1. Many pipette tips fall out of the wheel and refeeder mechanism completely, which forces us to feed pipette tips into the refeeder by hand every now and then, which is inconvenient. Further adjustments can be made to the wheel to prevent pipette tips from falling out of the wheel but not falling onto the refeeder. For instance, we could add an additional component to prevent pipette tips from falling out of the wheel before it reaches the top where they are supposed to fall out of the wheel.
2. Some of the pipette tips are stacked on top of each other and stuck to each other, even when it comes in bulk in a bag. This may cause our system to malfunction as our project is calibrated only for single pipette tips (i.e. the stacked tips may jam the 3D printer movement as the pipette is not lifted high enough for multiple stacked pipette tips and the tips will collide with the pipette tip box). Additional modifications can be made to separate these tips for them to be pried apart manually by humans.
Stacked pipette tips are longer than single pipette tips and may mess up the functioning of our prototype.
3. There was also the possibility of the ramp getting jammed by the pipette tips falling onto the ramp in unexpected ways, as shown in the following pictures. Additional steps can be taken to rectify these situations. For example, in the case of the pipette tip falling in the reverse direction, the width of the ramp can be adjusted such that subsequent tips that fall in will push the stuck pipette tip into the correct orientation.
The pipette tip might fall horizontally and block the incoming tips.
The pipette tip might fall in the reverse direction and block incoming pipette tips from sliding into the ramp successfully.