3D Printing a rotating pen stand

I wanted to have a pen stand where I could put all my pen on desk, but I wanted it to be little unique. Hence, I made it rotating so that I can pick up a pen from any position and it will rotate itself to balance its weight. Now not only I have my unique pen stand but also, I learned few lessons about 3D printing and design. Thank you 3DEXPERIENCE LAB India (@SG and team:  @NM @AH and @DK and ) for your help!

I had a rough idea of how I wanted the stand to look like and this was my second time 3d printing a model. So, it started as simple procedural design from base and building up to the topmost roller. But if I had printed it as it is then it would not have rotated. There comes first lesson. If I wanted to have a rotating part, then I would have to dissemble the mechanism in several components. So, I redesigned each part separately and did the assembly in model. But the connecting rods could not be printed in standing position, and they needed holes on base which could hold them. This made me redesign part. The second lesson came along; iterative design is part of the process and there will be no final version to a product. Now I tried to create the assembly, but the parts did not fit, as I should have ensured that the connecting dimensions were consistent with each other. This was third lesson and with it I redesigned the parts having proper dimensions. After redesign, I downloaded the 3d models and printed the parts. When the print was complete, the parts did not fit each other, despite given fitting and rotating tolerance as well as fillets to sharp ends. Finally, I needed to use file to make the parts fit each other and the assembly is now complete. The lesson here is to give appropriate tolerances and fillets which ensure proper fitting and moving tolerances in the parts.

The images with this post show how the final assembly looks in SolidWorks and in reality. This idea does not need to stop here. I can and I will try to make a virtual twin of this model to simulate the structural stability of the product and redesign it based on the simulation results. This thought shows that an innovator / engineer should not stop at finding solution to a problem but be ready to take the innovation one step ahead.

Thank you 3DEXPERIENCE LAB India again!

[P.S.: First image shows the 3d Model, 2nd shows printed parts, 3rd one is assembly and last one shows how pen are kept in the stand.]