X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imf24aec.mail.bellsouth.net ([205.152.59.72] verified) by logan.com (CommuniGate Pro SMTP 5.0.4) with ESMTP id 891727 for flyrotary@lancaironline.net; Wed, 21 Dec 2005 17:15:06 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.72; envelope-from=atlasyts@bellsouth.net Received: from ibm68aec.bellsouth.net ([65.2.250.50]) by imf24aec.mail.bellsouth.net with ESMTP id <20051221221419.LNSJ25886.imf24aec.mail.bellsouth.net@ibm68aec.bellsouth.net> for ; Wed, 21 Dec 2005 17:14:19 -0500 Received: from [192.168.0.100] (really [65.2.250.50]) by ibm68aec.bellsouth.net with ESMTP id <20051221221417.JYUG8737.ibm68aec.bellsouth.net@[192.168.0.100]> for ; Wed, 21 Dec 2005 17:14:17 -0500 Mime-Version: 1.0 (Apple Message framework v746.2) In-Reply-To: References: Content-Type: multipart/alternative; boundary=Apple-Mail-1-129769379 Message-Id: <7C43A126-F9C2-4455-99A3-AB3DD3854C26@bellsouth.net> From: Bulent Aliev Subject: Re: [FlyRotary] Re: Props Date: Wed, 21 Dec 2005 17:14:35 -0500 To: "Rotary motors in aircraft" X-Mailer: Apple Mail (2.746.2) --Apple-Mail-1-129769379 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Thanks George. my mistake was that i did not convert it to MPH. I was also given the formula for cruise speed: Pitch" x RPM x 60 = MPH 12 x 5280 Buly On Dec 21, 2005, at 4:39 PM, george lendich wrote: > Buly, > Looking at the formula given by members on this list, 2 out of 3 > were spot > on with Hoverhawk and the third was close. > > Examples: > 1. Prop Dia x 3.1416x RPM/ 720 - Correct! > > 2. Prop RPM x Dia x .00436 - Correct ( 3.14/ 720 =.00436) > > 3. 3.14 x 64 {given prop dia} ( 5500/2.17 {given RPM})= 508346/707 - > slightly incorrect ( as compared to the other 3 examples, which > include > Hoverhawk) > > i.e 3.14/ 707 = .004809 whereas all the others are 3.14/ 720 = .00436. > > Now that I have that sorted - can someone tell me how to calculate > pitch, > easily!! > George ( down under) > > >> Thanks Perry. This makes me feel much better. Looks like the formulas >> given to me were not good. >> Buly >> On Dec 19, 2005, at 2:00 PM, Perry Casson wrote: >> >>> I think your math is off a bit - Here's a online calculator http:// >>> www.hoverhawk.com/propspd.html >>> >>> I think 6900 puts a 72" prop close to mach 0.9 but I've never ran >>> mine above 6500 >>> >>> Perry Casson >>> >>> >>> >>> -- >>> Homepage: http://www.flyrotary.com/ >>> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ >> >> Buly >> atlasyts@bellsouth.net >> >> >> >> >> -- >> Homepage: http://www.flyrotary.com/ >> Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ >> > > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ Bulent "Buly" Aliev http://home.bellsouth.net/p/s/community.dll? ep=16&ext=1&groupid=164323&ck= --Apple-Mail-1-129769379 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=ISO-8859-1 Thanks George. my mistake was = that i did not convert it to MPH.
I was also given the formula for = cruise speed:

Pitch" = x RPM x 60=A0=A0=3D MPH
=A0=A0 =A0=A0 =A012 x = 5280

Buly
On = Dec 21, 2005, at 4:39 PM, george lendich wrote:

Buly,
Looking at = the formula given by members on this list, 2 out of 3 were = spot
on with Hoverhawk and the third = was close.

Examples:
1. Prop Dia x = 3.1416x RPM/ 720 - Correct!

2. Prop RPM x Dia x .00436 - = Correct ( 3.14/ 720 =3D.00436)

3. 3.14 x 64 {given prop dia} ( = 5500/2.17 {given RPM})=3D 508346/707 -
slightly = incorrect ( as compared to the other 3 examples, which include
Hoverhawk)

i.e 3.14/ 707 =3D .004809 = whereas all the others are 3.14/ 720 =3D .00436.

Now that = I have that sorted - can someone tell me how to calculate = pitch,
easily!!
George ( down under)


Thanks = Perry. This makes me feel much better. Looks like the formulas
given to me were not good.
Buly
On Dec 19, = 2005, at 2:00 PM, Perry Casson wrote:

I think your math is off a bit - Here's a online = calculator http://

I think 6900 puts a 72" prop = close to=A0 mach 0.9 but = I've never ran
mine above 6500

Perry = Casson



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Homepage:=A0 = http://www.flyrotary.com/





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