depre:
I am currently running with IRFZ44N's to power 4 DC motors for a quadcopter. I am sending a 50% duty cycle wave from D6 and this is what i read on the oscilloscope:
(I am sorry for the shit quality, however you can see 40mV as the voltage).I am using the AnalogWrite(6, 128); command to test a 50% duty cycle on pin 6. My motor turns however barely any of the power source makes it through so little to no power reaches the motor. I have 2 small 3.7V lipo batteries with 330mAH each powering the quadcopter.
The frequency is 490Hz which i believe is the default. (if I'm wrong its whatever the default is).
Its worth noting I was expecting square waves when viewing the output on an oscilloscope, not sure why this is happening. The circuit diagram for each motor I am following is this:
(however I am using a Nano instead of an Uno which shouldn't make a difference)This is only a fun project
First thing I notice is: 60V -- also, is that plus AND minus 60V, or just +60V and 0V? Either way, it exceeds the MAX VDSS of the MOSFET (which is rated at 55V).
Looking at the photo of your scope, I see a period of 128.0µS and a frequency of 7.8231kHz (which is close to the inverse of 128µS), so either this is some sort of unrelated noise, or the PWM frequency is more like 7.8kHz.
If you disconnect everything from the Arduino pin, what does the waveform look like (on that pin) -- is it nice and square?
That waveform looks like inductance, which is odd. I wonder if your MOSFET is shorted from Gate to Source (I'm not sure how a MOSFET fails when it is hit with more voltage than it can handle across it's Drain to Source channel (when it's turned off) but maybe the Gate to Source shorts out 
)
BTW: even at 7.8kHz, the Arduino output should have no problem driving a MOSFET like this. You just, probably, need one that will take the voltages in use. Also, I would not really consider this a Logic Level MOSFET (at least, not for this application). But, we still don't really know the current demands on that motor -- though, unless this is a really big quadcopter, it's probably well within the drive capability of this class of MOSFET. Also, 60V on a quadcopter? Maybe this IS a really big dude!?!
And, yet another also... you probably want to choose a MOSFET that is small and light. There are such things that can handle a LOT of current -- but, they are usually SMD.
And, also yet again, consider something like a Pro Mini or a Trinket for your quadcopter -- weight reduction being an issue, I would think?!