## Work in Progress I am undertaking the design and fabrication of a centrifuge that can be produced and operated for less than $10. This project leverages the precision of 3D printing technology to create the necessary components affordably. By utilizing a cost-effective, non-variable DC motor, coupled with a single 9V battery and a wheel, I am able to construct a fully functional centrifuge. This innovative approach demonstrates how accessible materials and technology can be employed to develop practical scientific tools at a minimal cost. The objective is to provide a low-cost solution that can be easily replicated, promoting citizen science and making advanced laboratory equipment more accessible to a wider audience. During the process of modelling and printing, I have gone through many prototypes and revisions. The current version is vastly different than the first version, prints in half the time and uses a third of the materials. This design is not the final version as I still have problems to overcome and instabilities to manage. However, [[#Design Draft 05 - Prototype 01]] is the first operable prototype. ## Design Draft 01 This is the very first "thought to paper" I made. It was an okay proof of concept and allowed me to build on the idea to make a better design. It is quite large, clunky and too complex for what it needs to be. ![[Pasted image 20240701170036.png]] I thought this design would be sufficient, but quickly realized it's drawbacks. In this design, I intended to use an electric drill to spin the centrifuge. While that does technically work, it is not ideal or safe and does not allow repeatability/consistent experiments. This design along with it's other flaws, took around 27 hours to print. ## Design Draft 02 This draft added a base to power and hold the centrifuge, redesigned the centrifuge and although it furthered the design, was never functional. ![[Pasted image 20240701170102.png]] ![[Pasted image 20240701170017.png]] ## Design Draft 03 This draft only changed the centrifuge to lower the walls to incorporate surface area for a wheel to drive the rotation. This was also non functional. This design taught me the incorrect way to print large overhangs, as is evident in the image below. ![[Pasted image 20240701170237.png]] ## Design Draft 04 In this version I attempted to strengthen the rotational axis. This strengthening worked, but the design still failed to operate. ![[Pasted image 20240701170454.png]] ## Design Draft 05 - Prototype 01 This is the first functional version, it is far from perfect and still requires design updates. The design changed dramatically in this version. I completely overhauled the rotating tube holder, and I redesigned the electronics housing to be much more material efficient. ![[Pasted image 20240701170959.png]] As you can see in this image, I do not yet have the tolerance dialed in for the wheel that drives the rotational part. I needed to use a rubber band to make up the distance between the wheel and rotational part. The Motor housing seen on the side, was also imperfect. Sanding of the plastic was required to fix it. ![[Pasted image 20240701171203.png]] With those issues in mind, this prototype is still functional and does work for small tasks as seen here. In future designs, I will focus on reducing material requirements, fixing tolerances and creating a wider, more sturdy base in order to reduce off axis shaking caused by imbalances. I will also set out to create a proper internal housing for the battery and a switch. I have thoughts of adding an inexpensive single board computer and a cheap digital screen/LCD 7 Segment display in order to facilitate accurate experiments in regards to operation time, auto shut off, timed pulses and so on. This "smart" capability however is not currently on my task list and is at the idea stage. ![[Pasted image 20240701171510.png]]