Dental 3D Printing Hardware | What Are These Devices Made of?
Hardware: Backbone of Dental 3D Printing Devices
In dental 3D printing, hardware and software are the foundation for a precise, accurate, and fast printing process. The goal of dental 3D printer manufacturers has always been to develop 3D printing technology that improves the daily experience of the dentist. Typical sophisticated, state-of-the-art software suite seamlessly integrates and syncs with the hardware to provide solutions to the most common challenges associated with digital dentistry workflows. In this article, we are going to take a look at dental 3D printing software and hardware.
The Most Common Hardware for Dental 3D Printing
In general, the hardware of dental 3D printers is not much different from other printers. 3D printer hardware is divided into two parts, mechanical and electronic. In the following, we will examine the various structural parts of these devices.
Dental 3D Printing Hardware: Mechanical Parts
The mechanical parts include the print bed, bed surface, bed leveling, fiber, extruder, hot cooling element/fan, heater cartridge, thermistor/thermocouple/RTD, bed fan, motion control, stepper motor, the frame, and housing. Below we will review each item:
- Print bed: A printing substrate is a surface on which items are printed. It usually consists of a glass plate, a heating element, and some type of surface that helps the plastic adhere
- Bed surface: The surface of the bed helps the plastic adhere to the substrate during printing, but it can also be easily removed after printing is complete. There are many types of bed surfaces. Most printers have some kind of generic surface like BuildTak or PEI film. However, for the best effect, it is recommended to use a different surface depending on the printed material
- Bed leveling: Many printers have some kind of system that automatically checks whether the bed is aligned with the nozzle. However, some are not and must be adjusted manually
- Fiber: This is the plastic used by the printer. It’s on a roll. The printer uses two different-sized filaments, 1.75mm, and 3mm. There are different materials
Other Mechanical Parts
Extruder: other mechanical components of dental 3D printing hardware include the extruder which is the heart of the printer. Here the plastic is drawn in, melted, and pressed. It’s a fancy hot glue gun. Extruder consists of two parts: a hot head and a cold head. The cold end has a motor that pulls the filament in and out and the hot end is where the filament melts and breaks. The remaining mechanical parts include:
- Hot end cooling element/fan: This prevents heat transfer to the plastic and premature melting before it reaches the nozzle. This phenomenon is a called thermal creep and causes paper jams, especially with PLA. This fan should run when the hot end is hot
- Heater cartridge: The heating cartridge is obvious. As a high-power resistor, it heats the plastic. Most modern printers use cartridge heaters, but many older printers used nichrome wire coils (like a toaster). If you are replacing the heater cartridge, even the entire hot end, check if your system is running on 12V or 24V
- Thermistor/thermocouple/RTD: These are different types of sensors for determining the temperature of hot ends
- Nozzle: The nozzle is a simple element with a small hole through which the molten filament flows. The nozzles are available in different sizes. Typically 0.4mm, use a smaller nozzle for finer details and a larger nozzle for faster printing. The nozzle may also become clogged. This is one of the most common problems with 3D printers. See this article for tips on clearing clogged nozzles.
- Bed fan: This fan cools the plastic as soon as it lands on the nozzle. Helps maintain the shape of objects. The Slicer turns this fan on or off in different conditions, depending on the material being printed. Not to be confused with a heatsink fan that cools the hot end itself, not the printed matter.
Motion Control – X, Y, Z Axis
A Cartesian printer moves one or two motors along each of the X, Y, and Z axes and derives its name from the Cartesian coordinate system. They usually have a rectangular structural area and the printer itself is usually cubic.
The Delta printer has three arms that connect in the middle to suspend the extruder above the build area. Delta also uses a Cartesian coordinate system for movement, but instead of moving one motor per axis at a time, all three arms move at different speeds or times and triangulate to precisely move the nozzle.
Unlike the usual DC motor, which rotates continuously with power, the stepper motor rotates in increments. This gives you precise control over the position. Most printers use NEMA 17-type motor with 200 steps (steps) per revolution.
A frame holds everything together. Early presses had frames made from laser-cut plywood. Printer frames are now made of sheet metal, aluminum beams, or plastic. Many parts of the frame are often 3D printed themselves. The stiffer the frame, the more precise the printer’s movements.
Dental 3D Printing Hardware: Electrical Components
It takes 120V AC power from the wall and converts it to low-voltage DC for use with the printer. The ATX power supplies are the same power supplies used in desktop computers. They are reused for use in many printers. They are very thick and powerful and have separate wires that power them with different voltages (12V, 5V, 3.3V). Some machines use 12-volt systems, others use 24-volt systems. This is very important when replacing components, especially heater cartridges or hot ends.
The motherboard is the brain of the printer. It takes commands given to it (in the form of G-code) from the computer and arranges them to be executed. The motherboard contains a microcontroller (essentially a small self-contained computer) and all the circuitry needed to run the motors, read the sensors, and communicate with the computer.
These chips are responsible for running the stepper motors. They trigger the coils of the motor in sequence, stepping them into motion. Many motherboards have stepper drivers built in, but some motherboards have them built into removable modules.
By balancing the power delivered to each coil, the driver can also split steps into additional steps. This is called micro-stepping and allows you to control the motors more precisely than usual. The step controller also controls the amount of current supplied to the motor. More power makes the engine more powerful, but it also heats up.
Dental Needs: Driver of 3D Printing Hardware
Here we covered some of the most important dental 3D printing software. The rapidly changing environment of dentistry creates unique challenges that require continuous skill development. This is why the software exists and will continue to evolve in the coming years.