by: Pete Becerra [ ]
Originally published on:
The Bell AH-1Z Viper attack helicopter, based on the AH-1W SuperCobra, was developed for the United States Marine Corps as part of the H-1 upgrade program. The AH-1Z features a four-blade, bearingless, composite main rotor system, up-rated transmission, and a new target sighting system
The blades are made of composites, which have an increased ballistic survivability, and there is a semiautomatic folding system for storage aboard amphibious assault ships. Folding blades and tail sections are perhaps the most physical attributes of a helicopter, especially in the military, that has been prepared for service at sea, usually for ship-borne operations where hanger space is at a premium. The rotors can sustain a 23mm round direct hit. The rotor design has eliminated all bearings, hinges and rotor-mounted vibration absorbers. The blade body consists of a spar assembly, leading edge protective strips, skins over a honeycomb core and a trailing edge strip. Blade folding is by a combination of automatic and manual procedures. The system is capable of folding and unfolding in horizontal winds up to 45kt from any direction.
Academy released an AH-1Z Viper a few months ago. Although a great kit with great detail, it lacks the option to fold the rotor blades. Well, Legend Productions has come to the rescue in the form of a blade folding conversion kit. Iíve only found one modeller on the web who attempted and did a great job of folding the blades without using the Legend kit.
What Legend has done is basically taken the original rotor blade parts from the kit and done all the cutting for you. The kit only consists of 8 parts and a small razor saw does the rest. On the real rotor, only two blades fold, hence the small parts count in the kit. Included are two replacements for one each of kit parts D5 and D6. After careful cutting, the kit gives you two more replacement parts for two D1 parts. On the folding blades, kit part D34 is replaced by a complete D34 in the Legend kit. Also, in the Legend kit are actuator motors that move the locking mechanism for the two folding blades.
As I was saying, Legend took kit parts a cut them all up for you and re-casted them. It seemed like Academy knew that us modellers would try and make the rotors foldable, so where you have to cut did not take away from any detail on the blade. On part D1, you cut right where the blade ends and sand away the detail that is left on the blade. After cutting, itís just a matter of sandwiching the blade between the new D5/D6 and its corresponding half. You have to drill out the holes in the two blades before you sandwich them between replacement D5/D6 and corresponding halves. The replacement blade halves were a good fit and required just a little filing to remove the seam. Add the hinge lock mechanism and motor and all is done.
****NOTE**** Make sure you include part C6 when gluing the two replacement halves. Donít do what I do and glue the two halves with the blade but without part C6.