If you still want to use the third Barry rubber bushing as a front mount
this might work.
Decouple the front mount beam from the rest of the structure using rod ends
or rubber bushings. As Vance is fond of quoting some English engineer: "an
ounce of rubber is worth a pound of engineering." :) Sometimes you can add
too many tubes to a space frame and wind up with undesirable side effects
such as local bending moments in joints that lead to cracks.
Again 1/4 scale balsa stick models made from 3/16th square do wonders when
it comes to understanding a particular space frame design and I highly recommend
doing one.
Paul Lamar
I don't think I received your original email on this, and you didn't
include my corrected drawing in my original email. Here is my corrected
drawing again, see if there are any errors. I added the three tubes you
had redlined in.
Perry
Needs yet more tubes.
Paul Lamar
If you sent something out showing the additional tubes, I didn't get it. Can you redline them in on this picture?
I did not send it out. I sent something else out but here are both along with
the message I sent out.
The problem is the ass half is getting TOO stiff. So you have to make the front
half stiff as well. Gets too complicated to analyze with out space frame FEA.
Paul Lamar
Orginal message: **************************************************************
Subject: LEZ mount
Date: Fri, 31 Dec 2004 06:51:46 -0800
From: ACRE <rotaryeng@earthlink.net>
Organization: ACRE
Lots of snips......
If you still want to use the third Barry rubber bushing as a front mount
this might work.
Decouple the front mount beam from the rest of the structure using rod ends
or rubber bushings. As Vance is fond of quoting some English engineer: "an
ounce of rubber is worth a pound of engineering." :) Sometimes you can add
too many tubes to a space frame and wind up with undesirable side effects
such as local bending moments in joints that lead to cracks.
Again 1/4 scale balsa stick models made from 3/16th square do wonders when
it comes to understanding a particular space frame design and I highly recommend
doing one.
Paul Lamar
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