Arcus 3D C1 Cable 3D Printer by Daren Schwenke

thingiverse

To make it easier, let's render some pieces to do that. The project isn't mine; it belongs to Daren Schwenke. Check out the information on Hackaday for more details. https://hackaday.io/project/26938-arcus-3d-c1-cable-3d-printer https://github.com/Arcus-3d/C1-Hardware This project aims to be a very low-cost portable 3D printer with a scalable build diameter and reasonable accuracy. The design, as rendered in OpenSCAD source, can scale from about 200mm to 600mm build diameter using the same parts by adjusting the length of connecting rods. The build height is approximately equal to the build diameter. The printer can also be "flat packed" for transport by removing the vertical rods; the system tension holds them firmly in place. Hardware and software are working as designed now. The current focus is on dialing in the tripod kinematics and homing settings, then generating a methodology for others to use to do the same. Origin I wanted to create a simple, low-cost 3D printer using available parts from other projects, so the C1 was born. Designed it in my head, then modeled the parts in OpenSCAD. All I didn't have on-hand were the rods (driveway markers and a garden stake), which cost me $12. I started independently on this path but then a forum post pointed me to the Flying Skydelta. Awww... It's a lot like that, with cheaper hardware. System Overview An octahedral equal length frame made from low-cost fiberglass driveway markers supports 3D printed corners. The vertical components of the frame are held firmly in place by line tension, allowing them to be removed. This facilitates flat packing of the printer for transport. Each top corner houses three pulleys sharing a shaft; cables are routed from the base-mounted spool rod and steppers through these pulleys. The relatively large distance from the pulleys to the spooling shaft results in a single layer of tightly wound cable, minimizing error from the cable spooling up to less than 0.012mm, allowing it to be ignored. The outer two cables are wrapped in the same direction and serve to position the print head using tripod kinematics; the center cable is wound in the opposite direction and routed to apply tension to a central push-rod. As the outer cables wind up, the central cable unwinds to maintain tension. A compression spring mounted on the push-rod makes up this difference and maintains tension in all lines. The required cable length is not constant; as the end effector is moved up, the required cable length becomes shorter. Virtual Pulleys Tripod kinematics without any compensation assumes end connections are points in space. They are not. Pulleys can introduce significant error into calculations: an 11mm diameter pulley can introduce up to 5mm of error into resulting positioning. This happens because as the angle to the pulley increases, the cable will wrap onto the pulley, changing the effective cable length and generating a horizontal and vertical offset. https://www.youtube.com/watch?v=v1TQYhRJY1Y https://www.youtube.com/watch?v=sj8qMLb-2Zo https://www.youtube.com/watch?v=9uQ6Beqq47A https://www.youtube.com/watch?v=S1xXMig5dao https://www.youtube.com/watch?v=KQ19fT4BQQU