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