Tuesday, May 19, 2009

China Funjet

Recently i acquired a China-manufactured Funjet from AerialHobby. Although it's called 'Funjet', there are some distinct differences in the looks department between this and the Multiplex version. I will cover the differences between the 2 in this post.

The left one is the Multiplex Funjet and the one on the right is the Skyatech Funjet (China).

Differences :
1) Size
The Skyatech funjet is larger in overall size. This is due to the larger wing area of the Skyatech version. As a result, it is a great floater. I can cut my throttle during flight and it would glide in the air for ages! Therefore, landing is pretty easy with the Skyatech version.

2) Canopy / Internal housing compartment
The canopy of the Skyatech funjet and internal housing compartment is HUGE! I am talking almost the entire top of the plane is the housing compartment! There is some much room inside that you can place your batteries, ESC and receivers almost anywhere to setup your CG point! Don't get me wrong, the Multiplex Funjet also has a lot of housing space as it is based on long-and-narrow concept, but half of the Multiplex version is difficult to access because the canopy only covers half of the plane while the other half is pretty much CA-ed onto the plane. For the Skyatech Funjet, the entire top of the plane is basically the canopy! So access to the electronics is very easy and setup is simple as well!

Unfortunately, because of the large canopy size, it does not not clip-on to the body very well. I have seen many canopies of the Skyatech flew off during flight. So i would strongly recommend to find an alternative way to secure the canopy, like using magnets, or velcros etc..

3) Motor mount
The Multiplex version has a great motor mount in my opinion. The motor is housed inside the fuselarge and it is protected. The Multiplex version also a motor mount which enables flyers to adjust the trust angle easily by turning a single screw. The housing design is also large enough to house motor size from 20 - 36mm sized motor easily.

The Skyatech funjet is simply a metal stick mount screwed onto a plastic holder and in return, CA-ed on the back of the plane. Again, i strongly recommend to remove the plastic holder and re-CA once again as i discovered that the factory did not put sufficient CAs to hold the plastic holder down in place. You wouldn't want the entire motor mount to dislodge during flight! Trust me on that one... You can see from the photo that the motor will be exposed based on this design and there is no easy or straight forward way to adjust the trust angle.

Due to the small metal stick mount, i found out that it can only hold motor size of 28mm at maximum. And if you are using a 28mm rated-size motor with heatsink, the effective diameter of the motor would exceed 28mm and you can forget about using the stock mount as it will not fit at all!

4) Wing Reinforcement
Multiplex funjet comes with a plastic long tube which runs across the wings to act as reinforcements to prevent the wings from warping or breaking during high-G manueovers.
Unfortunately, the Skyatech version does not come with any reinforcement rods, although there are already pre-cut groove on the wings. So you should purchase carbon rods of about 3mm in diameter size and fit it into the wings of the Skyatech funjet as additional reinforcements.

Well, that's about all i can tell in terms of differences. Flight report coming up next...

Wednesday, May 6, 2009

My latest addition! A TRex 500 Clone! (JY500)

After flying 450-sized helis for 3 years, I finally 'upgraded' and got myself a TRex-500 clone. It's called the JY500. I bought this from www.aerialhobby.com, a local online hobby e-store. It's a replication of the famous T-Rex500 (Carbon Fibre) Edition. It completely identical in every way to the original Align one but this is like 3 time cheaper!

It's a full metal head assembly, carbon fibre frame and a fibre-glass canopy.
It does not come with any manual but this was not really a problem as i can simply download the Align's TRex500 manual and use it to assemble the heli since it is an exact replication.

First impression is that a 500-sized heli is substantially larger than a 450-sized heli. I mean, this thing is huge in my opinion! I should have taken a shot by putting my 250, 450 and 500-sized heli together so that the size comparison can be seen.

My electronic setup are as follows :
Cyclic Servos : Hitech HS5245MG
Rudder Servo : Futaba 9254
Gyro : Align GP750
Motor : Scorpion HK3026 - 1600KV brushless with 13T pinion

This setup , coupled with a 6S2650 Zippy Flightmax Lipo battery gave me plenty of power for 3D manuovers and a good 5 mins flight! The heli seems more stable than a 450 sized one. I have more time to correct my inverted hover. As I haven't had too many flights on this heli yet, plus I am 'running it in' currently, I haven't been able to do the other harder 3D moves like tic-toe, stationary rolls, flips yet.... but soon.... :)