Print head for additive manufacturing system
A system is disclosed for additively manufacturing a composite structure. The system may include a support, and a print head operatively connected to and moveable by the support. The print head may include a supply of continuous reinforcement, an outlet configured to discharge the continuous reinforcement, and a tensioning module disposed between the supply and outlet. The tensioning module may be configured to generate a signal indicative of a tension in the continuous reinforcement. The system may also include a processor programmed to selectively cause the supply to dispense the continuous reinforcement based on the signal.
1. An additive manufacturing system, comprising:
a support;
a print head operatively connected to and moveable by the support, the print head including:
a supply capable of supplying a continuous reinforcement;
an outlet configured to discharge the continuous reinforcement;
a tensioning module disposed between the supply and outlet,
wherein the tensioning module includes:
a swing arm configured to pivot depending on a tension of the continuous reinforcement;
a first redirect located at a first end of the swing arm, wherein the first redirect is configured to receive the continuous reinforcement;
a second redirect located at a second end of the swing arm, wherein the second end is located upstream of the first redirect relative to a travel of the continuous reinforcement through the print head and wherein the second redirect is configured to receive the continuous reinforcement;
a pivot located on the swing arm coincident with the second redirect, wherein the swing arm is configured to pivot about the pivot;
a rotary sensor associated with the second redirect, wherein the rotary sensor is configured to generate a signal based on the pivoting of the swing arm about the pivot; and
a counterweight mounted to the second end of the swing arm, wherein the counter weight is configured to at least partially balance the swing arm about the pivot;
and
a processor programmed to selectively cause the supply to dispense the continuous reinforcement based on the signal generated by the rotary sensor.
2. The additive manufacturing system of claim 1 , further including a wetting module configured to wet the continuous reinforcement with a matrix prior to discharge from the outlet, wherein the tensioning module is located between the supply and the wetting module.
3. The additive manufacturing system of claim 1 , wherein at least one of the first redirect or the second redirect is rotationally mounted to the swing arm.
4. The additive manufacturing system of claim 1 , further including a spring at the second end of the spring arm and configured to bias the swing arm.
5. The additive manufacturing system of claim 1 , further including an end stop located at a first side of the swing arm and configured to limit a position of the swing arm.
6. The additive manufacturing system of claim 5 , further including a biased end stop located at a second side of the swing arm and configured to limit another position of the swing arm.
7. The additive manufacturing system of claim 1 , further including a biased end stop located at a first side of the swing arm and configured to limit a position of the swing arm.
8. The additive manufacturing system of claim 1 , further including a spring configured to bias the swing arm.
9. The additive manufacturing system of claim 1 , wherein the rotary sensor is one of an encoder and a potentiometer.
10. The additive manufacturing system of claim 1 , wherein the tensioning module is configured to apply a tension of no more than 5 lbs to the continuous reinforcement.
11. The additive manufacturing system of claim 10 , wherein the tensioning module is configured to apply a tension of no more than 1 lb to the continuous reinforcement.