Considerations and Justifications for Choice
For automated cell counting to be performed, the image of the sample slide needs to be transmitted. In this case, we planned to mount a webcam onto the eyepiece lens and send the microscope field of view to the computer. Hence, a support structure is required to affix the webcam in place and align its camera with the eyepiece lens.
Prototyping Process: Cycle of Test, Critique and Re-Design
V1
The second gif is a variation of Version 1 without any change in specification. The top segment is isolated for prototyping and testing the fit after 3D printing.
V2
Identified Issues with Previous Prototype (Critique):
- Intended to print the top and bottom segment as two separate components and screw them together afterwards for added secureness
Modifications Made (Redesign):
- Drills two screwholes by the side of the hole for the camera lens
V3
Identified Issues with Previous Prototype:
- The dimensions for the top part of the webcam holder are not customised for the webcam. This poses an issue as the webcam sticks out slightly at the bottom.
Modifications Made:
- Add an opening to the side of the camera holder to accommodate webcam specifications.
V4
Identified Issues with Previous Prototype (Critique):
- Top of the screws might stick out for screwholes located by the sides of the camera lens and affect webcam fit by pressing against it
Modifications Made (Redesign):
- Decrease thickness of material around screwholes located by the sides of the camera lens
V5
Identified Issues with Previous Prototype (Critique):
- Clipping on both sides of the top segment of the camera holder might affect ease of fitting webcam into holder
Modifications Made (Redesign):
- Remove clipping on one side of the top segment of the camera holder
V6
The 3D Prints here are split into two parts for faster printing times and easier prototyping. The camera holder still has a tube component. This has been simplified to a ring for printing as we are only interested in checking if the diameter of the ring matches the diameter of the eyepiece lens.
Identified Issues with Previous Prototype (Critique):
- After printing it and testing fit with webcam, we realised the diameter of the eyepiece lens is larger than the diameter used for the camera holder (see previous prototype pics)
Modifications Made (Redesign):
- Thinned down the wall of the camera holder to fit to diameter of eyepiece lens
V7
Identified Issues with Previous Prototype (Critique):
-
The diameters of holes for both top (webcam lens) and bottom (eyepieces lens tube) parts were initially the same for the previous prototype. However, the diameter of the webcam lens is smaller than the diameter of the eyepiece lens.
Modifications Made (Redesign):
- Decrease diameter of the hole for the top segment of camera holder for webcam lens to allow for snug fit and webcam does not wobble on top of eyepiece lens
V8
Identified Issues with Previous Prototype (Critique):
- NIL
Modifications Made (Redesign):
- Confirmed lens do fit after printing and now put them together to print the full prototype
V9
Identified Issues with Previous Prototype (Critique):
- The tube is affixed to the tip of the eyepiece lens, allowing the eyepiece to rotate freely. This is an issue as the rotation of the eyepiece interferes with the setup.
Modifications Made (Redesign):
- Elongated tube such that the holder now affixes onto the tube of the eyepiece lens as opposed to the tip of the eyepiece lens, reducing rotational motion.
- Drilled a hole inside the tube of the camera holder for screwing. This helps to adjust the tightness of the camera holder so it does not rotate freely around the eyepiece lens.