Preliminary Detailed Design
Table of Contents
Team Vision for Preliminary Detailed Design Phase
Feasibility: Prototyping, Analysis, SimulationStorage
In order to estimate the required critical angle to get the tips start sliding on the storage ramp we made few assumptions. Assuming the tips are cylindrical shaped plastic and that it slides without slipping we can apply a simple friction equation to estimate the slider angle. These assumptions allow us to get a minimal angle since the tips will have less friction The angle calculated was 45 deg.
SorterThe construction below was used to test the feasibility of the blockade sorter design. Pipette tips were dropped at the top in different orientations and amounts with the device at a 45 degree angle.
After performing this test we are confident in the feasibility of this sorter design. However occasionally a tip would get stuck and the top and would need to shaken free. Further testing is planned at different angles, drop heights, and shaker configurations to determine the necessity of shaker motors.
Prototype lanes were made on aluminium on different thicknesses and different sized lanes. Below are videos on how the pipettes roll down them. We can see that the pipettes do not slide down smoothly due to the following reasons.
• The small extrusions on the pipettes makes it difficult to slide down when the lane diameter is too small. The minimum diameter had to be above 0.250”.
various lane widths with pipettes(from left to right - 0.271 inches, 0.250 inches with a chamfer, 0.180
• When the material is too thick it makes it makes the pipettes difficult to slide down, therefore a chamfer had to be added on one side of the plate. The chamfers could not be added when the lanes were very close. We had to consider having alternate lanes.
• The diameter of the lanes changes due to the long nature of the lanes as they are getting bent.
• The pipettes can’t be filled by just sliding the tip box under it as the tips can’t be easily aligned with the box.
Due to these problems the team has decided to use rods instead of plates giving an ease of manufacture and also gives better results when pipettes slide down.
Drawings, Schematics, Flow Charts, Simulations
Bill of Material (BOM)
Plans for next phase
Individual Three Week Plans: