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In my zeal to get started on my first multirotor I forgot to add a prop balancer to my cart! So I set out to make my own out of parts I had laying around...

My first prototype used a wooden drill bit because it fitted my prop perfectly at 6mm in diameter. Unfortunately because of the shape of the drill bit it would tend to one side, rendering any balancing done to the prop useless.

Learning from experience, I decided to go for as little mass as possible. A needle fitted the job description.

Next problem: How do you get a prop with a 6mm central hole to center on a needle? My answer came in the form of heatshrink tubing. Using very short lengths of heatshrink which I cut very carefully using a scalpel to ensure they were consistent I eventually got enough layers to slide the prop on.

Because heatshrink shrinks to the center, the prop is perfectly centered.

The key is to have as little mass as possible on the spindle. Using longer lengths of heatshrink produced an unbalanced spindle.

Below is a rough guide to making one of your very own using commonly available parts...

Please take not that I am not responsible for anyone's actions, use common sense!

Materials:

    1x Large needle
    2x Strong Magnets
    1x Piece of wood for the base
    2x pieces of wood for the walls
    4x L Brackets
    8x short wood screws
    Lengths of small diameter heatshrink

Tools:

    drill
    dremel
    heatgun
    metal Shears

Step One:

Take your needle and shear off the eye. This can be hard so be careful and make sure no flying bits of metal hurt any one!

Step Two:

Put the needle into the dremel sharp end first. Now grind down the sheared end into a fine point using metal sand paper or on a grinding disk. This too can be a challenge because this stuff is harder than diamond.

Step Three:

Attach the two pieces of wood at 90 degrees to the base piece of wood using the L Brackets and the short wood screws.

Make sure the distance between the walls leaves enough room for the needle and two magnets. Also check that the walls are high enough so that the prop can rotate 360 degrees around.

Step Four:

Hot glue the two magnets to the walls, but be careful because magnets with molten glue on them have a tendency to snap together right onto your thumb leaving a nice burn, ask me how I know... :) .

Make sure that you hot glue the magnets facing each other so that they want to attract (north facing south or visa versa).

Tip: Magnets can be found inside microwaves and old hard drives.

That should be it! As you can see below there is virtually no friction between the needle and the magnets.

So now I am curious, I have spent the afternoon with my RCTimer Carbon Fiber props on the balancer and have been researching the best way to balance props, so I ask: How do you balance your props? More specifically what is best practice when it comes to balancing carbon fiber propellers?

As you can see in the picture below I have some copper tape strips to work with, but I am afrade that they will corrode plus they are an eyesore.

The best I have seen comes from U.A.V Advertising: https://www.youtube.com/watch?v=a3Byk8W5P_E

This method involves sanding the trailing edge of the prop.

I am planning on balancing my hubs as well as my brushless motors using lead tape.

So I put it to the community... what methods do you recommend? For those who advocate the tape method, what brands of tape have you found work best? For those who are in the glue/varnish camp, could you provide more detail?

Happy balancing!

Jethro.