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3. Computer Aided design

This week I learned some new softwares fo CAD and drawing and created some sketches. Moreover, I created a 3D CAD skecth of a mobileplatform that will be used in my final project.

The goal of an assignment this week was

  • model (raster, vector, 2D, 3D, render, animate, simulate, …) a possible final project, and post it on your class page

Then I planned to model part of my final project in 3D. As long as 2D modeling would not be related to my final project, I tried to draw my favorite character “SNOOPY” by using some kinds of drwaing sosftware.

2D design

I tried 3 kinds of drawing software, Inkscape, FreeCAD, and GIMP. By using these softwares, I drew “SNOOPY” to prepare for an assignment of next week.

Inkscape

The shape of “SNOOPY” has a lot of curve lines, so to represent this kinds of lines, I used *** function.
This function enabled me to draw complex curve lines very easily. And even if I fail to correct curve lines, modifying them is easy as well.
After finishing drawing outward form of “SNOOPY”, I realized I sould have erased extra lines shown in below figure.

To erase the extra lines, I learned below steps from local instructor. - Select 2 points existing on both sides of a target node - Separate the target node from the path by selected points - Erase the target node

After erasing extra lines, I completed my desired design in Inkscape. “snoopy”

FreeCAD

By using FreeCAD, I also drew the same “SNOOPY” as Inkscape. FreeCAD has also has usuful function to draw complex curve lines, so I could also draw similar shaped lines. Completed design and interim progress design for FreeCAD are shown below.

GIMP

GIMP is one of the raster drawing softwares. In my impression from trying these software, using GIMP was the most comfortable for me. After setting paths, I could choose a lot of lines to draw along the paths, so I think GIMP would enable me to draw many kinds of sophisticated pictures.

3D design

I used Fusino360 to design a hardware of my final project, because the CAD software has a lot of powerful function, although it is free for 3 years.
Moreover, there are a lot of guidebooks of Fusion360 and I have been studying fusion360 sicne the last December by reading some books. I have already read the following books (Japanese). - Beginner
- Advance
- Super Advance

Designing the mobileplatform of mu finalproject

As I described in page of week1 assignment , I am planning to build a robot that includes a manipulator and a mobileplatform.
In this week, I desgined and created a draft 3D CAD data for the mobileplatform.
Rough sketches of the mobielplatform are shown in following pictures. As these pictures show, the mobileplatform will be built based on two flat bases. Moreover, distance sensors,ultar sonic sensors, will be attached at four lateral directions.
“Pictures of skecthes”

After finishing rough skecthes, I started to create a 3D model of the mobielplatform.
- Base model

Base model is a very simple shape.

  • Side copmponent

Side component is necessary to assemble two bases (top and bottom) and to attach ultrasonic sensors. As following figure shows, the side component has two small holes for a ultra sonic sensor to be equipped without any screws or glues.

To create ths side component, information of hardware size of the ultra sonic sensor was necessary. Then, to obtain the information, I got 3D CAD data of the ultra sonic sensor from GrabCAD website. The type of ultra sonic sennsor will be HC-SR4, because I have a lot of experiences of using this sensor. I downloaded a 3D CAD data of this sensor from Downloadlink

After designing a side component, I imported the downloaded 3D data into my working CAD data.
To attach the distance senosr rigidly at the side component without any screws or glues, the small holes were needed to create by appropriate size.
To achive this, I used a function of

Finally the assembled mobileplatform is shown as following.

The 2D and 3D models can be downloaded from

2D model

3D model

  • Downloadlink of GrabCAD
    Note: The file(f3d) size of my 3D model is more than 10MB, so I could not upload it on my git and skecthfab.