Replacing quad copter receiver with an arduino

Would I be able to connect an arduino to my quadcopter flight controller instead of the RC receiver in order to control the quadcopter and if so how? I only need to be able to control motor speed.

Would I be able to connect an arduino to my quadcopter flight controller instead of the RC receiver

Yes, but why?

I only need to be able to control motor speed.

Using the proper hardware is usually better than substituting something less efficient.

I agree with Paul. There are several arduino based controllers out there that have already been tested and proven. But if this is rewlly what you want to do, then go for it. I will tell you that it is not as easy as it sounds. The hardware is the easy part, software is another story. If you use google, some controllere are opn source so that will get you started.

I need to be able to have to motors spin at specific constant speeds in order to take readings for a school experiment. However the throttle on the controller isnt very sensitive so i was wondering if i could connect an arduino to the quadcopter in order to control motor speed. Any pointers? would making an open source controller be the easiest way of doing this?

You have already asked this in another thread. Cross posting will get you in trouble. http://forum.arduino.cc/index.php?topic=379111.msg2614738#msg2614738

As I have stated before, there are open source controllers already out there. If you want people to contribute to your project, you would have to start it and have something working and have improved on anyone elses controller. This means that you need to learn what it takes to do this project. I would advise you to blink an LED first then go from there.