X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 10 [X] Return-Path: Received: from an-out-0708.google.com ([209.85.132.243] verified) by logan.com (CommuniGate Pro SMTP 5.1.8) with ESMTP id 1986547 for flyrotary@lancaironline.net; Sun, 15 Apr 2007 12:03:46 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.132.243; envelope-from=rotary.thjakits@gmail.com Received: by an-out-0708.google.com with SMTP id c34so1375306anc for ; Sun, 15 Apr 2007 09:02:59 -0700 (PDT) DKIM-Signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=nQ9wi5vECsm/CC9/yxyULzCkBIHjCkcx0X+zh9Dy89iqr3P7pFquac/a/zKcJXwPrf2tIhzhIyyiRCD8uF9JcHHH3bxUTuB77aDmcG9HSCeVDvWAeUmuW+Fa/zxNOks0KKtwD6M0s1osZCWOghwNi/A/oYYJWK8zfxCh7BM554I= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=ktlwCuHo3j0VvgzhC1O4GAS5SVxGWl1bYV8iWQZM198QrDt9nssSxPbwefn5rHG7Hijld6eYE5AVJE1z3acGaLpckCFt8ujRh2SgDwMPYPTwH9mjUttN8MKSXf1F+wKEsrG4b/D8JMECy2+XcJXFuhIa6GMtAbpGJRph7V22hhE= Received: by 10.100.33.14 with SMTP id g14mr3861671ang.1176652978756; Sun, 15 Apr 2007 09:02:58 -0700 (PDT) Received: by 10.100.197.4 with HTTP; Sun, 15 Apr 2007 09:02:58 -0700 (PDT) Message-ID: <63163d560704150902u741ee7e2y9a5524b632c95371@mail.gmail.com> Date: Sun, 15 Apr 2007 11:02:58 -0500 From: "Thomas Jakits" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: single rotor testing In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_32420_316605.1176652978673" References: ------=_Part_32420_316605.1176652978673 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline Rusty, you should get a speeding ticket!! Everyone else is toiling away for years and you just slam together some parts and start it! Sounds like a record! BUT, there is always a "but" isn't there? :)) Of course you a right about the small 2-rotor. I still ask myself why never any of these companies went to a pressure oil-system to avoid the needle bearings, limiting rpm??? Whether it is oil, water or air-cooled should not matter that much if the cooling is adequate. Looking at the rotors of the small engines, it does not seem necessary to change a lot in the rotor, just change the needle-race for a solid bearing. A new e-shaft with oil-system should be a lot easier than a new rotor.... It seems these companies all get stuck at around 9-10K rpm, hell a Mazda can and does do more. For your 1-rotor, you a right about more inertia from the flywheel, but you could keep mass down by making it a big diameter with most of the mass at the rim, inertia-effect goes up with radius at the same weight (actually it goes up with the square, if don't get it completely wrong here) Also what about a freewheel-unit, before the PSRU? Something like in car-auto-trans, it would not eliminate the torque reversal in the engine, but keep it from going into the gearbox/prop. So you get only a on-off-on situation which is better than forward-back-forward.... Also, it seems worth a math exercise for expenses (for the specialists on here) to see what the parts would cost for a 2-rotor pressure -oiled small engine. Parts from any of the presently selling companies... http://www.nova-racing.com/nova_gb/Preise/bild15.htm (on this one you can see some oil-hole?? on the e-shaft, it may be possible to open this up for a pressure-oil system) http://www.nova-racing.com/nova_gb/Preise/bild16.htm http://www.nova-racing.com/nova_gb/Preise/bild14.htm http://www.nova-racing.com/nova_gb/Preise/bild13.htm prices seem not too bad - http://www.nova-racing.com/nova_gb/index.htm (Note- this is in Euro, but it includes nearly 20% tax, which one might get back) I see, that one cannot really scale horsepower and $. At some point machining and production will cost something no matter what.... By the time the Mazda-1-rotor is smooth and idles well, it probably will cost the same as a small re-engineered 2- or 3-rotor. You mentioned Alu-side housings - as the price is now, these already buy a whole 40-hp engine..... unless Mazda goes Alu at some point.... Nevertheless, keep hacking on it!! Best Regards, Thomas Jakits ..snipped > What we really need is custom made 2 rotor engines in a smaller size. > It's certainly been done before, but so far, no one has had any long term > success at selling aircraft engines. You'd hope there would be a big push > on these now, since the LSA planes are a hot topic, but I just don't see > it. Rotatmax is talking a good game, but they aren't really ready to prove > it yet. > > Cheers, > Rusty > > PS- There's a 3/8" x 1/8" x 1/16" piece of aluminum missing from the > inside of the intake. I'll look in the exhaust to see if I can see any > evidence of it's journey through the rotor housing :-( > > Ouuuuch!! > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > > > ------=_Part_32420_316605.1176652978673 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline
Rusty,
 
you should get a speeding ticket!!
Everyone else is toiling away for years and you just slam together some parts and start it!
Sounds like a record!
 
BUT, there is always a "but" isn't there? :))
 
Of course you a right about the small 2-rotor.
I still ask myself why never any of these companies went to a pressure oil-system to avoid the needle bearings, limiting rpm??? Whether it is oil, water or air-cooled should not matter that much if the cooling is adequate. Looking at the rotors of the small engines, it does not seem necessary to change a lot in the rotor, just change the needle-race for a solid bearing.
A new e-shaft with oil-system should be a lot easier than a new rotor....
It seems these companies all get stuck at around 9-10K rpm, hell a Mazda can and does do more.
 
For your 1-rotor, you a right about more inertia from the flywheel, but you could keep mass down by making it a big diameter with most of the mass at the rim, inertia-effect goes up with radius at the same weight (actually it goes up with the square, if don't get it completely wrong here)
Also what about a freewheel-unit, before the PSRU? Something like in car-auto-trans, it would not eliminate the torque reversal in the engine, but keep it from going into the gearbox/prop.
So you get only a on-off-on situation which is better than forward-back-forward....
 
Also, it seems worth a math exercise for expenses (for the specialists on here) to see what the parts would cost for a 2-rotor pressure -oiled small engine.
Parts from any of the presently selling companies...
 
http://www.nova-racing.com/nova_gb/Preise/bild15.htm (on this one you can see some oil-hole?? on the e-shaft, it may be possible to open this up for a pressure-oil system)
 
 
(Note- this is in Euro, but it includes nearly 20% tax, which one might get back)
I see, that one cannot really scale horsepower and $. At some point machining and production will cost something no matter what.... 
 
By the time the Mazda-1-rotor is smooth and idles well, it probably will cost the same as a small re-engineered 2- or 3-rotor. You mentioned Alu-side housings - as the price is now, these already buy a whole 40-hp engine..... unless Mazda goes Alu at some point....
 
Nevertheless, keep hacking on it!!
 
Best Regards,
 
Thomas Jakits
 
 
..snipped
 
What we really need is custom made 2 rotor engines in a smaller size.  It's certainly been done before, but so far, no one has had any long term success at selling aircraft engines.  You'd hope there would be a big push on these now, since the LSA planes are a hot topic, but I just don't see it.  Rotatmax is talking a good game, but they aren't really ready to prove it yet.  
 
Cheers,
Rusty 
 
PS- There's a 3/8" x 1/8" x 1/16" piece of aluminum missing from the inside of the intake.  I'll look in the exhaust to see if I can see any evidence of it's journey through the rotor housing :-( 
 
 Ouuuuch!!    
 

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



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