Part 5: Winding the Extruded Filament
Winding Process
You can see in the above gif that winding includes 2 processes:
- Rotation of the spool on the spool holder
- Linear motion which guides the filament path such that the filament is not just winded in one spot but evenly distributed throughout the length of the spool
Rotation of Spool
Replace the hand crank in the above photo with a stepper motor. Look on Thingiverse there are many designs for the spool winder.
Add a potentiometer to control the motor speed, there are many guides on how to control stepper motor speed through Arduino.
Linear Motion for Filament Guide
Put a ring on the platform pass the filament through it and you’ve your filament guide ready, you can add a piece of PTFE tube for reduced friction.
It takes a stepper motor, 2 smooth rods, shaft coupler, and threaded rod. If you’ve these available build it.
But a much cheaper way is to use a RC servo motor.
Make a long 12 inch long 3d printed servo arm.
Mount it to the servo motor, pass the filament through the hole on 3d printed arm.
Now, all you’ve to do is move the arm left to right and right to left in too and fro motion like a pendulum slow enough so that the filament is wound uniformly on the spool.
This can be easily done with a 555 timer circuit and a potentiometer or an Arduino, it depends on what you prefer.
When to start winding?
Make a laser trip switch, instead of raising an alarm — this switch is supposed to stop winding (both servo arm motion and spool rotating stepper)
The laser line is placed perpendicular to the filament and parrel to ground.
When the filament puller pulls the filament through the water bath from the nozzle, the filament becomes lose between Winder and Puller which makes a U shape curve rather than a straight line of the filament.
We’ve to position the laser line such that when the filament is tight (making a straight line) between the winder and puller, it obstructs the laser path stopping the filament winder.
When the puller pulls more filament, the straight line turns into U shape curve and falls below the laser path and the winder starts again till it becomes a straight filament line and obstructs the path and winding stops, this cycle keeps on repeating.
