Sally Williams @ Fab Academy 2015

Note: At beginning of this week, I was finally able to upgrade my laptop so that I could install more applications. I am now running Mac OS 10.10 (Yosemite), so I'm now trying to get familiar with the new system, trackpad and gesture control. It has been noted that for CAD it is easier to use a mouse!

Tuned in to regional reviews to learn from others process or at least the ones that transmitted well. This was followed in the afternoon with Neil Greshenfeld's introduction to computer controlled cutting tools.

Links of interest:
XY axis CNC : http://corexy.com
Nice website on parametric design: www.parametriccamp.com/en/what-is-parametric-design

DM gave demo on simple laser cut process from Inkscape. This helped me to see the workflow required from vector to pdf to lasermachine (Epilogue).

Thursday
Upgraded laptop

Installed Inkscape/X11
Installed Rhino
Installed Affinity Designer. This is not open source but a very serious and powerful competitior to Illustrator, at a fraction of price, and very intuitive. 

Read some guides to laser cutting, eg http://www.cutlasercut.com/resources/drawing-guidelines

Friday
Followed Rhino and Grasshopper webinar at 4pm.  Unfortunately Grasshopper not yet installable on Mac.

Watched Affinity Designer tutorials.

The ease of use, power and intuitive interface of this programme really appealed to me. The tutorials are very clear and easy to follow. A very elaborate and customisable guide system is also a very powerful drawing aid. The cloning, step and repeat feature is great and the zoom appears infinitesimally powerful. I used affinity and inkscape to create artwork for lasercutting.
 
KERF TEST

It's often tempting to want to jump straight to printing, but persevering with producing the Kerf test was of critical importance in Week 3. Traditionally, the term 'kerf' defines the width of the saw cut (in woodwork). This is shown clearly in the diagram below (courtesy of wikipedia). Taking this 'waste line' into account at the CAD vector drawing stage is key, especially in push fit construction, where a very close fit is necessary to achieve good structural strength. In lasercutting, the high temperature of the laser means that some materials burn away more easily on the cutting line, so the kerfing allowance needs to be varied ( ie cardboard will burn more than wood, therefore any slots for push fitting joints need to allow fr this. It has also been noted that making sure the Vector drawing is editable for future correction is also a very important point to bare in mind!  



I produced a kerf test to demonstrate what allowance should be given to 3mm cardboard for push fit construction, relative to the conditions of the machine tool (Epilogue) in our lab.

The images below show the linework for the laser to enable push fit testing across a range of increments (±0.1).
ALSO, as you can see, this also includes the creation of a CHAMFER, to aid smooth push fitting. As I found out later on, slots without chamfers make it very difficult to 'slide' into the joint, making push fitting more difficult. This can also damage and compress cardboard, thus weakening construction and structure.

 


 

This image below demonstrates a push fit tolerance that is TOO TIGHT. This shows that the cardboard has distorted beyond what should be a 90º joint. 



The image below shows how the kerf test has allowed the optimal kerf allowance without any distortion in the joint. It also provided the firmest strucural joint.




PROJECT FOR WEEK 3

I decided that I would use these findings to test and explore the strength, balance and aesthetic that I could achieve with an organic form in cardbord. This would help highlight considerations for structural integrity of my indoor garden project. I wanted the design to be light and airy - suspending plants in space. 

Initial sketches for indoor garden:

 

Whilst I would be interested in exploring construction of the inter-connecting 'X' form above, I was not convinced that cardboard would be the best material, so for the purpose of getting acquainted with the laser cutting process, I chose to develop a linear version.


I decided to draw this using Affinty Designer (not open source but a very good value and intuitive 2D drawing alternative to Adobe Illustrator) so that I could try out its cloning and use of guides.





Overall, I really liked working with Affinity. It is the most logical and intuitive drawing tool I have used to date. It also has a great range of capabilities and convertability.

NOTE: I will just mention here its cloning tool, repeated into infinity would be great for pattern work and gaming graphics. I need to do further tests to check its editability of changing the 'master' for global and efficient changes to many parts, but it looks very promising. See star repeat below.

  

Here are some images of the cardboard being cut on the lasrecutter (Epilogue).



Push fit model of structure, showing balance, strength and proportions. Seeing and holding the actual model in hand (so quickly, once artwork created) was very helpful for future development.
 
  



Download files:
Stronger2.pdf
topbott.pdf
kerftest.svg


 © Sally Williams 2015