Week 3 Assignment: "Infinite Plus" Joint

In this week, our assignment was to design a joint and 3D print it. The joint needed to fit to 2 to 4 wooden rods/profile and I decided to make mine fit to 4 wooden rods. After spending several hours thinking and working on it, the final outcome was the above pictures. I called it the "infinite plus" joint as it contained four infinity symbols, two on the top and two on the bottom side, with a plus sign in the middle. I believe it is a quite stable structure and could hold woods in several ways. If you are interested in how I made it, please keep reading...

Steps:
1. Sketching

2. 3D Modeling

3. 3D Printing

4. Removing Supports

5. Smoothing & Finalizing

6. Final Work

7. Collaboration &Reflection

20 mm (d) 50 mm (h) round wooden rod x 4

Rhino 7

Cura LulzBot

3D printing machine

Smoothing tools: needle nose plier, sandpaper, scraper...

When I first saw this assignment, I didn't know how large the wood rods were and how heavy weight they could lift. Therefore, I had a really unrealistic idea, which was to build a little stool with a round top and could connect to four rods. However, later I found out that my rods were quite thin and my idea was impossible so I tried to modify it. Finally I designed the top and the bottom side of my work to be the same shape, each with two infinity symbols connecting the cylinders together.

The problem I faced next was that I was not sure that my joint was stable enough because the infinity symbols made the connections to be quite thin and was easy to be bent. I thought of connecting the bottom of all the infinity symbols in the middle part of the joint but I was not sure how I could make that using the software. Since I had the basic design of my joint with some details I needed to try on software and modify, I moved to the next step.

I started building my 3D model by using the SubD Mode. The mode have different functions and function logos compare to the Standard Mode. I started by first drew 4 curves and used the pipe function to make the curves into 4 pipes. I thought I could add the top and bottom face and joint them. However, I realized that since the pipe was a subD material and the two faces were not, I could not joint them. Therefore, I decided to change my method and create 4 cylinders using the cylinder function in the SubD Mode. Since the mode was for modeling organic materials with more natural shapes, the cylinders being created had round edges at both top and bottom faces. I used the add crease function to make them look more like normal cylinders.

After that, I selected the parts that needed to be connected and use the bridge function to connect them. After several miner adjustment on the shapes, the four infinitives connected together was showed on my computer. My next problem was how to add more connections in the middle to make my joint more stable. My first try was just open some holes under the middle of the downside faces of the infinity shapes. However, the bridges being created were quite strange with some thin edges that were difficult to print. Therefore, I changed the arrangements a few times and finally find the right solution: extruding the middle part of the bottom sides of the infinite shapes, making a hole at the side face of the extruded part and bridging them. The outcome was showed on the above picture and could possibly be printed.

Under professor Garcia's guides, the printing process went pretty smooth. I saved my 3D model as a stl file and sent it to the computer in the lab. The file was opened in Cura LulzBot which prepared it for printing. In the software, I checked the printing process by viewing each layer that would be printed.

After making sure all the settings were right, I implanted the printing code to the SD card from one of the printing machines and started the 3D printing process. The printing failed at the first time in the machine's preparing phase. After talking to the professor I realized that it stoped because the printing area was not clean enough with some remained little plastic pieces. After cleaning them up, the machine functioned normally and the printing process truly started.

I waited until the first layer was printed and made sure that it looked just like how the computer showed and went home. The printing process would take about 5 hours and I decided to pick up my design on the next day.

On the next day, I went to school and saw my work. The printing process was finished. The next step was to remove the supports. I found the computer really smart as it could automatically form helpful supports which ensured the outcome to be exactly what I wanted. To remove the supports, I used a needle nose plier. The process was not that hard and I finished it quickly. An import point was that we need to throw the plastic stands being remove to a box for plastic recycle. This was really a right thing to do.

Lastly, we had to make the edges of the model more smooth. The process was similar to smoothing wood in last week. This time, we were still using the same tools. The process was not hard but needed patience. After smoothing the edges, I cut the wooden rods I need and assembled my final work.

In this phase, I tried several different ways to assemble the wood rods and my joint. I realized that the wood rods have some minor difference in diameter size even when they were cut from the same long wood rod. The above pictures as well as the pictures in the introduction part are some assemble ways I tried.

In the above picture, Huaze and I tried to create a scene which was called "Warrior vs. Cannon" using our 3D joints. It was quite interesting to play with something made by ourselves. We really enjoyed the process.

This was the first time I tried to both design and create a 3D model on computer. I learnt how to use the SubD Mode in Rhino 7 as well as how to use the 3D printing machine. I found the process not as difficult as I thought. I realized that I could build many little things in real life using the skills I learnt. They were really useful. In the future, I hope I could build more creative products using these techniques, practice more, and learn more complex skills about 3D printing.