Week 2 - computer-aided design (Feb 4)

My goal this week is to familiarise myself with a number of 2D/3D drawing tools as my previous computer drawing tools usage has been limited to PowerPoint, Visio and MS Paint.

Neil gave an overview of computer-aided design tools and different types of 2D, 2.5D and 3D tools. The assignment this week is to model the final design project using different tools.

Approach

1. Quick review of tool’s website to get look and feel
2. Download and install (if not browser based)
3. Have a go at tutorials if available
4. Reproduce Fab Lab logo in 2D and 3D to get feel of different tools
5. Choose a 3D tool to model final project concept
6. If time use other 3D tools for comparison

2D raster

Scanning

I started by using a scanner to scan the Fab Lab logo image - used black and white mode at 300 dpi, this gave a good reproduction and edge, saved as a .jpg file (164kb)

MyPaint

MyPaint requires X11 (OS X windowing system for bitmap displays), used the MyPaint OS X installer. Installed OK Window is minimalist - how do I start drawing? Read basic usage tutorial on web page and realised MyPaint is a painting programme, more suited to being driven by a stylus rather than a mouse (as you can see from my logo attempt). Controls quite slow. Drew logo using mouse, but couldn’t save it. Error trying to save file. Will investigate other tools.

GIMP

Went to gimp.org/downloads and used the Homebrew option (having installed Homebrew earlier). Installation went OK, opened it - where’s the window? Lots of tools on left & right of screen. After reading Help -> User Manual -> Main Windows, realised there is a multi window and single window mode. User Manual comprehensive

GIMP is the opposite of MyPaint with a myriad of features and options - there’s too much choice so doing a simple task can be quite challenging. The Help -> User Manual is very detailed and easy enough to follow.

My go at replicating the Fab Lab logo has been slow and clumsy. GIMP is a good tool for modifying images or removing the background for an image.

2D vector

Inkscape

Having previously installed X11 and Inkscape without problem I started to look at 2D vector drawing. The manual and tutorials are easy to follow (easier than GIMP). I followed the Quick Start guide to make a Swedish flag

David Mason demonstrated a quick way to convert an image from raster to vector. This is useful for laser cutting 2D objects. Path -> Trace Bitmap, used this method to create a Fab Lab logo ready for laser cutting.

3D

I looked at the following 3D computer-aided design tools - Antimony, Blender, FreeCAD, SketchUp and SolidWorks.

Blender

I thought Blender would be a good tool to evaluate with the ability to animate human models. I downloaded a UniHuman model but found the learning curve too steep to progress with the tool.

Antimony

After Neil’s lecture I was looking forward to trying Antimony, but found the programme to be unstable on OS X Yosemite and crashed on opening. I was unable to evaluate further as I spend a good number of hours trying to get it to work.

SketchUp

I used SketchUp about 4 years do downloaded the latest version SketchUp Make 15. While Sketchup is easy to use, I struggled to make represent my final project idea.

FreeCAD

I considered Rhino but as it is non-parametric opted to try FreeCAD as it worked on OS X, was parametric and used workbenches for different design tasks. My lack of experience with CAD packages and the lack of well documented tutorials meant learning basic tasks was painfully slow and I struggled to turn ideas into 3D models. Eventually I was able to produce a basic concept of the Footpod but haven’t been able to design the clip the way I wanted to.

SolidWorks

My understanding from other students is that SolidWorks is the gold standard for computer-aided design. It runs on Windows so I used VMWare Fusion for a Windows environment on the Mac. I was unable to complete the install process due to an error in obtaining a license from the server node. Until this is resolved I cannot evaluate.

Conclusions

What I thought would be an interesting learning experience has been frustrating and disappointing to my difficulties in learning basic 3D computer-aided design and the amount of time spent trying to get tools working.

On the plus side I was impressed by Inkscape and the ease and speed of taking a bitmap image and being able to create a vector image ready for laser cutting.

Files for download

The files from this week's assignment can be downloaded from a Dropbox folder by clicking on the following link to download.

Downloadable files

FreeCAD Footpod.FCStd
Sketchup footpod.skp