About my model

I officially finished my first model this week. Everything looks fine except the surface kind of looks dirty. In general, I'm pretty happy with what I have right now and I'm hoping that I will do better next time.

I started another model this week. It is similar to the old one but it is a square in the middle. The purpose of this project is to compare the flow in a square tube verses a circular tube and see if it causes the particles to move differently in the fluid.

I first designed the square tube in Solidworks. The length of the side of the square is the same as the diameter of the circular tube. The length of them is the same. After finishing the tube part in Solidworks, I imported the entire file into 3Matics, another 3D design app. I copied and pasted the connectors from the circular tube and merged it onto the square one.

After that, I repeated the same process as the straight tube: printing, removing the support, building the box and adding the silicone. Nothing is too interesting about this process as I've already done it once, but I did get better at building the box.

About the 3D design part

I finished the design last week but for some reason, the part is not the right size. As a result, I have to shrink the model down to the right size. I think this happened because the default unit in the software was inches and I measured everything in centimeters. When I shrink the entire thing down by the right amount, the side that is designed to fit the syringe became too small. Thus I redesigned that part and printed it.

One really interesting fact about printing this is the stereolithography printer print the part upside down. Because the laser and the liquid are at the bottom of the printer, the platform has to be on the top.

The printing process turned out to be pretty successful. It took about four hours for the part to be printed. However, the opening that is designed to hold the syringe seems to be too small.

After the printing process is completed, I put the part in isopropyl alcohol to remove the sticky things on the surface. The alcohol didn't do its job, and the part is still sticky after I took it out of the container. I had to start removing the support as the alcohol might change the chemical properties of the part if I leave it in the alcohol for too long. As the part is not completely solid and smooth on the surface, I put it in the UV oven for 30 minutes.

The part seems fine when it is printed, the only problem is that the four holes are too big to hold the part that is supposed to fit in there. To fit it perfectly, I put tape around hold to tighten it up. It now works nicely.