The HK 850 mm A6M5 Zero, an Article(kinda, sorta)

[Skyliner]

I planned on posting my experiences with this little Warbird

and talk to you about it. I now have already build it and flown it twice. So, here are some photos of the build process.

It is listed as an ARF on HK, but really, it is a Kit. It is also a pretty old Kit. The Zero is build for a brushed motor, it has a piece of wood sticking out the front for mounting the motor.


Because I don´t really care about brushed motors, I converted mine to fit a brushless motor. The first step for that was to cut that piece of wood flush to the foam.


Next, I grinded of the paint with some abrasive paper.


For the firewall, I cut out a 70mm x 70mm piece of plywood, drilled holes through it and widened them with files for ventilation. I also cut the corners of the firewall to match the shape of the foam.


I glued the firewall to the foam using hot glue. Well, at least now. Before, I used included contact cement. Unless the surfaces you are gluing are perfectly even, that is a bad idea. The included glue does not like to close gaps.

To install the motor, I used the motor mount as a drilling template. Small holes are all I wanted, since I used small wood screws. After the first flights, I put in some washers to get down thrust into the picture. I recommend, if your firewall looks similar to mine, you do that, too. Because the motor is mounted higher than it is supposed to be, it will otherwise pitch up quite a lot.


The servos are very easy to install. I also like the slots for them, it fits 9 gramm servos perfectly.


The push rods, though...
There are push rods included for the ailerons. BUT, mine had only one (in numbers: 1) push rod for two ailerons AND it was too short.


So, I bent some for them myself.


The push rods for elevator and rudder are OK. Use linkage stoppers for them. I had none at that moment and so I bent them into a modified Z bend.

To connect the motor to the ESC, I dug out some foam. That also helps with cooling the electronic components.


Use 1300 mAH 3s LiPos as batteries. This plane needs tremendous amounds of nose weight and the 1300 mAH 3s LiPos are the biggest thing that fits into the battery compartment. You need to grind away some foam for a perfect fit, though. I used some double-sided adhesive tape to put a piece of abrasive paper on a popsicle stick.


The canopy is secured with velcro on the fuselage. I don´t trust it. Not one second. In addition to the velcro, I used BBQ skewers to make it safe. The same thing with the cowling, though it is your choice how you attach it.


I searched the web for hours for the correct CG, in the manual it is not even mentioned. One comment on the HK article site said it 58 mm from the leading edge. I used that and on the first two flights, it seemed fine. To get there, I glued a lot of lead into the cowling. I have yet to weigh how much it actually was, but I´ll give you that info sooner or later.


Before the first flight, just to be safe, I put a bit up elevator into the radio. Because of the previous mentioned problems with the required down thrust, it instantly wanted to fly loopings. I ended up trimming the elevator on the radio all the way down. Then it flew fine. Still pitching up while throttling up, I consider programming some mixing into the radio.

Now, that is all I can tell you about that plane. If you have any questions or own that plane yourself and want to tell me something about it, don´t hesitate to post something yourself! I´m looking forward to our conversations!

Greetings,

 

[Skyliner]

Before I forget about it, here is the list of electronics and parts:

-Turnigy AE-20A Brushless ESC x1
-OrangeRX R615X DSM2/DSMX compatible 6Ch 2.4GHz Receiver w/CPPM x1
-HXT900 9g / 1.6kg / .12sec Micro Servo x2
-Robbe Mini-Servo E-COLINE 9g x1
-D2822/14 Brushless Outrunner 1450kv x1
-Turnigy 1300mAh 3S 20C Lipo Pack x1
-Yuki Model Gyro Hero x1
-8x4 Kavan Prop x1
-BBQ skewers x2

 

[Foam Addict]

Nice write up, It looks like a clone of the old (but awesome) GWS zero.

Btw, the GWS zero also has the looping problem, if you look through one of the threads, there's lots of info on how to correct that.

 

[Skyliner]

Nice write up, It looks like a clone of the old (but awesome) GWS zero.

Btw, the GWS zero also has the looping problem, if you look through one of the threads, there's lots of info on how to correct that.

Hey Foam Addict,

this is indeed what I read about this plane. The mold seems to gone through many different companies. The oldest one is GWS, the box says AMAX Hobby, the decals say Guanli and it is now sold by Hobby King.

I did read through some forum threads, they all seem to say to put downthrust into the motor. I´m glad I figured that out myself.

I have to put some batteries through it now, to say if that helped.

Greetings,