in

3D Printer Design Guidelines

Structure Of 3D Printer

As you are keen to learn 3d printer design today, I myself, a few years ago has the same curiosity and motivation. In this article, I will completely cover 3d printer design parameters and 3d printer manufacturing guidelines. 3d printer consists of 4 parts:

  1. Cartesian robots to move in 3 dimensions
  2. Thermoplastic extruder to melt the plastic for printing
  3. Print-bed designed for high adhesion and better heat consumption
  4. Endstops ( a switch) that limits the movement of axis up to a specific point

As 3d printer has become one of the most loved machinery in manufacturing and material departments, its demand is also increasing day by day. Apart from industry and other manufacturing departments, Students and other science-related professionals are also interested to learn about this. The 3d printing revolution is now. Increasingly reasonable, packed with possibilities and comprehensible, 3d printer still produces challenges to new users. Even you owe your own 3d printer, you have to know about the design of 3d printer to make certain changes according to your project. The applications of 3d printers have become so vast that nowadays, it is used in human anatomy and pathology also. To learn more about this, Click Here

Working Principle

In 3d printing machine, as we make 3d objects by melting ferromagnetic material and then spread the melted plastic in a 3-dimensional pattern and then cooling the melted material in printed form. So in order to create our project, we take the following steps. First, we have to first melt the material using a thermoplastic extruder which has thermal core inside it. Now in order to print the material, we need a 3-dimensional co-ordinates axis to spread the material on the Print bed. Furthermore, we have to limit the axis so that the material to be printed does not go out of bound using endstops (Limiter Switch). We will look at each part in detail below:

 

Cartesian Robot

            As the name shows that it’s a 3-dimensional printer that is used to make a three-dimensional object from a digital file. The working of 3d printer is based on additive manufacturing which is a process of making objects by laying down the successive layers of materials until the object is created. Thus, such a process helps us in building complex 3-dimensional shapes. So, in order to produce 3-dimensional shapes and materials, we have to design the axis in such a way that it moves in all 3 dimensions. So Cartesian Robot is the main idea of 3d printer design. As the co-ordinate system has three axes that can move in 3 directions (x-axis, y-axis, and z-axis). Similarly, this is a machine that can move linearly in 3 dimensions (x-axis, y-axis, and z-axis). To move the axis linearly in each direction, we make use of stepper motors. To learn more about the stepper motor, click here. Steppers motors are usually used for greater efficiency and small steps. Almost with a 1.8-degree rotation of stepper motor, axis moves almost 1mm which is a great step towards its efficiency. The more accurate the stepper motor is the more resolution the stepper motor has and the more likely the 3d printer is more beneficial and helpful to you and your projects. The complete schematics of the 3d printer co-ordinate robot is shown below:

As we have co-ordinate robots to move in all three dimensions, now we have an easy way to make any 3-dimensional objects layer by layer (additive manufacturing) and by increasing the efficiency of the stepper motor (Which decides how much shortest step we can take), we can increase the resolution of 3d printer (The shorter the step of 3d printer, the greater is the resolution of the device and hence the more accurate the object we made). Thus, in purchasing any 3d printer, you have to give special attention to the resolution of the 3d printer.

Thermoplastic Extruder

Now we move to one of the most critical and important part of this 3d printer design which is a thermoplastic extruder. Early, we learn the axis motion of the machine. Now let’s dive into the melting of thermoplastic material which is done by thermoplastic extruder. In this topic, we will cover the detail of material use for printing, the heating mechanism of extruder and also the structure of extruder. The complete schematics of thermoplastic extruder is shown in Figure below.

First of all, we shall know what is an extruder. It is a part that is capable of laying down thin strands of thermoplastic. Extruder converts the plastic into a semiliquid state for printing using heat.

Extruder has two parts which are given below:

  1. The Filament drives
  2. The Thermal Hot end

Now first covers the filament drive. It is a part of extruding where thermoplastic material enters the extruder. The nozzle where extruding material enters the machine has different sizes depends on the size of material (Usually extruder has a nozzle of 1.75mm to 3mm) and thermoplastic material is usually available in the form of threads. So, we enter the thermoplastic materials in the form of threads to the extruding device.  The thread enters an extruder usually through geared drive mechanism or through the use of stepper motors as I have already discussed.

After we move the thermoplastic into the extruder, the next step is to melt the material. It is where the role of the thermal hot end comes in. This part is made to heat the material and melt them so that it can be molded into any material you want using the co-ordinates robot’s mechanism as we have described earlier. The thermal hot end is usually made up of a large block of aluminum with an embedded heater or some other heating core. Usually, the temperature of the heating core is settled between 170℃ to 220℃ depends on the thermoplastic you want to melt. Now you have melted the material, the next step is to move the material through a nozzle attached to co-ordinates which is usually 0.35mm wide. The size of the nozzle also plays an important role in the resolution and timings of objects. The smaller the size of the nozzle, the thinner layers of melted thermoplastic come out and more resolution of 3d printer occurs but there is a cost of time. So while purchasing we have to prefer one of these parameters depends on our needs. To learn more about Chemical synthesis in 3d printer, Click Here”

https://ya-webdesign.com

As we have seen the extruder in detail, now let’s have a little look at the thermoplastic we should use in our projects. We will see different kinds of thermoplastic material and their pros and cons in this paragraph. Thermoplastic is available in different diameters, length or spools. Two types of plastic are very common these days.

  1. PLA or Polylactic acid
  2. ABS or Acrylonitrile butadiene

ABS or Acrylonitrile butadiene has many significant features as it is durable, flexible and has many much features for easy molding of material but it has one problem as if we use this material, we have to set the temperature of print bed (As discussed later in article) up to 110℃ otherwise cracking of printed material can take place.

Polylactic acid or PLA has gained significant importance in this era due to its availability and useful features. It is also much durable and flexible and we have to adjust the temperature of print bed only up to 60℃ for better molding without cracking. Thus, it has become more user friendly nowadays.  

https://www.flickr.com/photos/[email protected]/15760663749/in/photostream/

Print Bed

Print bed is a surface where your design prints. We have to take care of certain parameters in mind while thinking about print bed

  1. Size of print bed which should be according to our projects
  2. Material of print bed which interacts efficiently with our thermoplastic

The size of the print bed varies from one printer to another. While you are purchasing your 3d printer, you must consider the size of the print bed depends on the size of the project you want to make. So, the size of the print bed must be large enough to meet the needs of your project. The size of the print bed ranges from 100  to 200. Also, the difference of print bed height from axis also matters as if the height of your project is larger than as your printer provides, you must think of another option for the purpose.

Fig. from Panucatt.com

Secondly, the material we use in the manufacturing of print bed also matters a lot as it prevents the wrapping and cracking of printed material by better adhesion and heat transfer. So in order to meet this situation, we should take care of print bed material also. So, the print bed is mostly made from glass or aluminum. The surfaces are made from either glass or aluminum depends on the different situations as glass provides the smoothest surface and aluminum provides better heat conduction. To learn more about 3d printer bed parameters and properties, Click Here

ENDSTOPS

End stops are basically the switches which are used to limit the axis rotation of co-ordinate robots in any axis. We have to limit the switches depends upon the size of the print bed. If we do not limit the axes, the material will go out of print bed and it will be wasted. So, we have to limit the rotation of each of the axis. As every axis moves linearly, their limitation of the axis is an important part of 3d printer design and 3d printer manufacturing. So in order to control the switches, we control the number of rotations of the stepper motor. As we have mentioned above that with 1.8-degree rotation in the stepper motor causes 1mm movement in any axis. So limiting the number of rotations of the stepper motor by using a counter switch, we can control the bound of each axis. This can be better illustrated by an example. As with 1.8-degree rotation, each axis moves 1mm. In one complete rotation of the stepper motor, there are 360 degrees and each axis will move  = 200 mm. Thus controlling the number of rotations, we can control the movement in each axis.

What do you think?

Written by Ghost

One Comment

Leave a Reply

    Leave a Reply

    Your email address will not be published. Required fields are marked *

    An Introduction to NUMPY: Numerical Python for Computation