When I received my new Align TN70 Top Combo Kit around 3 months ago, I noticed excessive runout on this particular gear. When placed on the main shaft and hand rotated, there was as much as 2mm of oscillation along the edge of the gear. I wasn’t sure if had accidentally received a molded gear that slipped past quality control at the Align manufacturing facility or if there was an inherent design flaw in the injection molding of this particular part. I constructed the helicopter utilizing the warped gear in the kit and noticed significant vertical tail rotor oscillations and vibration in hover and mild flight regimes. As soon as replacement spares were available for this part, I placed and received an order for 3 additional gears. When these arrived, I checked each one and was surprised to see that all exhibited some significant amount of runout. I picked the gear with the least amount of deformation and will check to see if my vibration issue improves. Align may need to redesign this particular gear and change the size and number of spokes radiating from the hub and supporting the gear ring. A more stable polymer may be needed in the injection molding process too. It is very easy to flex this component in your hands and the distortion of the newly manufactured part may be occurring during the cooling period immediately after the hot gear has been removed from the mold.
I would like to thank HeliDirect for their fast response excellent service and plan on using them as my primary helicopter vendor in the future.
Mike M. Macon, GA
