Hi, I'm new in Arduino, but I'm fascinated about all things are possible!
I'm wondering if it is possible to make a machine to cut 600m coils of 5mm strong cord into 130m cuts.
I made a machine turned by hand, but it is a very boring job to turn the spindle.
Can anybody give me an hint how I can realize that the machine stops after 130m?
The difficult part will be cutting the cord, some rendition of this might work.
A motor with a circular cutter.
Then there is these:
Thanks! That are great solutions!
But I have to get much longer length, my hand machine goes from the large coil to a smaller one.
It already would help if it stops at 130m. I could cut it by hand, I have to take the cord off the spool anyway!
The motor that advances the cord just needs to run longer to achieve the length needed.
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Is it accurate enough to count steps, or does slippage make the length too imprecise?
It’s your job in the design to keep slipping to a minimum.
More importantly, a cord will have a certain amount of give/elasticity that needs to be accounted in the design; if it’s constant, the motor control algorithm can account for this.
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How do you know you have 130m right now? How is the spindle turned today? Can you add a pulley and belt to turn the spindle? IF you can and measure the torque required, then you can size a motor to drive the belt.
A drawing of your current machine would be nice.
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left side is the large spool, right side is the measured length. Right top has a crank handle.
Discs are IKEA lazy susan. I'm willing to rebuild everything
So you will be removing the cut piece at the end of the rotation period ?
If so you only need to automate the take up reel ?
Edit.
Like your wood working skills !
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Thanks! 
Yes, I think to automate it complete is too difficult. But it helps if I can start it by hand and it stops at 130m. A difference of a few cm don't care.
The Arduino controlling a simple gear motor, a micro switch (for counting revolutions) would be quite easy to incorporate into your design.
A switch to start/stop/reset the process would be needed too.
Maybe a FWD/REV switch on the motor too ?
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Yes, nicely done. How does your measuring device work? Powering the takeup reel should be easy if you add a pulley between the lazy-susan and the plywood table. There are some quite thin "V" belts available that would work. And, of course, the same type of pulley on the motor driving the table.
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I use a counter
I used a thrust bearing, which is quite noisy. So I will build a new one anyway.
How do I measure the required torque?
How do I use micro switch for counting revolutions?
Attach a spring scale to the outer edge of the take up reel and see what force it takes to turn it with the max load from the bulk reel and counter mechanism.
Driving from the edge of the take up reel will require less torque than driving from the center with a motor mounted underneath.
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Is a stepper motor required or does any motor work?
Just thought if an extruder for a 3D printer would work to transport the cord!? It has grip, but it will be very slow I guess
A used vehicle gear window motor will have more than enough power for this project.
A small protrusion (or 4) on the take up reel would touch the micro switch as the reel rotates.
The Arduino will monitor the switch, counting the times it closes.
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I still have a 12V car window motor at the shelf, looking the same.
These are great, I using them often in projects.
FYI
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But what do you think, an extruder for a 3D printer would be too slow??
EDIT...forget it, it will be too slow...