[NSRCA-discussion] Serious Torque on the Nose of the Model - RESUBMITTED

[kaoromero at aol.com]

Charlie, buy a YS!... Juan


-----Original Message-----
From: Charlie Barrera <charliebarrera at consolidated.net>
To: nsrca-discussion <nsrca-discussion at lists.nsrca.org>
Sent: Tue, Dec 4, 2012 8:03 am
Subject: [NSRCA-discussion] Serious Torque on the Nose of the Model - RESUBMITTED



I torqued the nose off of the fuselage of my WindS Pro. I have a 2 meter WindS Pro which I recently acquired from a good friend. The model is probably 2 years old and has close to 200 flights. The model had a contra rotating propeller power system installed before I acquired it. The nose section had been modified to accommodate zero degree down thrust and zero degree right thrust. I installed a new Hacker Q80 motor on the nose, attaching it to the nose ring. I did not reinforce the rear of the motor to the fuselage. I re-modified it for 2 1/2 degree right thrust and 1 degree down thrust.  I reinforced it amply and was confident in the installation.
 
I made a normal takeoff at about half throttle. As I turned to a right downwind, I powered up to about 3/4 throttle for my usual trim pass. I was in a right bank, and was rolling to the right. I heard a very loud "whack" noise. I continued my turn and only then did I realize that something had changed. I managed to land the model, not realizing that I had lost the motor. It was difficult landing because of the resultant aft CG. The fuselage was missing the first 4 inches.  It was also very apparent that torque had sheared the motor off the fuselage.  I theorize that the combination of the right roll and the power up caused a gyroscopic effect on the model, shearing the nose off the model.
 
I wanted to share this to possibly alert others to a nose ring installation of their high power motors. Be aware of the forces that can be produced by these high torque motors. I don't know whether providing a rear brace on the installation would have made a difference. I don't think so. The fuselage was "torn" well behind where the rear brace would have been.
 

 
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