PROCESS sewing machine .md 2.63 KB
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**PROCESS: sewing machine group**

 

*Team: Lucie, Ombeline and Karine*

 

Since we got the idea of a wooden sewing machine, most of the work was to understand the mechanism of the machine. We did many researches about this subject. 

 

At the beginning, we made a first test of the complete mechanism. 

<video src="/Users/ombeline/Desktop/1 test - complete mecanism.mp4"></video>

Seeing that it did not work, we focused on more specific details before trying to make the whole object work. We tested flexible wooden chains and different gears. 

<video src="/Users/ombeline/Desktop/2 test - wooden chains.mp4"></video>

<video src="/Users/ombeline/Desktop/3 test - gears.mp4"></video>

<video src="/Users/ombeline/Desktop/5 test - gears.mp4"></video>

The gears worked well. Starting from there, we redesigned the whole mechanism. 

 ![plans Autocad](/Users/ombeline/Desktop/plans Autocad.jpg)



Then, we made several tests of the complete mechanism, changing little details between each test on different materials: hardboard, plexiglass, plywood ... ![prototypes evolution](/Users/ombeline/Desktop/prototypes evolution.jpg)

But the laser cut was not precise enough and we had to change all the interlocking pieces each time. Plus, the thickness of the material varied between all different materials, we decided to stop doing tests on every material we could think of and to search for the optimal material for our machine. 

 

Then, we tested different materials on their rigidity, their resistance to water, their price... We summarized our research in this comparative table. ![comparative table of materials](/Users/ombeline/Desktop/comparative table of materials.png)

After we received confirmation by the Indians of the accessibility of the material in Kerala, we noticed that the material that had the best quality / price report was the MDF.  

From there, we were able to repeat our tests and we made our first MDF prototype. ![MDF prototype](/Users/ombeline/Desktop/MDF prototype.jpg)

A new problem arrived : we had gears at 90° with each other. Consequently, they jam and block all the mechanism. Then, we found three solutions to solve this problem. Either we sand down an angle by hand, but it is not precise and too long. Either we make gears with slanted teeth with the 3D printer, but it would break our idea of making the machine in one material and for it to be cheap and simple. Or, we mill the gears with the CNC using a beveled wick. We chose the last solution.  

![ milled gears](/Users/ombeline/Desktop/ milled gears.png) 

At this stage, the general mechanism of the sewing machine works, but there is still a problem with the rotating hook below.