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

[Earl Haury]

To add to this, the plate should be strong enough so as to not flex - all 
the flexing should be in the gear. When the plate flexes, bending forces are 
applied to its attachment point(s) to the fuse - this is really bad for 
composite fuse structure. The simple way to check for plate flex is to grasp 
the gear near the wheels and apply pressure up and out - similar to 
experienced in landing (the more forcefully you land the more you should 
flex the gear) and watch the plate for flex. Pretty much all plate materials 
will flex in a wide fuse. The easy fix is to make the plate into a "T" or 
"U" (channel) by adding a 1/8 x 1/4 carbon bar(s) across the plate, but 
other materials will also work.

Earl
----- Original Message ----- 
From: <aeroslave at tx.rr.com>
To: <nsrca-discussion at lists.nsrca.org>
Sent: Monday, January 19, 2009 8:39 AM
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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