Cetus 3D Extruder

thingiverse

I was frustrated by the original Cetus3D extruder design. I had to take it apart to ensure the filament was feeding properly. This design allows adjustable filament feed tension, quick release of the filament and an open design to allow viewing the filament during printing. The spring has a 3:1 advantage over the pressure bearing. It has been tested to print with PLA and PC-MAX, but has not been tested with other filament types such as ABS or flexible filaments. The screws and spring can be purchased from ACE Hardware or Amazon. The bearing can be obtained on Amazon. Please provide feedback and suggestions for improvement. Four pieces are required to be printed: 1. A new extruder PCB enclosure that moves the mounting from the face of the extruder motor to the holes on the top. Use the screws that were used to secure the board to the top of the NEMA motor. 2. A spacer attached by two screws to the face of the extruder motor. This provides a smooth surface for the lever arm to rotate against. It is advised to smooth the surface facing outward. I printed this in Polymaker PC-MAX. 3. An open filament guide with spring holder. A screw can be threaded into the downward facing hole and a small 3mm screw and washer inserted below the spring. The screw provides tension adjustment. I printed this in Polymaker PC-MAX. 4. A lever arm to hold the pressure bearing and provide quick release. Install the lever arm loosely before installing the spring. I printed this in Polymaker PC-MAX. Other parts required: Bearing (3x7x3 mm Miniature Steel Bearings 683Z 618/3 683ZZ L-730ZZ) Screw to hold bearing on the lever arm (3mm x 8mm) Screw to mount the lever arm (3mm x 17mm) and two 3mm washers Screw for the spring tension adjust. Small screw and washer under the spring. Spring ~7mm x 27mm (I used a #134 spring from the local ACE Hardware) Update 9/11/18: I have found that it takes a lot of spring tension to ensure adequate filament feed. A new version of the arm is now posted that is stronger to withstand greater spring force. The filament guide piece has also been improved to better capture the filament.