After my 3D printed cigarette stuffing machine project was successful, I decided to develop a 3D printed semi automatic cigarette tamping machine. Here, my focus was to design the machine with as few parts as possible. There are a few videos on YouTube that show similar machines. However, these models are rather sloppily constructed and seem to be more of an experimental attempt at cigarette plugging. It is my assessment that most of these machines are unlikely to work effectively, as dosing the tobacco using a screw conveyor has some problematic aspects.
3D printing the components is extremely straightforward as no support structures are required. The parts were specifically designed to have predominantly flat surfaces in order to achieve a clean print result. I used PETG for the printing. It might possibly be a better idea to make the parts out of PLA, as this material is considered food safe.
The screw conveyor was wound around a round iron with a diameter of 4 mm. A copper wire with a thickness of about 1.4 mm was used for this. This allows the screw conveyor to fit precisely into a tube with an inside diameter of 7 mm to 7.2 mm. The slip-on tube I use has an outer diameter of 7.8 mm. These dimensions allow the empty cigarette tubes to be plugged on effortlessly. In addition, one end of the slip-on tube is cut at an angle to facilitate easy slip-on.
To ensure that the screw conveyor can be guided cleanly in the tube, a brass plain bearing bushing is installed. The plain bearing bushing was glued in place with super glue.
Since it is not possible to align the motor and the screw conveyor exactly without radial deviation, it is necessary to install a compensating coupling. This compensates for misalignment between the motor and the screw conveyor.
To breathe life into the machine, a motor is needed. Here I have done some tests with geared motors. It turned out that it is better when the speed is high. I used a brushless motor with 28mm diameter. For a brushless motor you need a brushless controller and a servo tester to control the speed of the motor.
The 3D files include brackets for round gearmotors with diameters of 30mm, 37mm and 40mm.
I have tested two different types of feed screws. The feed screw with a core shows the disadvantage that it grinds the tobacco into a very fine powder. This result is rather undesirable. Moreover, this type of screw has difficulty in entraining the long tobacco fibers. Constant pushing into the tobacco hopper is required. The screw with a core is more suitable for fine, dry tobacco.
To get around this disadvantage, I tried to eliminate it with my second type of feed screw. The great thing about this is that it is sufficient to simply cut off the core of the screw and then pull it out. This creates a screw without a core. Removing the core has significantly increased the efficiency of the machine. Now the feed screw can also pick up long-fibered tobacco and push it into the cigarette tube. In this way, it is now also possible to feed coarser tobacco into the tubes.
The cigarette tube holder allows the strength of the plugged cigarette to be controlled. The feed screw conveys the tobacco into the cigarette tube, pushing the tube away from the slip-on tube. The degree of resistance that the cigarette tube holder exerts on the cigarette tube directly influences the compactness of the plugged cigarette. The greater the pressure that the cigarette tube holder exerts on the tube, the tighter the cigarette will be stuffed.
You can download the building plan here:
You will get the following digital files:
- All .stl files you need to print the machine.
- .stl files for motor holder: brushless motor d=28, gear motor for d= 30mm,37mm and 40mm.
- Assembly drawing of the machine in .pdf and .dxf -format.
- The complete 3D model of the machine in .step – format.
- An instruction video with all building steps.
- I will do my best to help you with any problems or questions.