X-Virus-Scanned: clean according to Sophos on Logan.com From: "Neil Unger" Received: from nskntmtas05p.mx.bigpond.com ([61.9.168.149] verified) by logan.com (CommuniGate Pro SMTP 6.1.5) with ESMTPS id 8000360 for flyrotary@lancaironline.net; Fri, 18 Sep 2015 18:20:05 -0400 Received-SPF: pass receiver=logan.com; client-ip=61.9.168.149; envelope-from=neil.unger@bigpond.com Received: from nskntcmgw05p ([61.9.169.165]) by nskntmtas05p.mx.bigpond.com with ESMTP id <20150918221929.CZVN25105.nskntmtas05p.mx.bigpond.com@nskntcmgw05p> for ; Fri, 18 Sep 2015 22:19:29 +0000 Received: from UserPC ([124.176.102.27]) by nskntcmgw05p with BigPond Outbound id JmKN1r00A0bUJXQ01mKNRk; Fri, 18 Sep 2015 22:19:29 +0000 X-Authority-Analysis: v=2.0 cv=IpacgcDg c=1 sm=1 a=bDaJfmkAzPY7btnRrgA5VA==:17 a=1IlZJK9HAAAA:8 a=Ia-xEzejAAAA:8 a=7g1VtSJxAAAA:8 a=hvVOCU7xfEwk5I2NJBQA:9 a=QEXdDO2ut3YA:10 a=Qa1je4BO31QA:10 a=ItJo5-BE8QqYyJXO:21 a=fXGJTRSTuVQvJNg-:21 a=4PR2P7QzAAAA:8 a=tU4VTa4lERrP5470CbkA:9 a=_W_S_7VecoQA:10 a=bDaJfmkAzPY7btnRrgA5VA==:117 Message-ID: <14CDCF0D744540768EB3A4B802696751@UserPC> To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: New psru Date: Sat, 19 Sep 2015 08:19:06 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_006B_01D0F2B3.DA46B880" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 15.4.3555.308 X-MimeOLE: Produced By Microsoft MimeOLE V15.4.3555.308 This is a multi-part message in MIME format. ------=_NextPart_000_006B_01D0F2B3.DA46B880 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Charlie, The 250 hp prop was a Prince P tip 70 inch dia with a 90 inch = pitch. My renesis P port is supposed to produce the 250 HP. To be = honest, Bull droppings!! I then bought a whirlwind ground adjustable = expecting a huge improvement. Nope, did not happen, in fact I think it = was worse. That prop has a max HP of 200 and with the setting at the = usual man. specs ( I cannot recall) I did get close to 7500 rpm, so = with calculations on the back of an envelope, it would appear that the P = ported renesis is developing somewhere around the 210 HP max. at 1000 = feet above sea level. Now in hindsight I believe that the Prince prop = is equal to better (marginally) than the Ground adjustable and = significantly cheaper. =20 My aim of 8000 rpm is solely for take off HP, and then will be = extremely happy with 5500 to 6000 for cruise, or less. No never did get = the engine onto a dyno due to difficulties in attaching quickly, so what = hp I have is it, and basically guess work. Still working on a second = engine to replace the existing one. I have improved the cooling drag = second time around, and narrowed the frontal area quite a lot. Part of = this was to get Jeff Doddridge to alter his mounting plate to make the = mounts equidistant from the prop centreline. The only other alteration = I think should be done is to move the starter over to the RH side of the = motor to get it away from that hot exhaust. It never ends. Neil.=20 From: Charlie England=20 Sent: Saturday, September 19, 2015 1:15 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: New psru I understand about debugging what you've got, before going off in a new = direction. That's why I hated to bring it up now. :-) The prop doesn't know how fast the engine is turning; it just knows how = fast *it* is turning, and how fast it's moving through the air. I think = that the problems start when the prop carver gets out of his comfort = zone, which is 2700 design rpm and around 72" maximum diameter (usually = less). When diameter 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 around 1900 at cruise. Nothing wrong with = that if we could swing a 7 foot 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 = 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 what 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 level and anything above 'standard day' = temperatures (which almost never happens). 250 HP seems pretty = optimistic for a normally aspirated 2 rotor actually flying in an a/c, = but I hope you can get it working. I've been very tempted 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... Charlie On 9/17/2015 11:17 PM, Neil Unger wrote: Charlie, As usual anything is possible. The 2.85 ratio is easier to = alter the gear set , but by the time the =E2=80=9Clittle=E2=80=9D mods = are done the cost climbs yet again. May look at the possibility as all = the drawings are done and alterations are now much simpler. Will get = the bugs out of this 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. From: Charlie England=20 Sent: Friday, September 18, 2015 12:44 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: New psru 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 cost more than a lot of parts.=20 The damper issue is a real bummer. IIRC, Tracy's been running a later = version of his 2.85 directly coupled to an aluminum racing flywheel. One = or two 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. 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 cruise rpm at the prop of well below 2000 rpm. Most of us = are flying planes that can't swing the 7-8 foot diameter prop needed to = maintain efficiency at those 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. It's confused some reputable prop = makers here in the USA, even with the 2.85 ratio.=20 Again, congrats on the new design, Charlie 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. = Pictured is the basic box which is heavily based on Tracy=E2=80=99s = PSRU but with the larger reduction and 2 oil lubricated thrust = bearings on the prop shaft instead of a single sealed roller bearing in = Tracy=E2=80=99s. This psru will mount directly in place of Tracy's 2.85 = reduction PSRU with no modification. Now to put to test to see if the practice matches the theory. = Already found one fault. The =E2=80=9CO=E2=80=9D ring seal that seals = the main body of the PSRU to the base that attaches to the mounting = plate is outside all the attachment bolts, which means that the oil can = wick down the bolts and make a lovely mess of your pride and joy. Now = looking for more faults as this is easily fixed. Unlike Tracy's , this = PSRU is totally sealed with O rings to ease dismantling with no clean up = of whatever gasket sealer you have had to use. Now the terrible part and still undecided as I am yet to cost a = damper 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 Geoff Doddridge which he sells for around $400 USD. There is = no point in me trying 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 freight from Aust to be added. The total cost in Aust dollars (including Geoff=E2=80=99s plate) = will 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 gear 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. -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_006B_01D0F2B3.DA46B880 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Charlie,   The 250 hp prop was a Prince P tip 70 inch dia = with a=20 90 inch pitch.  My renesis P port is supposed to produce the 250 = HP. =20 To be honest, Bull droppings!!  I then bought a whirlwind ground = adjustable=20 expecting a huge improvement.  Nope, did not happen, in fact I = think it was=20 worse.  That prop has a max HP of 200 and with the setting at the = usual=20 man. specs ( I cannot recall) I did get close to 7500 rpm,  so with = calculations on the back of an envelope, it would appear that the P = ported=20 renesis is developing somewhere around the 210 HP max.  at 1000 = feet above=20 sea level.  Now in hindsight I believe that the Prince prop is = equal to=20 better (marginally) than the Ground adjustable and significantly = cheaper. =20
    My aim of 8000 rpm is solely for take off HP, = and then=20 will be extremely happy with 5500 to 6000 for cruise, or less.  No = never=20 did get the engine onto a dyno due to difficulties in attaching quickly, = so what=20 hp I have is it, and basically guess work.  Still working on a = second=20 engine to replace the existing one.  I have improved the cooling = drag=20 second time around, and narrowed the frontal area quite a lot.  = Part of=20 this was to get Jeff Doddridge  to alter his mounting plate to make = the=20 mounts equidistant from the prop centreline.  The only other = alteration I=20 think should be done is to move the starter over to the RH side of the = motor to=20 get it away from that hot exhaust.  It never ends.  Neil. =
 
Sent: Saturday, September 19, 2015 1:15 AM
Subject: [FlyRotary] Re: New psru
 
I understand about debugging what you've = got, before=20 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 = knows=20 how fast *it* is turning, and how fast it's moving through the air. I = think that=20 the problems start when the prop carver gets out of his comfort zone, = which is=20 2700 design rpm and around 72" maximum diameter (usually less). When = diameter=20 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=20 down around 5500-6000, a 3.12 ratio would mean prop at 2400 rpm max, and = around=20 1900 at cruise. Nothing wrong with that if we could swing a 7 foot = diameter=20 prop, but with small, short legged a/c, you just can't do it.

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

Charlie



On = 9/17/2015 11:17 PM, Neil Unger wrote:
Charlie,  As usual anything is possible.  The 2.85 = ratio is=20 easier to alter the gear set , but by the time the = =E2=80=9Clittle=E2=80=9D mods are done the=20 cost climbs yet again.  May look at the possibility as all the = drawings=20 are done and alterations are now much simpler.  Will get the bugs = out of=20 this one first.  Most prop makers that I went to just do not want = to hear=20 =E2=80=9Crotary=E2=80=9D.  The revs are there but the torque is = not compared to a=20 lyc.  Much to learn in this area.  Regards,  = neil.
 
From: Charlie England
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 being=20 able to source some of the parts locally, given that international = shipping=20 can cost more than a lot of parts.
 
The damper issue is a real bummer. IIRC, Tracy's been running a = later=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 still=20 using Tracy's damper mechanism, which doesn't look too complicated to = build=20 with precision machine tools that you obviously have access to.
 
I know you'll hate to hear this question, but....are there = provisions to=20 use the 2.85 ratio in your design? The reason I ask is that many of us = have no=20 desire to turn the engine beyond 7500 rpm, and that wide ratio means = cruise=20 rpm at the prop of well below 2000 rpm. Most of us are flying planes = that=20 can't swing the 7-8 foot diameter prop needed to maintain efficiency = at those=20 low prop rpms. It also complicates getting a prop made that will = perform=20 correctly, since it's outside the area where most prop makers have = worked.=20 It's confused some reputable prop makers here in the USA, even with = the 2.85=20 ratio.
 
Again, congrats on the new design,
 
Charlie
 
On Wed, Sep 16, 2015 at 11:28 PM, Neil Unger = <flyrotary@lancaironline.net>=20 wrote:
Gents,
=
           &n= bsp; =20 Finally the first PSRU with a reduction of 3.12  to 1.  = Pictured=20 is the basic box which is heavily based on Tracy=E2=80=99s PSRU but = with the larger=20 reduction and 2 oil lubricated thrust   bearings on the = prop shaft=20 instead of a single sealed roller bearing in Tracy=E2=80=99s.  = This psru will=20 mount directly in place of Tracy's 2.85 reduction PSRU with no=20 modification.
    Now to put to test to see if the practice = matches=20 the theory.  Already found one fault. The =E2=80=9CO=E2=80=9D = ring seal that seals the=20 main body of the PSRU to the base that attaches to the mounting = plate is=20 outside all the attachment bolts, which means that the oil can wick = down the=20 bolts and make a lovely mess of your pride and joy.  Now = looking for=20 more faults as this is easily fixed.  Unlike Tracy's , this = PSRU is=20 totally sealed with O rings to ease dismantling with no clean up of = whatever=20 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 = and may=20 yet cost near $500 for a =E2=80=9Dbit of rubber=E2=80=9D.  Then = comes a mounting plate=20 as made by Geoff Doddridge which he sells for around $400 USD.  = There=20 is no point in me trying to compete with Geoff as he does a = magnificent job=20 at a cheap price.  Freight is always a horrible price so he = makes the=20 plate and there is  no freight from Aust to be added.
    The total cost in Aust dollars (including = Geoff=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 = to Aust=20 and back.  I will have to alter the way it is constructed so = that all=20 the mods can be done by you the builder.  Still 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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