Summary

https://youtu.be/yVl75aUS3DY
https://youtu.be/ds7_uTPfOBs

Automatic string cutter. This cutter measures and cuts small sting or cord to specified lengths. it uses a pair of o-rings to drive the string off a spool and send it to the guillotine. the guillotine has a stack of quarters to provide the cutting force. In future versions i will try to reduce the additional required parts and hardware.

Prints -

Print 1 of everything .3 resolution is ok
print 2x spool holder pieces if using.

Other required parts

-2 nema 17 motors

• 2 or 3 axis arduino control board
• 12v power supply for stepper board
• 1/8" nail or steel pin
• 2x 1/8 x .5 od orings
• 1/4 od spring or smaller
• 1 m3x25 bolt
• 1 m3x14 bolt
• 10x m3x8 bolts countersunk
• 2x m3 set screws
• 2x 3x8 bearings
• 1 to 10 quarters
• razor blade

spool holder uses 3x 3/8 x 16 all thread

Minimum Arduino code

#include <Arduino.h>
#include "BasicStepperDriver.h"

BasicStepperDriver stepper_feed(200, 2, 5, 8);
BasicStepperDriver stepper_cut(200, 3, 6, 8);

void setup() {
stepper_feed.begin(200, 1);
stepper_cut.begin(200, 1);

stepper_feed.enable();stepper_cut.enable();

}

void loop() {

stepper_cut.setRPM(100);
stepper_cut.rotate(200);
stepper_cut.setRPM(300);
stepper_feed.rotate(-2000);//distance of string
stepper_cut.rotate(-200);
delay(500);
}