Paul_KD7HB:
There have been several forum postings in the past relating to your project. Search for them. My commercial wire measurer and cutter has one driven wheel that is knurled and has a second rubber wheel that presses the wire against the knurled wheel.
The knurled wheel is driven by a stepper motor and it is controlled by a micro-controller that measures the wire. The length is input on a key pad.
The wire cutting is done by a solenoid driven blade. The wire never stops moving. The cutter solenoid is overdriven by a charged capacitor so it moves quickly and powerfully.
Paul
I found a few, but most of them, if I didn't completely missed the right posts, was for heavier cable or not answered. I also looked at commercial products, but I'm a hobbyist and 1000€ products, isn't going to happen 
Not sure what a solenoid driven blade, but new words to Google, thx m8
It's the stripping part that worries me the most. I got 0,5mm tolerance on my cables. If I input 300mm it has to come out exactly 300mm with 3m stripped on either end.
DVDdoug:
The "trick" to any project is to take it one step at a time. And if you are new to programming, "develop" your program in very-small steps, one or two lines of code at a time, testing before you proceed. This take some practice because the program has to be "complete" and it has to make sense to the compiler... For example, if you chop-off the bottom half of a working program, it won't compile.
You might want to start with the [u]Digital Read Serial Example[/u]. Once you can read a button you can start to "do stuff". ...You could add an if-statement that turns-on an LED or runs the motor while the button is pressed, or make the stepper motor run for 100 steps every time the button is pressed, etc.
The two most important concepts in programming are conditional execution (if-statements, etc.) and loops (doing something over-and-over, usually until some condition is reached).
You can also test the motor separately. For example, write a little test program to run the motor for 100 steps. In a similar way, you can test your motor/solenoid/whatever that's going to cut the wire.
The Digital Read Serial Example, also uses the serial monitor which is one of your BEST debugging/troubleshooting tools. You can send-out little helpful messages like "Button pressed", or "Running motor". The serial monitor can also be sued to "watch" variable values (as with the Analog Read Serial Example).
This can be a bit of a trade-off. If you use a computer you can skip the buttons & display, but you'll have to write a companion computer application as well as an Arduino application. And, writing a computer (or phone) application is another "project".
Awesome help, thank you so much. Will check those examples this weekend. I bought a less qualitative starter kit (as I learned) so I miss a lot of the stuff included in many tutorials. I would like to reach the point where I ca buy the real stuff needed and learn on them. Will be cheaper in the long run, rather then first buy a new starter kit, then buy a DC motor, then buy a new Stepper motor etc.
The programming bit I'm not that worried about. I worked with web programming for many years (I know it's not the same) and very familiar with objects, passing variables, conditional statements etc...