[NSRCA-discussion] Mo'CF gear talk from AeroSlave

[Dave]

Gray,

Yes, I agree the front of the gear plate is tensioned, and the rear is in
compression.

>From side to side, the middle of the plate sees a bending load (gets lower
in the middle on landing loads) with typical 2 piece gear.  With the
overlapping 2 piece gear from Wistmodel, the gear carries the bending load.
The bending load is partially carried by the center section of one piece
gear.

So far as failures, the most common is certainly when the front of the
landing gear plate is ripped downwards out of the fuse.  However, I have
also seen plenty of gear plates that were well gusseted and braced on the
fuse edges, and cracked front to back right in the middle of the gear plate.

Regards,

Dave

-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of
aeroslave at tx.rr.com
Sent: Monday, January 19, 2009 9:39 AM
To: nsrca-discussion at lists.nsrca.org
Subject: [NSRCA-discussion] Mo'CF gear talk from AeroSlave

Dave

Concerning your earlier email

"I am not a fan of the typical 2 piece gear - where each half stops short of
the middle, and a nasty bending load is created in the center of the gear
plate (unless a spreader plate/joiner is attached between the two legs). "
--

Here's how I see the stress...

On a landing, hard or soft when the gear impact, the load will be tension on
the bolt closest to the edge of the "Half gear". Bolts work really good in
tension. The other load is the bending back of the bolts-a load at which
bolts suck. So a rough landing using a two piece gear wants to either pull
the bolt through its mounting  in the plane (cuz 11lbs ain't gonna tension
fail the bolt) or its gonna bend the bolt heads ...resulting in a semi
tension on the plane bolt mount, wanting to once again pull it through. What
happens in reality is the bolts do not break, but the entire mounting plate
is stress tension up front, compression in the rear until it find sthat weak
"terminated area" and rips out at that point. My whole thinking here is that
regardless of a 1 piece or two piece design, the weak link to failure lay
elsewhere-so 1 or 2 piece does not matter. Speaking of failures.......

Anyone who has had a gear failure...please let me hear it. Describe the
landing (wasn't a 10 now was it???? be honest)  describe the
failure...bolts,  plane mount, fuse sides, gear break..whatever.

My landing are always scored about 9.24-9.56, which is why Lance is testing
the prototype gear.

Gray 

AeroSlave Dude #2 (Lance is #1-I default to him) 

AeroSlave
4408 Elmhurst Dr
Plano, TX  75093
www.aeroslave.com
PayPal: aeroslave at tx.rr.com
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