X-Mozilla-Keys:                                                                                 

Forwarded Message:

To: Perry Mick
From: Jeff Spitzer 
Subject: Re: direct drive
Date: Wed, 03 Nov 1999 08:22:08 -0800
-----
I haven't had a chance to look at your CAD file.  If it's not too
difficult, I'd pull off the flywheel and have a look at the taper.  Here's
why:  The taper is transmitting all its loads through the clamping
friction.  Typically, the loads are principally torque only.  You have
added a significant load perpendicular to the torque (bending) that will
also need to be resisted by the same friction.  If the vector sum of the
loads exceeds the static friction, it's gonna slip. This is based on a
guess that the friction bending resistance is stiffer than the bending
resistance offered by the radial contact over the length of the taper.  My
gut says that would be the case.  In other words, the joint would slip
slightly before the "tube within a tube" would resist the bending.  I
really think this might be a problem for you but don't have the time to
analyze it further.

Jeff Spitzer

I hope Jeff doesn't mind me forwarding this message.  I've had a private
conversation with him on the matter on the side, and his input here may
also be valid.

About the runout on the prop extension, I'll have to measure it.

Also check the flywheel for cracks where the prop extension
is bolted to it.

Paul Lamar
 
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