From the December 2011 issue of Model Airplane New
Construction photos taken by Michael Gross, Finished and flying photographs taken by Sal Cavagna
There were some 11,000 Zeros built in many different variations between 1940 and 1945. I chose the Mitsubishi A6M5c Type 52 Hei to model because I purchased a highly detailed 1/48 scale model from Hasegawa hobby kits modeling that plane with a unique paint scheme. There were 6,000 Type 52 Zero fighters produced towards the end of the war. The Type 52 had many upgrades from earlier Zeros including more armor plating around the pilot, individual exhaust stacks to produce thrust, and an improved armament package. The two 7.7mm machine guns in the cowling were replaced with one 13mm machine gun. I felt this would give my zero a distinct look with an omitted gun in the cowl. This particular plane I modeled from the 721st Naval Air Group JINRAI Fighter Squadron, February 1945, also had two 20mm cannons in the wings. Unfortunately for the Japanese, these “improvements” to the Zero actually made it heavier and therefore less maneuverable. Maneuverability was the feature that most set it apart from allied fighters at the beginning of the war.
I found the origin of the name Zero quite interesting. It was not the allied code name for the plane which was “Zeke”, nor was it because of the red circles on the wings and fuselage. Zero comes from the Japanese Navy designation, Type 0 Carrier Fighter, or Rei shiki Kanjo sentoki in Japanese. The zero or rei in the designation was taken from the last digit of the Imperial year 2600(1940). In Japan the plane was unofficially called the Rei-sen and became known to the world as the Zero Fighter.
I remember as a child watching my father fly his forty sized Zero at airshows and funflys thirty years ago. It was my favorite warbird then and still is today. I knew my first giant-scale warbird would be a “Rei-sen”. With this being only my third giant-scale model and my first giant-scale warbird, I wanted to be sure the build would be straight forward and the finished product would fly well. I decided on the Ziroli Zero because I have seen many of the Ziroli warbirds fly, and they all fly great. Also, I have spoken to many modelers who have built Ziroli models and they all praised Ziroli’s construction methods. .
I started with a set of plans, fiberglass cowling and a plastic canopy from Nick Ziroli plans. The plans have templates to cut all parts, but I chose to purchase a wood kit from Precision Cut Kits to save some time. It is a good idea to have the landing gear you plan to use before you start the wing. I purchased a set of robart retracts and wheels from Nick Ziroli Plans and started the wing. The wing was built in two halves over the plans and everything fit together nicely. Once the basic structure was complete I installed the gear blocks and the landing gear. Be sure to check the angles and the depth of the gear before you glue the blocks in.
Once I joined the two wing halves, it was time for sheeting. I made complete wing skins by butt-gluing the balsa sheets with pink ZAP. I glued the bottom sheets on using green ZAP and the top sheets were glued on using yellow wood glue. I used everything from pins, tape, and a stack of books to hold the top sheets in place. After the wing was sheeted I set it aside.
Next I built the horizontal and vertical stabilizers over the plans and sheeted them like the wing. After building all of the control surfaces they were set aside. The fuselage was next, and many people warned me about building the Zero because you have to build up the fuse. Most models today, including the Ziroli warbirds, have available fiberglass fuselages. In a time of ARFs and pre-made everything, I was looking forward to building a fuselage “old school.”
First you build a crutch and slide the formers onto it. The crutch will be raised above the board using blocks or boards about five inches high. Be sure everything is square and secure before you start gluing. Once the formers are in place, you can ad the stringers and the 1/8 balsa sheets. The planking can be a little tedious, but the more time you spend making each piece fit now will save you from using heavy filler later. After the fuse was mostly sheeted I added the vertical and horizontal stabs. Sheeting was pieced in and the sanding began. It was not as hard as it sounds, and it actually was a rewarding experience watching a Zero come to shape.
The only area I veered from the plans was installing the engine. Although many engines around the 60cc range would fly the Zero fine, I wanted a fast warbird. I decided to go with a 3W-75i with a rear induction carb from Cactus Aviation. There was no provision for this installation on the plans, so I turned to my father, Mike Gross, to come up with a solution. He designed an airbox that is integrated through the firewall and into the second former. It is a neat and strong design with the sides interlocking with the top and bottom. The airbox houses the carburetor which extends some four inches into the fuselage. This also allowed for short precise linkages to operate the throttle and choke. I decided on a pitts muffler because I like how they sound. It is rather bulky, but it only sticks out on the bottom with the cylinder head. The airbox extends about two inches outside the firewall. This provided space for two batteries and the ignition box avoiding extra lead in the nose.
I made the gear doors out of fiberglass using the old monocot method over the wing. First, I put a layer monokote on the bottom of the wing and laid up a couple of layers of fiberglass cloth and epoxy. After letting it dry, I pulled the fiberglass “squares” off of the monokote and pulled the monokote off of the wing. This gave me the proper contour of the wing for the doors and I cut them out to shape. It is important to remember to do this before you cut out the wheel wells in the bottom of the wing sheeting.
I wanted the outer gear doors to look scale. I realized I could not use one piece doors because they would hit the ground as the suspension collapsed. Often times, modelers shorten the doors to allow for suspension travel, but I wanted the doors to cover most of the wheel like the real one. I used references from various books to copy the original design. I split the doors at the scale location and mounted blocks to the strut using epoxy and small straps. I drilled and tapped the axle for the lowest mount. The lower portions of the doors overlap the uppers by about ¼ inch. When the suspension travels the lower door travels as well.
The exhaust stacks on the A6M5s are a prominent feature. I used photos of real Zeros to determine the size, shape, and location of the exhaust. I experimented with ½ inch aluminum tubing and a propane torch to get the right bends. This was a matter of trial and error, for with too little heat the tubing would crease and two much heat resulted in the tubing melting. Once I got the curves right, I use a small hammer to flatten them out to an oval shape. They are mounted on blocks on the firewall and extend out through cutouts in the cowl flaps. I painted them flat black and then lightly sprayed some red-brown paint over the black. This gives a nice illusion of rust.
COVERING AND FINISHING
In finishing the surface, I used 1-ounce fiberglass cloth and Pacer Z-Poxy finishing resin. I applied two coats of filler primer with a foam brush and sanded most of it away. Then I sprayed the model with automotive primer. When I was satisfied with the surfaces, I laid out the panel lines using drafting tape and primed over the tape. After the prime was dry I pulled the tape away revealing the panel lines. Be careful not to leave the tape on too long because the tape residue may be left behind. This happened to me on the wing and it took a lot of time to clean the glue off.
I painted the Zero with custom-mixed KlassKote epoxy paints. This paint system is easy to use and the finish is strong and smooth. All markings were painted using paint masks custom-made by Red5designs. I experimented with pastels and a silver sharpie marker for the weathering, and cleared everything with Klass Kote clear.
IN THE AIR
After a year and half of building, I was ready to fly the Zero. The first flight went well. Takeoff requires a good amount of right rudder, and it is better to ease on the throttle to get her going straight. Once airborne, I retracted the gear and pulled out will plenty of power from the 3W-75i. I had to add about a ¼ inch of down elevator trim, but all the other controls were centered and the suggested throws worked well. With the flaps fully extended, the model wanted to pitch up quite a bit. I mixed some down elevator with the flaps and now it flies in a slight nose down attitude with full flaps. The model performs all maneuvers well and makes impressive strafing runs over 120 mph. The Zero lands very nice with the flaps and ground handling is excellent with the wide stance of the landing gear.
I have accumulated over 100 flights with the Zero. With only a few minor things to be tightened up and adjusted, it has been mostly problem free. This project was well worth the time and effort. It is quite exciting to fly a giant scale warbird in formation with three or four of your buddies at over 100 mph!
Engine – 3W-75i
Radio – JR 9303 2.4, hitech servos
Gear – Robart retracts and wheels
Propeller – Mejzik 22×12 3-blade carbon fiber
Model: Mitsubishi A6M5c Type 52
Distributor: Nick Ziroli Plans
Wingspan: 91 in.
Wing area: 1,400 sq. in.
Length: 73 in.
Weight: 28 lb.
Hasegawa Hobby Kits; dist. By Squadron (877)-414-0434; squadron.com
Nick Ziroli Plans; (631)-467-4765; ziroliplans.com
Precision Cut Kits; (609)-538-1388; precisioncutkits.com
Pacer Technology; (800)-538-3091; pacertechnology.com
ZAP; (800)-538-3091; zapglue.com
Cactus Aviation; (520)-721-0087; cactusaviation.com
Robart mfg.; (630)-584-7616; robart.com
Klass Kote Epoxy Paints; (612)-243-1234; klasskote.com
Red5designs; (631)-281-7633; red5designs.com
JR; dist. By Horizon Hobbies (800)-338-4639; horizonhobby.com
Hitec; dist. By Tower Hobbies (800)-637-6050; towerhobbies.com
Mejzlik; dist. By Nick Ziroli Plans
Nick Ziroli Plans, 2231-22 5th Ave., Ronkonkoma, NY 11779; (631) 467-4765; www.ziroliplans.com