Preliminary Detailed Design
Table of Contents
All documents that were generated as a result of this phase can be found here.
Team Vision for Preliminary Detailed Design Phase
Throughout the Preliminary Detailed Design phase, our project team wanted to gain a high level grasp on the specific features that would be included in our shredding system. Initially we wanted to complete some CAD models of the individual components and begin a basic level assembly based on other operational shredders. From the CAD models we sought to develop some simulations to test their strength and functionality and ensure our design is feasible. Using our models, we want to develop a first iteration bill of materials with as much specificity as current possible. Finally, along with updating all existing documents, we wish to develop thorough test procedures so that once our design has gone through the prototyping phase we may begin testing our engineering metrics.
In this phase we were able to develop several CAD models that accurately represent the system we envisioned during our systems level design phase. Specifically, we were able to develop a drawing package for the shredding blades and the blade spacer components. A model was developed for the hopper system used to load plastic bottles to our blades as well. The power supply and transfer of energy system is still in development, but should be completed within the early steps of our Detailed Design phase. The Bill of Materials at this stage has some high level details of material need and quantity. More information will continue to be added as we decide more on a set of materials and functions. There are several detailed test plans set up for when we are ready to prototype our design. These test plans need more detail in their assessments, however that will come as we gain more insight on our final design in the next phase. Overall, this phase was a great success for our group and we made strong progress towards our technical designs.
The following images represent the testing and results of a similar shredder design which is used to shred breadfruit. This shows the potential our design has for success and different issues that we need to address such as chip sizing.
The following images show justification for the remolding of our plastic. These are pucks made from HDPE that was shredded and remolded under heat.
The following Directory contains several documents justifying our designs. This includes some of our feasibility analysis as well.
Shredder Component Part Drawings
The team is in the process of developing a set of detailed part drawings for each component in our detailed design. All of the documents to date can be found in our directory which is available here.
Our Assemblies and drawings can be seen below. Included below are our shredder assembly, blade designs, and the hopper.
The bicycle power source is a work in progress in CAD and the analysis and research done on that can be found here.
Engineering Analysis was conducted on the Shredder blades to observe their durability under expected conditions. The first image represents the anticipated upper limit of the load that PET would apply to our blades. As you can see there is absolutely no risk of failure represented in this analysis indicating no damage should be seen if proper materials are used.
In this next test, we used 1500 Newtons to represent an extreme upper limit that our system could potentially see. This case represents a scenario in which a very strong material with a very high shear strength enters the system and the operator applies an excessive amount of force to shred the item. This would be an object that cannot feasibly be shredded by human power in our system and is therefore an extreme test.
Even under these extreme conditions, there is very little deformation of the blades and this indicates that, provided we have a proper shear pin fail safe, we should see no issues related to blade damage from normal use.
Bill of Material (BOM)
The current Bill of Materials is seen below and a link to the live document can be found here: Bill of Materials.
In order to conduct appropriate testing of our system once we begin prototyping, we have developed a set of test plans to ensure we meet our predetermined engineering metrics. Each test plan has its own document to outline the objective, procedure, ownership, and other significant details necessary to complete the test.
A link to the directory containing all of our testing plans can be found here: Testing Plans.
The tests we plan to run consist of the following:
- Chip size and sieve effectiveness analysis
- Shredding force and shear pin testing
- Shredding Apparatus testing
- Stand stability testing
- Shredded Bottles per hour
- Ergonomic fatigue testing
- Mean time between failures
Risk AssessmentThe following is an Image of our updated Risk assessment.
A link to the live document can be found here: Risk Management.
Industrial Design Progress
Afifi is a key component of the success of this project and he has been doing extensive research and work on various products and cultural solutions we can provide to the nations we are helping. His progress book and all of his research, sketches, and plans can be found in the following directory.
Plans for next phase
During the previous phase we were able to complete or at least start our CAD and BOM packages for all of our subsystems and components. The next phase it will be critical to finalize all of these and decide on our materials and specifics for our BOM. Consulting Experts is an aspect of our research we still need to complete in Phase IV.
Below is our project plan and the link to the live document.
The team developed a Team Vision and Individual visions for next semester. They are outlined here.
- The following are links to our individual three week plans :
- David Swerzenski Three Week Plan.
- Evan Oslakovich Three Week Plan.
- Michael Kist Three Week Plan.