3D printing practice

1. My 3D printing

In my practice ,I use EBU 3D printer

We build a Aluminum profiles structure to support different kinds of material and it is easy to change material.

2. Slice software

I use Cura to slice model.

When we have a 3D model and are ready to print, we need a program that prepares your file for your 3D printer. A slicing program takes an STL or OBJ file and creates G-code, the code that instructs your 3D printer where to move the print head to, how fast to move it, and what path to follow. Cura is Ultimaker’s slicing software.(reference from cura)

2.1Choice the model

Click the button(Open file) and choice the model we need to print
Also we can use mouse to put the stl format into the Cura
Normal we would use STL,OBJ format ,and some time will use AMF for speical requirment

STL and AMF format

2.2 Locate the model the model

I use move ,scale to locate the model

We must make sure the model in the software is yellow, or it would has problem.

2.3 3D printer parameter Setting

Quality(Layer height:0.1mm ),it is one of the most often changed settings. It means the thickness of one printed layer (in mm). With a thinner layer height you will usually increase the quality of the print, leading to a smoother surface and more detail visible in the Z-direction (height) of the model. On the other hand, by using thicker layers you can decrease the print time substantially.

Shell(wall thickness0.8mm, top thickness1.6mm, bottom thickness 1.6mm).Wall Thickness adjusts the thickness of outside walls (on the X/Y axis) of the model.It is generally a multiple of the line width(in our machine is 0.4mm). In general a wall thickness of 2 or 3 times the line width is sufficient.
Infill(5%infill density)—Settings related to the inside of the print. Infill density defines the amount of plastic used on the inside of the print. A higher infill density means that there’s more plastic on the inside of your print, leading to a stronger object. An infill density between 10% and 20% will be enough for most objects though.
Material(temperature is 200,and Diameter i 3mm)—Settings related to Material. It depend on material. Normal vendor will give us the reference parameter.And we need to test it.In our test ,the temperature is 200, and Diameter is 3mm
Speed(Infill speed(60)mWall speed(30),Top/bottom speed(20))—Speeds at which the print head moves while printing. A higher print speed will lead to a shorter print time and the effect would a little worse
Cooling(yes)—Settings that define how the plastic is cooled. I enable the print head fans during printing because cooling will increase the print quality.
Support(yes)—Options for support structures. Because my models have overhanging parts,I use a support structure under the model to prevent the plastic from falling down
Platform adhesion(Brim)—Options for how your model relates to the build plate. Options include Brim, Raft, and Skirt.

3. 3D printer :

3.1 Load material

Load material according to the below picture.I need push the material into the inlet of machine.

3.2 Check the platform

Rotate the bolt under the platform to change the heigh of platform.

I use paper to check it. It is OK if there is resist during moving the paper.

3.3 Operation the machine

Open the main power of machine
Use switch to choicePrint from SD-3D body
Wait for printing;
After finish ,take it away from platform slowly

4. Design guide

I use the following cases to show some basic design guide

4.1 Support angle

I use the test support model to test the performance of 3D printer.

There is no doubt that support in 3D printer model will influence the detail of the surface and we need tool to polish it(sandpaper, knife,Water outlet pliers, file ,etc)

This model can make sure which angle need to support,and the right picture show the test result of the machine performance in the point of support. If the degree bigger than 45, we'd better add support.

4.2 Bridge

If the bridge is too bigger ,the bottom of the model would drop down because of gravity, so we need to control the distance . If the distance must be big ,we need to add support to make sure the bottom.

4.3 Connection

the rotation of robot after printing

If we want to make rotation part together, we need to make sure the gap between hole and axis, in this case we need to leave about 1mm(this model is from thingiverse)

4.4 Output data

Chord heigh as small as possible

the explian of chord heigh

Most CAD software will let we choose a parameter called chord height or tolerance. The chord height is the maximum distance from the surface of the original design and the STL mesh. If we choose the right tolerance, our prints will look smooth and not pixelated. It’s quite obvious that the smaller the chord height, the more accurately the facets represent the actual surface of the model.

5 The advantage of 3D printing

In this part, I design and 3D print an object that could not be made subtractively and compare them. I find the direction of Cooling waterway.In industry it has requirment in cool and seal.[Reference from this link]（https://www.koln3d-tech.com/service-moldmanf.html）

I design a demo and attach link for review

There is a empty pipe inside and can't be made by subtracticely. So I choice 3D printing technology. The following is the effect of the demo. I inject water in one end and the water would running out to another hole.