Digital Making | A Joint Effort
Week 4 Recap
Last week our effort to propose an effective joint solution was weak. We had an idea of a moving joint but no clear picture of how to apply it.
This is what we had:
This was our concept borrowed from a pre-existing model. The joint essentially allowed two members to pivot as the joint was connected to a center ring. However, this require 5 separate parts, was not ideal and not very strong either.
Week 5
This week, digital making and fabrication paired up again and we reassigned ourselves into smaller groups to handle each task. Both Bob and Simon worked together into creating a dynamic joint as the idea of a kinetic skin was floating around. Which resulted in this:
The first attempt at printing this joint resulted in a failure. While the Grasshopper model showed a perfect fitting ball and socket, the ball part of this joint was simply too big and wouldn’t allow the two halves of the socket to close together.
After catering for the over sized ball and other tolerances, a working dynamic joint was printed. The ball rotates freely around the socket whilst being kept in place, unable to pop out.
In the mean time, whilst Bob continued his work on creating a static component to his dynamic joint. I pursued a different type of static joint.
This joint takes on more of an organic, relaxed mesh. As iterations of the pavilion were shown to the group, it became apparent that we may not even need a dynamic joint at all.
Experimentation
The above prints were all printed in PLA for a quick and easy prototype. It has been discussed and settled upon that the actual joints will be printed in ABS, which is far better suited for the outdoors (as PLA is food based and biodegradable).
In relation to getting a better understanding of the material as well as attempting to increase production speed, I experimented with ABS and acetone smoothing.
Essentially, acetone smoothing is the process of using paper towel (or any absorbent) to soak up acetone. Placing that in a sealed container with the ABS print inside. That way the vapors that are trapped in the container begin melting and smoothing out the print. It is important that the ABS and acetone don’t come in contact.
The reasoning for this experimentation is that, if we are able to use a lower resolution and still produce a smooth finish, we can effectively cut print times in half.
Before:
As shown above, the support material leaves behind artifacts, rough patches of material. Whilst they have been filed down to a degree, they are still an eye sore.
After:
The joint was originally printed in 0.2mm resolution like all the joints above. After being exposed to the vapors, the support artifacts have blended in, although still visible, they are drastically less noticeable. The print has also changed from a matte finish to a more glossy, smooth finish.
Another test will be held to see if the support material can be entirely blended into the joint as long as the print hasn’t received any post production work (i.e. filing, sanding).
To conclude, the acetone smoothing was a success. The print also had layers which had split slightly but after the smoothing process they had welded themselves back together.
