Return-Path: Received: from mailout2.pacific.net.au ([61.8.0.85] verified) by logan.com (CommuniGate Pro SMTP 4.2.8) with ESMTP id 605631 for flyrotary@lancaironline.net; Thu, 13 Jan 2005 03:11:14 -0500 Received-SPF: none receiver=logan.com; client-ip=61.8.0.85; envelope-from=peon@pacific.net.au Received: from mailproxy1.pacific.net.au (mailproxy1.pacific.net.au [61.8.0.86]) by mailout2.pacific.net.au (8.12.3/8.12.3/Debian-7.1) with ESMTP id j0D8AgHn029356 for ; Thu, 13 Jan 2005 19:10:42 +1100 Received: from ar1 (ppp262B.dyn.pacific.net.au [61.8.38.43]) by mailproxy1.pacific.net.au (8.12.3/8.12.3/Debian-7.1) with SMTP id j0D8Adj8000681 for ; Thu, 13 Jan 2005 19:10:40 +1100 Message-ID: <000e01c4f947$29064ed0$2b26083d@ar1> From: "Leon" To: "Rotary motors in aircraft" References: Subject: For Ken Welter was Re: [FlyRotary] Re: Rotating Assy Stuff Date: Thu, 13 Jan 2005 19:09:08 +1100 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000B_01C4F9A3.5B700530" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 This is a multi-part message in MIME format. ------=_NextPart_000_000B_01C4F9A3.5B700530 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: [FlyRotary] Rotating Assy Stuff was Re: [FlyRotary] dyHowdy Ken, Yes, we have a mandrel for the rotors themselves, and mandrels for the = lightened, as well as stock manual flywheels. This is used when = swapping a manual flywheel for an auto counterweight and a lightened = flywheel. Of course, my Balancier does a wide variety of piston engines as well = and he has literally a wall full of different mandrels to hold various = flywheels etc from piston engine cars as well as rotaries. So the procedure is to find the lightest rotor, and then dynamically = balance that on the rotor mandrel. Obviously, the balancing procedure = of removing metal from the rotor lightens it even more. The second (and = 3rd if a 20B) are then dynamically balanced out until they weigh the = same as the first rotor. =20 As you saw from one of the pix I posted, I had 2 12A rotors that were = EXACTLY the same weight. You will note the ball bearings held with = "Blue Tack" to make allowance for the oil. With the later model shafts, = we normally just put a carefully calibrated brass weight into the rotor = lobe hole(s), and then adjust where necessary with ball bearings and = "Blue Tack".=20 The extra weight is to allow for the mass of oil that has been = determined by trial and error over the years. It does vary a bit from = rotor model to rotor model as the internal volume of the earlier rotors = are less than the later models due to the thinner wall castings. = Obviously 10A and 12A rotors have smaller internal capacity than any of = the 13B rotors. So it's a bit of a "Black Art". The rotors are then put on the shaft and the whole assy is then spun up = and the counterweights are adjusted until the whole assy balances out = nicely. Using the rotors themselves is easier than fiddling with a = collar and removable masses like they do on V8s etc. Has to be done on = a piston engine crank, but using the rotors themselves workds just = dandy on rotaries. Cheers, Leon ----- Original Message -----=20 From: Ken Welter=20 To: Rotary motors in aircraft=20 Sent: Thursday, January 13, 2005 4:45 AM Subject: [FlyRotary] Re: Rotating Assy Stuff was Re: [FlyRotary] = dynamic balancing Hey Leon You talk about mandrels, are the mandrels for balancing the rotors = first?? I assume that you balance the rotors first and then put the on the = e-shaft and balance the assembly. Ken ------=_NextPart_000_000B_01C4F9A3.5B700530 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: [FlyRotary] Rotating Assy Stuff was Re: = [FlyRotary] dy
Howdy Ken,
 
Yes,  we have a mandrel for the = rotors=20 themselves, and mandrels for the lightened,  as well as stock=20 manual flywheels.  This is used when swapping a manual = flywheel for an=20 auto counterweight and a lightened flywheel.
 
Of course,  my Balancier does a = wide variety=20 of piston engines as well and he has literally a wall full of different = mandrels=20 to hold various flywheels etc from piston engine cars as well as=20 rotaries.
 
So the procedure is to find the = lightest=20 rotor,  and then dynamically balance that on the rotor = mandrel. =20 Obviously,  the balancing procedure of removing metal from the = rotor=20 lightens it even more.  The second (and 3rd if a 20B) are then = dynamically=20 balanced out until they weigh the same as the first rotor.  =20
 
As you saw from one of the pix I = posted,  I=20 had 2 12A rotors that were EXACTLY the same weight.  You will note = the ball=20 bearings held with "Blue Tack" to make allowance for the oil.  With = the=20 later model shafts,  we normally just put a carefully calibrated = brass=20 weight into the rotor lobe hole(s),  and then adjust = where necessary=20 with ball bearings and "Blue Tack". 
 
The extra weight is to allow for = the mass of=20 oil that has been determined by trial and error over the years.  It = does=20 vary a bit from rotor model to rotor model as the internal volume of the = earlier=20 rotors are less than the later models due to the thinner wall = castings. =20 Obviously 10A and 12A rotors have smaller internal capacity than any of = the 13B=20 rotors.  So it's a bit of a "Black Art".
 
The rotors are then put on the = shaft and the=20 whole assy is then spun up and the counterweights are adjusted until the = whole=20 assy balances out nicely.  Using the rotors themselves is easier = than=20 fiddling with a collar and removable masses like they do on V8s = etc.  Has=20 to be done on a piston engine crank,  but using the rotors = themselves=20 workds just dandy on rotaries.
 
Cheers,
 
Leon
----- Original Message -----
From:=20 Ken=20 Welter
Sent: Thursday, January 13, = 2005 4:45=20 AM
Subject: [FlyRotary] Re: = Rotating Assy=20 Stuff was Re: [FlyRotary] dynamic balancing

   Hey Leon
  You talk about mandrels, are the = mandrels for=20 balancing the rotors first??
  I assume that you balance the rotors = first and=20 then put the on the e-shaft and balance the assembly.
  Ken



------=_NextPart_000_000B_01C4F9A3.5B700530--