Need a 450 Motor? look here http://www.hobbycity.com/hobbycity/store/wikishow.asp?idwiki=133

Cant go wrong!

The HXT900 servos have now got shorter leads and are no longer suitable for a 450 Heli. Hextronic 14g metal for double price is now good value

Ehirobo.com selling CopterX V2 Full Metal $59 + delivery smashing the HK450 for $9 you get the rest of the CopterX Heli, not just metal Head and Tail!

Building RC Helicopters

Blade Pitch Gauge

Take me back to the tools menu

What They Are and What They Are Used For:

A blade pitch gauge is used to measure the pitch or angle of attack of the blades.

How to use them:

Adjust the pitch gauge to the desired measuring angle (eg 0 degrees, 9 degrees etc).  Slide them over the blades then use the pitch gauge’s clamp to grab the blade.

IMPORTANT:  Be careful that the pitch gauge is exactly perpendicular to the blade when viewed from above.  If off at an angle, the reading will be false.

IMPORTANT:  Make sure the fly bar is level.  If it is not level, due to the mixing arms the rate of change of the angle of the fly bar will change at a different rate to the blades – so inaccurate results will occur.

View along the edge of the pitch gauge to the fly bar.  If they don’t line up exactly, adjust the linkage rods/tx settings till they do.  Now do the other blade and repeat till they are consistent.

For more detail, refer to the links below:

http://www.heliguy.com/Forum/how-to-use-a-pitch-gauge-t2312.html

http://www.helitown.com/PitchGuage.html

http://www.raptortechnique.com/pitchgauge.htm

Blade Balancer

Take me back to the tools menu

Blade balancing is a whole separate subject, but you will need accurate scales as part of the process.

Some guides from the web on blade balancing:

http://www.dream-models.com/eco/Blade_balancing.html

http://www.trextuning.com/bladebalancing.php

http://www.rc-airplane-world.com/rotor-blade-balancing.html

BLADE BALANCER

What They Are and What They Are Used For:

Making sure your blades have the same centre of gravity.  Note that even blades of the same weight may have a different CoG due to manufacturing defects, thickness of paint etc

There are a number of types of blade balancers from the simple ones shown on the left to bed style ones on the right, right through to magnetically suspended ones.

How to use them:

Refer blade balancing links in previous section

The pair of blades to be balanced are put in either side of the balancer.  If a simple balancer like the one on the left is used, a pair of blocks need to be provided for the balancer to sit on.

The side the balancer tips to is the heaver side, so some form of compensation (eg tape) is added to the lighter side.

Scales (0.1g Resolution)

Take me back to the tools menu

What They Are and What They Are Used For:

The head on an 450 sized electric heli spins at anything form 2200 to 400 RPM.  Any difference in weight of the blades or other parts will result of an out of balance – and hence a bad wobble, making the heli less stable, harder to fly and use more power.

Scales can be used to measure the following to make sure the weights of both items in the pair are the same:

• Main blades
• Tail blades
• Fly bar paddles
• Fly bar weights

How to use them:

Turn them on.  Put things on them.  Note what the scales read.

Swash Plate Leveller

 Take me back to the tools menu

What They Are and What They Are Used For:

Swash plate levellers are used to make sure that the swash plate is exactly perpendicular to the main shaft when the controls are centred (ie your Tx’s sticks are in the middle).

Have a level swash plate is critical to having a stable heli in hover – any tilt on the swash plate will mean the heli has a thrust bias in that direction and the heli will want to accelerate in that direction.

How to use them:

Remove all of the upper head assembly above the swash plate, so there is just the swash plate and the main shaft installed on the heli.  

Slide the swash plate leveller onto the shaft and down till it rests on the swash plate.  Adjust the sub-trims on the servos till the swash plate is exactly level / touches all three arms on the leveller tool.

NOTE – a swash plate leveller is not essential, but will help in getting a better set-up on your heli.

Verniers

 Take me back to the tools menu

What They Are and What They Are Used For:

Verniers are used for accurate length measurement.

The length of the linkages on the helis controls are critical – so being able to accurately measure (to within 0.1mm) is vital to setting the heli up properly.

Digital verniers are not compulsory, but they make life much easier and aren’t too expensive these days.

How to use them:

Verniers have jaws for measuring both outside and inside dimensions.  Open the jaws to match the length of what you are measuring, then read off the length.

Linkages can be measured by the overall length, centre of the ball or rod length.  The heli manual usually gives recommended lengths for all linkages to start with.

Measure the linkage, then use the ball link pliers to disconnect, then screw the linkage to adjust.

Verniers are also used to make sure the fly bar is installed exactly central, and that the fly bar paddles and fly bar weights are equally spaced from the centre of the main shaft.

Ball Link Pliers

 Take me back to the tools menu

What They Are and What They Are Used For:

These are special pliers for undoing and doing up ball joints on the connecting control linkages.

Examples of the connecting control linkages in the swash plate:

Helis use connecting rods to connect the various linkages and control surfaces.  As these need to move in multiple axis’s, a ball joint is used at the end of the linkages. 

Each joint is made of two parts – the ball and the linkage end.  The linkage end has a threaded hole that a threaded rod goes into.  By screwing the linkage end on the rod, the length of the connecting rod can be changed – which will then adjust the control connections on the heli.

IMPORTANT – the linkage ends have an “inside” and an “outside”.  The inside has a larger hole, and is the side that should be pushed onto the ball.  Some linkages have a marking on the linkage showing which is the outside of the linkage.  For example Align linkages have an “A” on the outside face.

How to use them:

Ball link pliers can be used to push the linkage onto the ball, remove the linkage from the ball or hold the linkages when adjusting them:

http://www.ehow.com/video_4412030_using-ball-link-pliers-rc.html

HEX Drivers

Take me back to the tools menu

What They Are and What They Are Used For:

These are like screwdrivers but with hex heads (like allen/hex keys).

Small model helis just about exclusively use hex head screws.  You will forever be undoing and doing up these small screws.  A good hex driver will change this from an exercise in frustration to a pleasure, and decrease the chance of damaging either the screws or the driver.

For a HK 450 (and most 450 size helis), just about all the screws are 1.5mm.  The other size needed is 2mm for the blade grip bolts.  If you are on a real budget you could get away with getting a good 1.5mm size only, but a set of sizes is recommended.

IMPORTANT – do not think you can get away with just using allen keys (ie the L-shaped hex keys).  These are commonly of poor quality.  Also lots of the screws on a heli go into plastic – so it is important that you don’t over tighten them.  A hex driver will give much better ‘feel’ to how tight a screw is – so you are less likely to strip the thread.

Try to make sure the ones you get are of the hardest steel possible.  This way they won’t wear over time and are less likely to slip and strip out the hex heads.

How to use them:

Just like a screw driver

Dx7 Gyro Setup 

I created this video that explains a simple setup of a gyro on the Dx7

rel="nofollow" >

XmHobbies Gro or DealExtreme Gyro

Well look at the video it says it all, but I got this gyro and pulled it apart and found it was identical, also when I mounted it onto my HK450 the gain was also exactly the same as was the travel adjustment.

Regards

Elias Gourvelos (EatAtJoes)

Gyro Mounting Which Way

Well this is a simple video to explain how a gyro reacts, you have probably seen gyros mounted on the side of a heli and some underneath well it all comes down to which way the gyro reacts. Look at the video and then you will understand what I mean. Then once you work out which way it reacts you mount that reaction angle parrallel to your rotor blades, it doesnt matter if it’s at the front of the heli, the back of the heli top or bottom of the boom mounts that is, but so long as you mount it the correct angle, if it is wrong then the moment you tilt your swashplate you tail will spin into a piro and flip the heli around and you WILL CRASH, so make sure it is correct, and ask ask ask, most gyro have the writing and adjustment pots face the ground / or the sky depending if you mount under or over, but there is no upside down for a gyro just horixontal or vertical, work out which way it reacts and imagine your heli turning in that direction then you want the servo reacting in the opposite direction well your tail really…

Regards

Elias Gourvelos (EatAtJoes)

The HK450 where do you get it?

For those who dont know where you can buy the HK450 RC Helicopter well it can be found here

This is by far the cheapest Trex 450SA clone available on the market today.

The HK450 online Forum at RCgroups

This is where you will find me and so many other chatting about problems, issues, resolution, fixes, recommendations, debates, and many more things relating to the HK450 rc helicopter.

We have a large variety of skill sets and experiences in the forum, I strongly suggest you take some time to read through the posts, however it will be like reading a large book because there are so many pages.

Simply click on the link below and select last page for the last comments.

Can be found here

Linkage Lengths for the HK450 Helicopter

These are the recommended linkage lengths for the Trex SA which is the closest to the HK450 Helicopter.

Description of lengths

A) Main blade grip to mixing arm linkages, two required:

Rod Length 9.0mm
C to C Length 20.0mm
Overall Length 26.5mm

B) Flybar control cage to washout arm linkages, two required:

Note: These linkages come factory assembled and installed. However, be sure to confirm their length and adjust as necessary before proceeding.

Rod Length 12.5mm
C to C Length 23.5mm
Overall Length 30.0mm

C) Mixing arm to inner swashplate linkages, two required:

Rod Length 32.0mm
C to C Length 42.0mm
Overall Length 48.5mm

D) Pitch servo (front right) arm to outer swashplate, one required:

Rod Length 33.0mm
C to C Length 46.0mm
Overall Length 52.5mm

E) Elevator servo (rear) arm to outer swashplate, one required:

Rod Length 28.0mm
C to C Length 41.3mm
Overall Length 46.8mm

F) Aileron servo (front left) arm to outer swashplate, one required:

Rod Length 19.0mm
C to C Length 32.3mm
Overall Length 37.8mm

Bob White known in in the industry as Bob Finless has created this video Electronics 

In this video Bob shows a way to mount the electronics in a 450 class heli, it’s not the only way to mount the electronics but I can say that I mounted my devices in the same way before seeing this video simply because it balanced the heli better.

I recommend viewing this video, but also suggest to mount the gear where you find a good balance point and no obstruction to other equipment.

For example if you are mounting a Logger into the Heli then you need to re-think the locations used, what I do is set the heli up between two glasses resting the flybar on the top of the rim of the glasses and start adding and moving devices until my heli is balanced.

Regards

Elias Gourvelos (EatAtJoes)

Bob White known in in the industry as Bob Finless has created this video Ball Links 

Bob White known in in the industry as Bob Finless has created this video Installing Servos 

Bob White known in in the industry as Bob Finless has created this Gyro Setup Video

In this video Bob explains how to correctly setup your Gyro.
The Heading Hold and Rate Modes are explained as what effects they have on the  heli.

I recommend viewing this video as it will help eliminate tail drift if your gyro is incorrectly set.

Regards

Elias Gourvelos

Green Loctite HK450 Tail Gear Fix

I was at a field one day with my new HK450 heli and was doing some pop up when the tail gear assembly slipped sending my helicopter into a wild piro as I was going up, I immediately backed off the throttle and regained a little tail still spinning mad but I managed to land the heli without any damage.

I pulled apart the heli to discover that the tail gear had slipped, so I went about changing the gear but before I did I pulled against the gear to see if I could make it move, well the result was scary, just with finger pressure I was able to pop the gear from the shaft, so I went about getting some green loctite and found that it held perfectly, never to move again, even to the point of using a vice to apply pressure I found that the gear would start to show signs of snapping off but no signs of it moving from the shaft, I then proceeded to fix all my other spares in the same way and recorded what I found which is shown below in the video, needless to say I wasnt the only person who had suffered the tail gear slip, but now everyone is using my fix to the gear and not one person has had it slip since doing this mod.

I highly recommend you do this before you fly.

Regards

Elias Gourvelos (EatAtJoes)

Turnigy Plush 40A ESC 3A BEC for the HK450 Heli

I was curious about the performance of these cheap ESC’s and pulled it apart only to discover that the ESC was a lot more than I expected.
These Turnigy Plush ESCs are perfect, they use a switching technology to provide the output for the BEC and still call it a linear output, to put it simply it is a buck converter circuit and it is capable of supplying all the current you need for your servos gyro and receiver.

Take a look at the video and see for yourself this is a quality built ESC, oh and dont worry I simply finished off the ESC by putting some more heatshrink back on and it has been flying ever since.

Regards

Elias Gourvelos (EatAtJoes)