Straighten a Bent Main Shaft

It’s a norm for pilots to bend its rc heli’s main shaft, especially beginners. And a bent main shaft usually leads to number of problems and affect the flight performance seriously.

What could be happened with a bent main shaft?

Symptoms
1. Wobbling Head
2. Decrease in power
3. Increased difficulty in hovering
These are possible consequences of a bent shaft, you can verify if it’s bent simply by observe its motor head movement or roll it on a flat surface. Most people get used to buy a new shaft,but it would cost you much in long term, so why don’t fix it in a money saving way?

How to straighten main shaft?

There are number of ways to straighten a bent main shaft. Some use dial indicator, lathe, hammer or a drill chuck to cope with the problem.

Marker/Pen Trick

If your shaft is not multi-bend, this video tutorial by using a marker helps. After marking the position to be bent with pen, use a pair of pliers to bend the shaft towards the direction without red line on it.

Drill into Wood

Here’s an alternative method to fix the bent shaft, sounds unbelievably simple! But seems only for Blade CP Pro, maybe work for other remote control helicopter as well.

1. Drill a hole, which fits the diameter of bent shaft, in a wooden block
2. Put main shaft in drill and through hole
3. Spin up and pull the drill to the side bending the shaft- as it spins pull it out slowly and gently on the shaft
4. As you pull it out it will straighten the bend at the same time
5. Flip main shaft and repeat several times as necessary until shaft is straight

Shaft Straightening Tool

This kit looks insanely effective on main shaft repairing, though it’s only for CP/CP2.

I’ve googled for a while, but still can’t find where can I buy this tools. If you know where can I buy it, please let me know!
One last thing to remember: When you bend a crank you may damage the gears, so be careful.