1. Objectives

In this assignment, I have designed a robotic arm and then 3D print some of theparts that culd not be made subtractively. Moreover I tried a iSense 3D scanner.

2. Introduction to 3D Printing

Fig 1.0.1 : What is addictive manufacture? Resource: 3d hubs

Additive Manufacturing is know by many names: 3D Printing, Rapid Prototyping, Rapid Tooling, Rapid Technologies, Rapid Manufacturing, Advanced Manufacturing, additive Fabrication, Additive Layer Manufacturing, Direct Digital Manufacturing and Direct Manufacturing. Today additive manufacturing focuses on features such as geometric freedom and speed is not he sole determining factor.

Unlike most conventional manufacturing techniques, Additive manufacturing forms oject bz building matter up, rather than removing it.

Additive manufacturing technologies are use to manufacture: Prototypes, tools and production parts.

2.1 Advantages of AM in Production

Potentials

Increased geometric freendom : under cuts, function integration and new deisgn possiblities

Production of individual parts (mass customization)

Spare part production "on demand"

Parallel production of different parts

Constant effort for set-up

Low maintenance costs

Tool free or non wearing operation

Reduction of storage costs and capital tie-up costs

2.2 Disadvantages of AM in Production

Potentials

Restrictions regarding wall thicknesses , hole diameteres and clearances

High surface roughness in raw state

Support structures necessary

Slow manufacturing process

High energy costs

Material selection is limited

(up to now) not suitable for mass production

parts qulities difficult to quantify

3.0 Principle of 3D printing (3DP)

3.1 How it works

A wire shaped material is melted in a high temperature nozzle

Plotter mechanism

Hard lazers of plastic or metal filaments can be created

3.2 Pro

Low cost

Multiple jetting possible

3.3 Con

Slow process

Inconsistent material due to construction in layers

Machine suppliers: Most common technology for desktop 3d printing.

4.0 Data exchange file formats for AM

This is a very common way to save your 3D CAD model and there are some charteristics and what can be wrong with this alogorithm.

LMI, VERML, CS, RPI and STL,etc

STL - orifinally STeroLithograpy, today Surface Tessellation Language also known as Standard Triangulation Language

4.1 Characterisitcs of STL

Neutral data format

Developed in 1987 for 3D Systems

Orifinally developed for stereolithography applicatrions

Easy Mathematical description of the faceted surface

Simple slicing algorithm (operations on traigles)

Ability to splot models

Wide range of input ( nearlz all 3D representations acceptable

Not officially standradized

Widespread use

4.2 Quality issues due to Tessellation

After tessellation following erros can occur:

1. Wrong proemtation of triangles

2. Wrong contour

3. Missing triangles

4. Intersecting triangles

5. Too fine/coarse triangulated

5.0 Supports

Supports are used when models have sttep ovehangs or unsupported area

A general rule of thumb is that most printes can support ovehang angles less than 45 degrees

6.0 Robotic Arm

6.1 Sketch Idea

First of all I sketeched my idea what I am going to 3D model and some of the feutures of the robotic arm.

6.2 Part List

I am planning to use a 3d print and laser cut a plywood to fabricate the robotic arm.

Part list:

Arduino Uno

Cables

M3 nuts and screws

3x Servo MG996R

3 mm and 6 mm thickness plywood

PLA

6.3 3D CAD

3D CAD of the robotic arm that I am going to build.

6.3.1 Head

To model this is simple you have to design so that it can hold the servo motor and assembly this to another part.The feuture I used to model this head part is boss extrude, mirror, filet and cut extrude.

6.3.2 Shoulder Join

As you could see this object cannot be produced because the inside of the part should be cut and a CNC milling machine head tool might be to large to cut this.

6.4 2D Drawing

After I have modeled the 3D CAD using solidworks, I made a new 2d drawing and put all the parts that I want to laser cut.

6.5 3D Print

6.5.1 Cura

Cura is the software to generate the g-code of a 3d printer and set the properties.

6.5.2 Printing properties

It is time to print two parts of the robotic arm, the head and he shoulder join and I was printing with Ulimaker 2+. Printing PLA is quite easy because it melts in a low

Ultimaker 2+

Print setup: Custom

Material:PLA

Nozzle : 0.6 mm

Layer height : 0.25 make sure that the layer height is less than the nozzle size and this will effect the surface roughness of the product

Wall thickness: 1mm

Top/ Bottom thickness : 1mm

Infill density 15 % depends how strong you want the material and the printing time is.

Enable reaction is to checked to make sure there is no extrusion when nozzle moves from one point to another.

Print speed : 60 mm/s how fast to print

Travel speed : 120 mm/s

Enable cooling

Gernerate support

Support patern Zig Zag

Support distance = 5

Start to print and it takes arround 3 hours to print.

Remove the support from the material

6.6 Assembly

Assembly the 3d parts to the plywoods with m3 screws.

Finally we have a robotic arm!

7.0 3D Scan

7.1 A Chair

The assigment is to 3D scan an object.

The 3D scanner that I use in our FabLab is called iSense which is attached to an Ipad.

This is my first experience using a 3d scanner and the result is not that bad.

We will have to rotate 360 degree and move up and down to scan the object.

The result for shaded View.

The result for x-Ray.

The result for colour view.

This is the overall view of my first experience of using a 3d scanner.

7.2 My dad

The harware I used to 3D Scan was actually my Iphone x with ScandyPro software in IOS.

Then I tried to 3D print it and the following picture was the result

8. References

Cura

iSense

9. Download

Robotic Arm 3D CAD

3d Scanner file