Week 2

Computer aided design

2D - AutoCAD

Design File (dwg) and .dxf

I chose to use AutoCAD as my 2D design software. The logic was that this software is Industry standard to architectural drawings. My final project is on Water Management, and being able to understand and use this software package will be good for me.

Approach to learning this package

I have listed below the most basic commands I need to know to design my solution in 2D and made .gif images of how I did it so that anyone can replicate it. There are 3 simple videos on the interface of the software, which on first looks can be very intimidating.

Video - introduction to the command prompt and help screen
Video - 2 methods of selecting objects in AutoCAD
Video - drawing different shapes. and measuring dimensions

Assignment - drawing a component (box for server) of my final project in 2D

  1. Measure the Raspberry Pi - and make a rectangle for the size of it as shown here. This will help me understand what is the basic size of the object I'm dealing with. Click to view a .gif file showing this process.
    Commands used - "l" for line and "pl" for polyline
  2. Create a new layer, offset and create a new box, copy box and label as shown below. Click to view a .gif file showing this process.
    Commands used - "copytolayer" for copying to another layer, "offset" to create an offset object, "co" to copy the object and "text" to label the objects
  3. Draw 2 more boxes for sides. Commands used are same as above. Click to view a .gif file showing this process.
    Commands used - "dimension" for putting out dimensions of the object
  4. Polyline doesn't allow individual lines to be offset. Hence redrawing the boxes as individual lines. Click to view a .gif file showing this process.
  5. Post that, complete the box using the above commands. Click to view a .gif file showing this process.
  6. I was able to lasercut out a rough mdf box for the server using this drawing which had errors, as I hadn't accounted for material thickness.
  7. I made the final version of the box, with cutouts for lips in the other pieces which could fit inside using the move command, which helped align all the components as shown below. Click to view a .gif file showing this process.
    "mov" brings up the move command which allows you to shift and align objects
  8. The laser cut version looks like this, click on the image to see a video of the box

3D- Fusion 360

I had 2 options for this - Rhino5 or AutoDesk Fusion 360. With no context to design till now, I read some sites like . I have tried Rhino out and personally find it easy to use. In this case, I took the chance to work with Fusion360 for these reasons

  • Since its an AutoDesk product, most of the keyboard layout as AutoCAD is same.
  • I decided to go with AutoDesk FUSION360 as AutoCAD is an industry standard, and allows me to integrate my devices and placement at the stage were the drawing of a building is being discussed.
  • I have not tried parametric design with Fusion360 so far. The software allows for defining variable names and allocating measurements to it before we start drawing. This makes design modification very easy and intuitive.
I decided to try making a more complex design with the Fusion3D. I decided to make a 5cm box, with a threaded hole in the centre, with a cut out in such a way that you can see the threads partially.

commands -
"rectangle" for a rectange
"extrude" for extruding it into z axis
"hole" to make a hole from the centre "thread" under Create menu to make the thread, select the options shown in the next screenshot
"l" for line, to draw from one corner of the base to another
"Sweep" to do the cut as shown in the final image

I made the first file like this, but it came out with errors, the thread was not printed as shown in the image below. The output was to match the gif image below the image of the error. Click on image to see a .gif


Conclusion

For 2D drawing, I decided to go with AutoCAD as its industry standard, and allows me to integrate my devices and placement at the stage where the drawing of a building is being discussed. The vision is to make this the building block of a smart city. For 3D, I decided to go with either Fusion 360 due to its similarity with AutoCAD or with Rhino, which for some reason felt easier.