mail-wm1-f48.google.com ([209.85.128.48] verified) by logan.com (CommuniGate Pro SMTP 6.2.12) with ESMTPS id 12430221 for flyrotary@lancaironline.net; Mon, 08 Apr 2019 10:27:58 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.128.48; envelope-from=flyboyusvi@gmail.com Received: by mail-wm1-f48.google.com with SMTP id w15so14963941wmc.3 for ; Mon, 08 Apr 2019 07:27:59 -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=DBvdzr+hTvVzOxIEUXyawsk+no2EhMPWFQqHYoJ/YAA=; b=hlQA3sH4VSmEbhD3VqSfqr4NbmVjqgELFqYfS2fJ8MUUZ+aA4uC3DoX2i6dx4GyF7p noUrxPywx2nJjns+uOTZuvqYtk5GVs0ZNZNxQZaOyIOBaSK2RKmIKJjOIgTZg9l8OJUD HJjWP/VOy0Gh2ryGT08RxttBN2imH+vCTnrZ7qn7LODNKaDjmVN+B484ZBLto3zzh0ER Z/SFCgbRa/BUK1HirebVK1cEj7VG587xnzoqQPDs9ojgJcOq6jQgsH/WXqiO7tPOhE5S Ah+pIfLfq0vyIjoAYIJHOAUaq38/KHcNB8lvckhNcrW9JD0UovvcQ6OqPNveH8A/7rjK /F7w== 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=DBvdzr+hTvVzOxIEUXyawsk+no2EhMPWFQqHYoJ/YAA=; b=OWKT82ERAMTuvDEWBNbzkJmGtD15FxaEG9zZvgjyCFpE3uh7UiXEufCpfGxll91KtC Zu8vVIFM50StV+B1wasYxlfurWtMGZcVPs6lLZ29ekhDra3PAdchi/g9t1VDY9JgDfMA miTb44Mvj0rzrSoz+07bAmbm5+GOhRxP/ycv6uCyBDNCTjCi9bVS/CDOFaiASuoNUAzd RGum2HL4aO+z0uC9TxsqMNmMd39/5kZjItUfaCnrOCZrqOe3Fg+zxmZdDh4FtMtGHUt7 fp32Hu/VYq8rzhmZQ2PDzIyw+/frsPxxS1yTYJLdkq3KOhqLnynVp1TmL0GX5UNWiM5e y36g== X-Gm-Message-State: APjAAAUh78mGAZLjmfDarpgjald2CY6FmQVjJfCs030raq5utSpaDWZF Iq03kCMQVs2t2TfOFgHsTDDjZ4XP2RSyxFxAnZL3BstH X-Google-Smtp-Source: APXvYqwYC9ktL+9K/W53ZIX6SJEsMttBeif1wSNLI2QWG4GFsYzg1Lbhnka+lgwi9FDYOC5BHIS4KkSBbTk7KEmfjyk= X-Received: by 2002:a7b:cb04:: with SMTP id u4mr18992462wmj.0.1554733658678; Mon, 08 Apr 2019 07:27:38 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: Date: Mon, 8 Apr 2019 10:22:15 -0400 Message-ID: Subject: Re: [FlyRotary] Re: Electric constant speed props To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary="0000000000007228fc058605a364" --0000000000007228fc058605a364 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi guys, I just spoke with Martin of Airmaster at Sun n Fun. He seems to be one of the main engineers(very knowledgable). I asked him if he could make me 2, C/S, electric, reversible, feathering props for my twin 350 hp rotary amphibian. The bottom line is yes, 5 blade to absorb the hp, about45#, around the same price as my MT quote but they will have to work out the details of my operational control requirements over the next few months.( I am at least 2 years from needing the props.) Electric seems to be where I am headed unless someone out there knows where I can get 2 Mistral PSRU's. James whitehurst On Fri, Apr 5, 2019, 21:14 Charlie England ceengland7@gmail.com < flyrotary@lancaironline.net> wrote: > Well, now I know that I should proof read before hitting send.... > > On 4/5/2019 3:46 PM, Charlie England ceengland7@gmail.com wrote: > > I had a similar experience with one of the guys with AutoPSRUs in the alt > engine tent a couple of years ago. Tried to sell me a reduction for a > rotary, and it was blatantly obvious that he was clueless. But their whol= e > concept has major flaws, so I shouldn't have been surprised. > > As a FWIW, if you're serious about a controllable prop it might be worth > finding someone else in the company to question. My experience at airshow= s > in general is that you might get the CEO, or you might get a guy that's > filling in for his friend who went to take a leak. :-) I know, because > about 25 years ago, I was occasionally that guy on occasion. :-) > > Charlie > > On 4/5/2019 8:47 AM, Samuel Hodges samueln462wp@att.net wrote: > > Went to Sun n Fun and talked to a Aeromaster representative to collect > information and data on their Electric constant speed prop combinations. > After waiting a little while a representative of the company approached a= s > asked what he can do for me. I replied that I am extremely interested in > their design and would like further information. I was asked about my > aircraft engine installation, I explained to him about the Rotary and wha= t > my RPM requirements would be. His response went something like this " Do > you know how much this cost? it will probably double the cost of your > installation/plane" I immediately took this as an insult and replied " yo= u > know nothing of me, my finances, nor my plane" as I walked past him I > padded him on the arm and said " keep your freakin prop, you just saved m= e > a lot of money" but I didn't say freakin. One thing I did find out is tha= t > it would be around 26lbs, well worth the trip, wouldn't you agree? > > Sam > > On Tuesday, April 2, 2019, 07:27:12 PM EDT, Bobby J. Hughes > bhughes@qnsi.net > wrote: > > > > Climb at 6800/ 2100 rpm > > Correction 6000/ 2100 rpm. > > Bobby > > Sent from my iPhone > > On Apr 2, 2019, at 5:46 PM, Bobby J. Hughes bhughes@qnsi.net < > flyrotary@lancaironline.net> wrote: > > Bill, > > Most takeoffs have been at 7000/2400 rpm with MP between 34-38=E2=80=9D t= o pattern. > Climb at 6800/ 2100 rpm > > Cruise at 5200/ 1824 or 4800/ 1624 rpm depending on my desired fuel burn > and airspeed. Most cross country flight are at 28-30=E2=80=9D MP and wit= h F/A > 15.8. Or 13.5 for higher MP. > > Bobby > > Sent from my iPhone > > On Apr 2, 2019, at 5:13 PM, William Jepson wrjjrs@gmail.com < > flyrotary@lancaironline.net> wrote: > > Bobby, You push it fairly hard with your supercharged engine too. What > cruise RPM are you running? P.Sport always tried to tune for lower RPMS a= nd > higher power to avoid the torsional vibration problems. With boost you ca= n > make more power at lower RPMs which is a plus in this case. The rotary i= s > tough, the engine will tolerate a lot, but the high revs for long periods > is what causes the need for attention to torsionals. BTW I moved and had = to > take a break from my redrive efforts, but am getting back to it. Got some > good ideas today from Mark Hatch, Everett's son. > Bill > > On Tue, Apr 2, 2019 at 2:02 PM Bobby J. Hughes bhughes@qnsi.net < > flyrotary@lancaironline.net> wrote: > > > My MT weighs 42#=E2=80=99s. The hub is heavy, blades are light weigh. Gea= r lashing > appears to have increased a little over the first 500 hours. End play is > about 5 thousandths with original snubber. > > Bobby > > Sent from my iPad > > On Apr 2, 2019, at 3:48 PM, William Jepson wrjjrs@gmail.com < > flyrotary@lancaironline.net> wrote: > > 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 effec= t > your comfort on longer flights. Mufflers for rotaries are tough, I alread= y > 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 vibrati= on > 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, an= d > 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 wi= th > 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 cruis= e > 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 en= d > 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 > > > > --0000000000007228fc058605a364 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi guys, I just spoke with Martin of Airmaster at Sun n F= un. He seems to be one of the main engineers(very knowledgable). I asked hi= m if he could make me 2, C/S, electric, reversible, feathering props for my= twin 350 hp rotary amphibian. The bottom line is yes, 5 blade to absorb th= e hp, about45#, around the same price as my MT quote=C2=A0 but they will ha= ve to work out the details of my operational control requirements over the = next few months.( I am at least 2 years from needing the props.) Electric s= eems to be where I am headed unless someone out there knows where I=C2=A0 c= an get 2 Mistral PSRU's. James whitehurst

On Fri, Apr 5, 2019, 21:14 Cha= rlie England ceengland7@gmail.com <flyrotary@lancaironli= ne.net> wrote:
=20 =20 =20
Well, now I know that I should proof read before hitting send....

On 4/5/2019 3:46 PM, Charlie England ceengland7@gmai= l.com wrote:
=20
I had a similar experience with one of the guys with AutoPSRUs in the alt engine tent a couple of years ago. Tried to sell me a reduction for a rotary, and it was blatantly obvious that he was clueless. But their whole concept has major flaws, so I shouldn't have been surprised.

As a FWIW, if you're serious about a controllable prop it might be worth finding someone else in the company to question. My experience at airshows in general is that you might get the CEO, or you might get a guy that's filling in for his friend who wen= t to take a leak. :-) I know, because about 25 years ago, I was occasionally that guy on occasion. :-)

Charlie

On 4/5/2019 8:47 AM, Samuel Hodges samueln462wp@at= t.net wrote:
=C2=A0Went to Sun n Fun and talked to a Aeromaster representative to collect information and data on their Electric constant speed prop combinations. After waiting a little while a representative of the company approached as asked what he can do for me. I replied that I am extremely interested in their design and would like further information. I was asked about my aircraft engine installation, I explained to him about the Rotary and what my RPM requirements would be. His response went something like this " Do you know how much this cost? it will probably double the cost of your installation/plane" I immediately took this as an insult and replied " you know nothing of me, my finances, nor my plane&= quot; as I walked past him I padded him on the arm and said " keep your freakin prop, you just saved me a lot of money" but I didn't say freakin. One thing I did find out is that it would be around 26lbs, well worth the trip, wouldn't you agree?

Sam =C2=A0 =C2=A0=C2=A0

On Tuesday, April 2, 2019, 07:27:12 PM EDT, Bobby J. Hughes bhughes@qnsi.net <flyrotary@lancaironline.net> wrote:



Climb at 6800/ 2100 rpm=C2=A0

Correction 6000/ 2100 rpm.=C2=A0

Bobby=C2=A0

Sent from my iPhone

On Apr 2, 2019, at 5:46 PM, Bobby J. Hughes bhughes@qnsi.net <flyrotary@lancaironli= ne.net> wrote:

Bill,

Most takeoffs have been at 7000/2400 rpm with MP between 34-38=E2=80=9D to pattern.
Climb at 6800/ 2100 rpm=C2=A0

Cruise at 5200/ 1824 or 4800/ 1624 rpm depending on my desired fuel burn and airspeed. =C2=A0Most cross country flight are at 28-30=E2=80= =9D MP and with F/A 15.8. Or 13.5 for higher MP.=C2=A0

Bobby

Sent from my iPhone

On Apr 2, 2019, at 5:13 PM, William Jepson wrjjrs@gmail.com <flyrotary@lanc= aironline.net> wrote:

Bobby, You push it fairly hard with your supercharged engine too. What cruise RPM are you running? P.Sport always tried to tune for lower RPMS and higher power to avoid the torsional vibration problems. With boost you can make more power at lower RPMs which is a plus in this case.=C2=A0 The rotary is toug= h, the engine will tolerate a lot, but the high revs for long periods is what causes the need for attention to torsionals. BTW I moved and had to take a break from my redrive efforts, but am getting back to it. Got some good ideas today from Mark Hatch, Everett's son.= =C2=A0
Bill

On Tue, Apr 2, 2019 at = 2:02 PM Bobby J. Hughes bhug= hes@qnsi.net <flyrotar= y@lancaironline.net> wrote:

My MT weighs 42#=E2=80=99s. The hu= b is heavy, blades are light weigh. Gear lashing appears to have increased a little over the first 500 hours. End play is about 5 thousandths with original snubber.=C2=A0

Bobby

Sent from my iPad

On Apr 2, 2019, at 3:48 PM, William Jepson wr= jjrs@gmail.com <flyrotary@lancaironli= ne.net> wrote:

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:
=C2=A0Lately 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=C2=A0


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