X-Virus-Scanned: clean according to Sophos on Logan.com From: "Tracy" Received: from mail-pa0-f54.google.com ([209.85.220.54] verified) by logan.com (CommuniGate Pro SMTP 6.1.5) with ESMTPS id 8002363 for flyrotary@lancaironline.net; Sat, 19 Sep 2015 21:35:37 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.220.54; envelope-from=rwstracy@gmail.com Received: by padhk3 with SMTP id hk3so83424396pad.3 for ; Sat, 19 Sep 2015 18:35:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:references:from:content-type:in-reply-to:message-id:date:to :content-transfer-encoding:mime-version; bh=5ErdSJy18fWGwf47ZdOHafSQLwMJtOKT25KcUIO8u7o=; b=gfuFZosd1gqkze/qyqEyS2eKYv0X4Ff9Cesu73FOlGuslIVnqKA5NBJSx6SxxebLSs i51SnWu90cmt7AtTkc62pKqEYwBcHfDfIbSupg2dVJfujsu72AFUTzOI638DHiNXuq9E 19oZ6oGYpb++UPQ46tlqWn2SxLIrqs0hIwGIhf5iD1mp6T3VwH/UyJeOszM2z/xYUza/ qkoDnNph8TlpsmQenokkEsscUS+avEjub+Yl1ivo/2AZ9Rmu+vshr+YeX6MQPwiyRdmc dwf1qHkYouCkRfMiis3desacd/f0uM5lhdh7SFKbtwyZqCXq/DomTn9Md2H5B3mb2HxK VAtw== X-Received: by 10.67.7.71 with SMTP id da7mr16012921pad.69.1442712903559; Sat, 19 Sep 2015 18:35:03 -0700 (PDT) Return-Path: Received: from [10.243.210.108] (36.sub-97-43-193.myvzw.com. [97.43.193.36]) by smtp.gmail.com with ESMTPSA id uk6sm16658814pac.27.2015.09.19.18.34.35 for (version=TLSv1/SSLv3 cipher=OTHER); Sat, 19 Sep 2015 18:35:02 -0700 (PDT) Subject: Re: [FlyRotary] Re: New psru References: Content-Type: multipart/alternative; boundary=Apple-Mail-75979570-0B9F-44A0-B9D7-0FFA47250B64 X-Mailer: iPad Mail (12H321) In-Reply-To: Message-Id: <616928C7-40E6-4191-9131-C961AD2E00C2@gmail.com> Date: Sat, 19 Sep 2015 19:34:25 -0600 To: Rotary motors in aircraft Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) --Apple-Mail-75979570-0B9F-44A0-B9D7-0FFA47250B64 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable FWIW, the spline I used on the solid coupler cost $12. =20 Tracy Sent from my iPad > On Sep 19, 2015, at 16:41, Neil Unger wrote:= >=20 > Tracy, Have hear many whispers about your =E2=80=9Cinflexible=E2=80=9D c= oupling, but just the thought makes me nervous. Most of the money on a coup= ling is in the splined block that the engine drives, the extra Flex part is n= ot a lot extra. Have al;ready has two made and destroyed both in testing bu= t the Poly and rubber (one each) survived. The poly is by far the cheapest,= but solid???? I just don=E2=80=99t feel right. Neil. > =20 > From: Tracy > Sent: Saturday, September 19, 2015 10:09 PM > To: Rotary motors in aircraft > Subject: [FlyRotary] Re: New psru > =20 > Looks like very nice work Neil, glad you picked up the ball and ran. I h= ad the same comment as Charlie but as long as you get a suitable prop the 3.= 12 will work. Only down side is I think the minimum BSFC 'sweet spot' of th= e rotary (about 5000 - 5500 rpm) may be below the usable cruise settings if p= ropped for 8500 with a fixed pitch prop. Not a big deal though. When look= ing at my flying expenses, fuel turns out to be about the cheapest item :-)= > =20 > I would urge you to investigate 'going naked' with the damper. My direct c= oupler version is at least as smooth as the rubber coupled damper version. O= nly downside is it may not be suitable for metal props but I doubt you could= find a suitable metal one for 3.12 ratio anyway. > =20 > Keep up the good work, > Tracy >=20 > Sent from my iPad >=20 >> On Sep 18, 2015, at 09:15, Charlie England w= rote: >>=20 >> I understand about debugging what you've got, before going off in a new d= irection. That's why I hated to bring it up now. :-) >>=20 >> The prop doesn't know how fast the engine is turning; it just knows how f= ast *it* is turning, and how fast it's moving through the air. I think that t= he problems start when the prop carver gets out of his comfort zone, which i= s 2700 design rpm and around 72" maximum diameter (usually less). When diame= ter goes up to 74"-76" and design rpm starts to drop, they seem to get a bit= confused. For those of us who never expect to exceed 7500 rpm, with cruise= down around 5500-6000, a 3.12 ratio would mean prop at 2400 rpm max, and ar= ound 1900 at cruise. Nothing wrong with that if we could swing a 7 foot diam= eter prop, but with small, short legged a/c, you just can't do it.=20 >>=20 >> I couldn't find anything in my old emails about the prop you had problems= with. What were its specs & mfgr? Was the 6000 rpm static, or full throttle= in flight at low altitude? Did you ever get your engine on a dyno? I know w= hat Lamar claimed for his p-port Renesis, but if those were 'corrected' dyno= numbers, they are pretty useless for real world flying at higher than sea l= evel and anything above 'standard day' temperatures (which almost never happ= ens). 250 HP seems pretty optimistic for a normally aspirated 2 rotor actual= ly flying in an a/c, but I hope you can get it working. I've been very tempt= ed to find another Renesis core & send the housings out to get them p-ported= , & if you're successful, you just might push me over the edge... >>=20 >> Charlie >>=20 >>=20 >>=20 >>> On 9/17/2015 11:17 PM, Neil Unger wrote: >>> Charlie, As usual anything is possible. The 2.85 ratio is easier to al= ter the gear set , but by the time the =E2=80=9Clittle=E2=80=9D mods are don= e the cost climbs yet again. May look at the possibility as all the drawing= s are done and alterations are now much simpler. Will get the bugs out of t= his one first. Most prop makers that I went to just do not want to hear =E2= =80=9Crotary=E2=80=9D. The revs are there but the torque is not compared to= a lyc. Much to learn in this area. Regards, neil. >>> =20 >>> From: Charlie England >>> Sent: Friday, September 18, 2015 12:44 AM >>> To: Rotary motors in aircraft >>> Subject: [FlyRotary] Re: New psru >>> =20 >>> Hi Neil, >>> =20 >>> Congrats on your progress; it looks nice. I like the idea of being able= to source some of the parts locally, given that international shipping can c= ost more than a lot of parts. >>> =20 >>> The damper issue is a real bummer. IIRC, Tracy's been running a later ve= rsion of his 2.85 directly coupled to an aluminum racing flywheel. One or tw= o others have used light weight steel flywheels, but I think they were still= using Tracy's damper mechanism, which doesn't look too complicated to build= with precision machine tools that you obviously have access to. >>> =20 >>> I know you'll hate to hear this question, but....are there provisions to= use the 2.85 ratio in your design? The reason I ask is that many of us have= no desire to turn the engine beyond 7500 rpm, and that wide ratio means cru= ise rpm at the prop of well below 2000 rpm. Most of us are flying planes tha= t can't swing the 7-8 foot diameter prop needed to maintain efficiency at th= ose low prop rpms. It also complicates getting a prop made that will perform= correctly, since it's outside the area where most prop makers have worked. I= t's confused some reputable prop makers here in the USA, even with the 2.85 r= atio. >>> =20 >>> Again, congrats on the new design, >>> =20 >>> Charlie >>> =20 >>>> On Wed, Sep 16, 2015 at 11:28 PM, Neil Unger wrote: >>>> Gents, >>>> Finally the first PSRU with a reduction of 3.12 to 1. P= ictured is the basic box which is heavily based on Tracy=E2=80=99s PSRU but w= ith the larger reduction and 2 oil lubricated thrust bearings on the prop s= haft instead of a single sealed roller bearing in Tracy=E2=80=99s. This psr= u will mount directly in place of Tracy's 2.85 reduction PSRU with no modifi= cation. >>>> Now to put to test to see if the practice matches the theory. Alre= ady found one fault. The =E2=80=9CO=E2=80=9D ring seal that seals the main b= ody of the PSRU to the base that attaches to the mounting plate is outside a= ll the attachment bolts, which means that the oil can wick down the bolts an= d make a lovely mess of your pride and joy. Now looking for more faults as t= his is easily fixed. Unlike Tracy's , this PSRU is totally sealed with O ri= ngs to ease dismantling with no clean up of whatever gasket sealer you have h= ad to use. >>>> Now the terrible part and still undecided as I am yet to cost a dam= per on the drive. Sadly it also is not cheap and may yet cost near $500 for= a =E2=80=9Dbit of rubber=E2=80=9D. Then comes a mounting plate as made by G= eoff Doddridge which he sells for around $400 USD. There is no point in me t= rying to compete with Geoff as he does a magnificent job at a cheap price. = Freight is always a horrible price so he makes the plate and there is no fr= eight from Aust to be added. >>>> The total cost in Aust dollars (including Geoff=E2=80=99s plate) wi= ll be around the $5000 which equates to $3500 USD. Then freight of possibly= $200. Currently looking at further reduction in price if you source the ge= ar set locally saving on freight both ways to Aust and back. I will have to= alter the way it is constructed so that all the mods can be done by you the= builder. Still looking! >>>> So far the progress. Neil. >>>>=20 >>>> -- >>>> Homepage: http://www.flyrotary.com/ >>>> Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/L= ist.html --Apple-Mail-75979570-0B9F-44A0-B9D7-0FFA47250B64 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
FWIW, the spline I used on the solid c= oupler cost $12.  

Tracy

Sent from my i= Pad

On Sep 19, 2015, at 16:41, Neil Unger <flyrotary@lancaironline.net> wrote:
Tracy,  Have hear many whispers about your =E2=80=9Cinflexible=E2=80= =9D =20 coupling, but just the thought makes me nervous.  Most of the money on a= =20 coupling is in the splined block that the engine drives, the extra Flex part= is=20 not a lot extra.  Have al;ready has two made and destroyed both in test= ing=20 but the Poly and rubber (one each) survived.  The poly is by far the=20= cheapest, but solid????  I just don=E2=80=99t feel right.  Neil. <= /div>
 
From: Tracy
Sent: Saturday, September 19, 2015 10:09 PM
Subject: [FlyRotary] Re: New psru
 
Looks like very nice work Neil, glad you picked up the ball and=20 ran.   I had the same comment as Charlie but as long as you get a=20= suitable prop the 3.12 will work.  Only down side is I think the minimu= m=20 BSFC 'sweet spot' of the rotary (about 5000 - 5500 rpm) may be below the usa= ble=20 cruise settings if propped for 8500 with a fixed pitch prop.  Not a big= =20 deal though.   When looking at my flying expenses, fuel turns out t= o=20 be about the cheapest item  :-)
 
I would urge you to investigate 'going naked' with the damper.  My= =20 direct coupler version is at least as smooth as the rubber coupled damper=20= version.  Only downside is it may not be suitable for metal props but I= =20 doubt you could find a suitable metal one for 3.12 ratio anyway.
 
Keep up the good work,
Tracy

Sent from my iPad

On Sep 18, 2015, at 09:15, Charlie England <flyrotary@lancaironline.net>=20 wrote:

I understand about debugging what you've go= t,=20 before going off in a new direction. That's why I hated to bring it up now= .=20 :-)

The prop doesn't know how fast the engine is turning; it just k= nows=20 how fast *it* is turning, and how fast it's moving through the air. I thin= k=20 that the problems start when the prop carver gets out of his comfort zone,= =20 which is 2700 design rpm and around 72" maximum diameter (usually less). W= hen=20 diameter goes up to 74"-76" and design rpm starts to drop, they seem to ge= t a=20 bit confused.  For those of us who never expect to exceed 7500 rpm, w= ith=20 cruise down around 5500-6000, a 3.12 ratio would mean prop at 2400 rpm max= ,=20 and around 1900 at cruise. Nothing wrong with that if we could swing a 7 f= oot=20 diameter prop, but with small, short legged a/c, you just can't do it.=20

I couldn't find anything in my old emails about the prop you had=20= problems with. What were its specs & mfgr? Was the 6000 rpm static, or= =20 full throttle in flight at low altitude? Did you ever get your engine on a= =20 dyno? I know what Lamar claimed for his p-port Renesis, but if those were=20= 'corrected' dyno numbers, they are pretty useless for real world flying at= =20 higher than sea level and anything above 'standard day' temperatures (whic= h=20 almost never happens). 250 HP seems pretty optimistic for a normally aspir= ated=20 2 rotor actually flying in an a/c, but I hope you can get it working. I've= =20 been very tempted to find another Renesis core & send the housings out= to=20 get them p-ported, & if you're successful, you just might push me over= the=20 edge...

Charlie



On 9/17/2015 11:17 PM, Neil Unger=20= wrote:
Charlie,  As usual anything is possible.  The 2.85 ratio i= s=20 easier to alter the gear set , but by the time the =E2=80=9Clittle=E2=80= =9D mods are done=20 the cost climbs yet again.  May look at the possibility as all the=20= drawings are done and alterations are now much simpler.  Will get t= he=20 bugs out of this one first.  Most prop makers that I went to just d= o=20 not want to hear =E2=80=9Crotary=E2=80=9D.  The revs are there but t= he torque is not=20 compared to a lyc.  Much to learn in this area.  Regards, = ;=20 neil.
 
Sent: Friday, September 18, 2015 12:44 AM
Subject: [FlyRotary] Re: New psru
 
Hi Neil,=20
 
Congrats on your progress; it looks nice.  I like the idea of=20= being able to source some of the parts locally, given that international= =20 shipping can cost more than a lot of parts.
 
The damper issue is a real bummer. IIRC, Tracy's been running a lat= er=20 version of his 2.85 directly coupled to an aluminum racing flywheel. One= or=20 two others have used light weight steel flywheels, but I think they were= =20 still using Tracy's damper mechanism, which doesn't look too complicated= to=20 build with precision machine tools that you obviously have access to.
 
I know you'll hate to hear this question, but....are there provisio= ns=20 to use the 2.85 ratio in your design? The reason I ask is that many of u= s=20 have no desire to turn the engine beyond 7500 rpm, and that wide ratio m= eans=20 cruise rpm at the prop of well below 2000 rpm. Most of us are flying pla= nes=20 that can't swing the 7-8 foot diameter prop needed to maintain efficienc= y at=20 those low prop rpms. It also complicates getting a prop made that will=20= perform correctly, since it's outside the area where most prop makers ha= ve=20 worked. It's confused some reputable prop makers here in the USA, even w= ith=20 the 2.85 ratio.
 
Again, congrats on the new design,
 
Charlie
 
On Wed, Sep 16, 2015 at 11:28 PM, Neil Unger <= span dir=3D"ltr"><flyrotary@lancaironline.net>=20 wrote:
Gents,
           = ;  =20 Finally the first PSRU with a reduction of 3.12  to 1.  Pict= ured=20 is the basic box which is heavily based on Tracy=E2=80=99s PSRU but wi= th the=20 larger reduction and 2 oil lubricated thrust   bearings on t= he=20 prop shaft instead of a single sealed roller bearing in Tracy=E2=80=99= s. =20 This psru will mount directly in place of Tracy's 2.85 reduction PSRU w= ith=20 no modification.
    Now to put to test to see if the practice matc= hes=20 the theory.  Already found one fault. The =E2=80=9CO=E2=80=9D rin= g seal that seals=20 the main body of the PSRU to the base that attaches to the mounting pl= ate=20 is outside all the attachment bolts, which means that the oil can wick= =20 down the bolts and make a lovely mess of your pride and joy.  Now= =20 looking for more faults as this is easily fixed.  Unlike Tracy's ,= =20 this PSRU is totally sealed with O rings to ease dismantling with no c= lean=20 up of whatever gasket sealer you have had to use.
    Now the terrible part and still undecided as I= am=20 yet to cost a damper on the drive.  Sadly it also is not cheap an= d=20 may yet cost near $500 for a =E2=80=9Dbit of rubber=E2=80=9D.  Th= en comes a mounting=20 plate as made by Geoff Doddridge which he sells for around $400 USD.&n= bsp;=20 There is no point in me trying to compete with Geoff as he does a=20 magnificent job at a cheap price.  Freight is always a horrible p= rice=20 so he makes the plate and there is  no freight from Aust to be=20= added.
    The total cost in Aust dollars (including Geof= f=E2=80=99s=20 plate) will be around the $5000 which equates to $3500 USD.  Then= =20 freight of possibly $200.  Currently looking at further reduction= in=20 price if you source the gear set locally saving on freight both ways t= o=20 Aust and back.  I will have to alter the way it is constructed so= =20 that all the mods can be done by you the builder.  Still=20 looking!
    So far the progress. =20 Neil.

--
Homepage:  http://www.flyrotary.com/
Archive and=20 UnSub:   http://mail.lancaironline.net:81/lists/flyrotary/List.html

=
 

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