X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imf19aec.mail.bellsouth.net ([205.152.59.67] verified) by logan.com (CommuniGate Pro SMTP 5.0.4) with ESMTP id 891918 for flyrotary@lancaironline.net; Wed, 21 Dec 2005 19:08:44 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.67; envelope-from=atlasyts@bellsouth.net Received: from ibm59aec.bellsouth.net ([65.2.250.50]) by imf19aec.mail.bellsouth.net with ESMTP id <20051222000800.EHAP23296.imf19aec.mail.bellsouth.net@ibm59aec.bellsouth.net> for ; Wed, 21 Dec 2005 19:08:00 -0500 Received: from [192.168.0.100] (really [65.2.250.50]) by ibm59aec.bellsouth.net with ESMTP id <20051222000758.OSV11189.ibm59aec.bellsouth.net@[192.168.0.100]> for ; Wed, 21 Dec 2005 19:07:58 -0500 Mime-Version: 1.0 (Apple Message framework v746.2) In-Reply-To: References: Content-Type: multipart/alternative; boundary=Apple-Mail-2-136589201 Message-Id: <0C11B7EF-05A7-47A5-B3A4-D621E9AD18E4@bellsouth.net> From: Bulent Aliev Subject: Re: [FlyRotary] Re: Props Date: Wed, 21 Dec 2005 19:08:15 -0500 To: "Rotary motors in aircraft" X-Mailer: Apple Mail (2.746.2) --Apple-Mail-2-136589201 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Don't ask me George. I'm not an engineer or good with mathematics. Ed A will know better. Buly On Dec 21, 2005, at 6:20 PM, george lendich wrote: > Thanks Buly, > So, Pitch" = MPH x12 x 5280 > RPM x 60 > I figure 12 (inches in a foot) and 5280 ( feet in a mile) and 60 > ( minute in an hour). > So the top line is converted into inches per minute and the bottom > line RPM. > > So, Pitch " = inches per minute > RPM > > Does that look right to you ? > George ( down under) > > > 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= > > > Bulent "Buly" Aliev http://home.bellsouth.net/p/s/community.dll? ep=16&ext=1&groupid=164323&ck= --Apple-Mail-2-136589201 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=ISO-8859-1 Don't ask me George. I'm not an = engineer or good with mathematics. Ed A will know = better.
Buly
On Dec 21, 2005, at 6:20 PM, george = lendich wrote:

Thanks = Buly,
So, Pitch"=A0 =3D MPH x12 x = 5280
=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 =A0RPM x = 60
I figure 12 (inches in a foot) and 5280 ( feet in a mile) and = 60 (=A0minute in an hour).
So the top line is converted into inches per minute = and the bottom line RPM.
=A0
So, Pitch " =3D inches per = minute
=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 = RPM
=A0
Does that look=A0right to you ?
George ( down = under)
=A0
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:

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,


Thanks = Perry. This makes me feel much better. Looks like the = formulas
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



--
Homepage:=A0 http://www.flyrotary.comArchive and = UnSub: =A0 =










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