Guys,
The calculations on hoverhawk will will give you the tip speed with the
aircraft tied down to the ground. Tip speed in flight is influenced greatly
by TAS. Attached is a spread sheet to allow you to calculate your top mach
numbers based on engine rpm, gear ratio, prop diameter, and TAS.
This will give you a better idea what your tip is doing at what airspeed.
Larry


-----Original Message-----
From: Rotary Engine [mailto:rotaryeng@earthlink.net]
Sent: Thursday, July 12, 2007 6:24 PM
To: AARotary Engine
Subject: Prop diameter, pitch, rpm??????

I did look briefly on the internet but did not find clarity.  Perhaps
I should look harder....anyway, here is the problem:  Some of the LSA
engine prop combinations use quite short props, much shorter than I
am used to.    Could some one tell me the tip speed of a sixty inch
diameter prop turning   3400 rpm.

> Jerry


Go to www.warpdrive.com (not actually the prop company, but a major
distributor).  They have a link to an online prop speed/rpm/diameter
calculator.

Keith

The link doesn't work for me..  any one else?

-dave

My error, it's www.warpdriveprops.com, but the actual tip speed
calculator is at http://www.hoverhawk.com/propspd.html

Keith

Guys,
The calculations on hoverhawk will will give you the tip speed with the
aircraft tied down to the ground. Tip speed in flight is influenced greatly
by TAS. Attached is a spread sheet to allow you to calculate your top mach
numbers based on engine rpm, gear ratio, prop diameter, and TAS.
This will give you a better idea what your tip is doing at what airspeed.
Larry

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