In this section we’ll be balancing and mounting the props.

What I’m using and why

Before we talk about prop balancing, I’m going to go over what I’m using and why. There are two types of prop balancers you can buy. There’s the magnetic kind which are cheap, but don’t work very well, and then there’s the mechanical kind which work good, but cost more. I personally like the mechanical ones because they’re balanced well and work every time. The prop balancer I’m using can be found on eBay for a reasonable price. If you’re on a budget and you’re thinking about buying the magnetic balancer, I would read this forum before buying one. In my opinion, the magnetic balancers are a waste of time.

 Prop balancing

Screen Shot 2014-02-13 at 10.28.19 PM

First, mount the prop to the balancer. Once the prop has settled, you should notice how one side will always drop down. Whatever side that falls down is the side that’s too heavy.

 

Screen Shot 2014-02-13 at 10.28.31 PM

Once you’ve determined which side is heavier, apply some tape to the opposite side to counteract the extra weight. When you let go of the prop it should no longer fall to one side.

Prop balancing is not always necessary when you buy good props. On the other hand, if you buy bad props it can be tricky if the hub is not balanced.

 

Prop mounting

Screen Shot 2014-02-13 at 10.28.42 PM

The diagram above shows what direction the motors should be spinning in. If your ESC’s are hooked up correctly and your motors are not spinning in the proper direction, you can reverse any of the three motor wires.

The props should be mounted in this order

  1. (blue) clockwise prop
  2. (Red) counterclockwise prop
  3. (blue) clockwise prop
  4. (Red) counterclockwise prop

The easiest way to tell if a prop is counterclockwise is by looking at the letters and numbers on it.

  • Hobby King props that come in matched pairs usually have the letters L and R at the end of the name witch stand for left and right.
  • APC multirotor props have the letter P at the end witch stand for clockwise (counterclockwise props do not have the letter P).
  • HQ props have the letter R at the end witch also stand for clockwise.

 

Screen Shot 2014-02-13 at 10.28.59 PM

Another way to tell is by looking at the prop visually. This diagram represents a clockwise prop. When spinning clockwise, the leading edge should always be in the front.

 

Screen Shot 2014-02-13 at 10.29.07 PM

This next diagram shows a counterclockwise prop spinning clockwise. As you can see, it will generate a little bit of negative lift if spinning clockwise.