Team Vision for Detailed Design Phase
For the Final Detailed Design Phase, the teams overall goal was to solidify a concept that we can begin building in MSDII. All drawings and schematics for both electrical and mechanical systems should be final and ready to begin construction. All components should be selected, a bill of materials should be created. The risk assessment should be revisited and updated regularly. The schedule will also need to be continuously updated, as well as a preliminary plan for MSDII developed.
- Finalize all test plans
- Finalize all drawings, schematics and simulations for mechanical and electric systems
- Create detailed schedule for next semester
- Create mechanical bill of materials
- Create mitigation plans for each risk
- Created new internal design
- Finalized previous test plans and created new ones
- Finalized all electrical drawings and mechanical simulations
- Created draft of mechanical bill of materials
- Created detailed schedule for next semester
- Updated PCB layout
- Revisited risk assessment
Prototyping, Engineering Analysis, Simulation
Design Concept FlawsAs feared during the previous Preliminary Detailed Design, our concept of a static system of nozzles used for cleaning would not hold. Due to revisiting air flow parameters and using the rating of the shop vac, we came to realize that the shop vac will not have enough air flow for a static system. As shown in the image below, the amount of nozzles we would need would divide the air flow so much that it would either generate a large amount of back pressure or have little to no air flow for cleaning.
Live document version of the code for calculating air flow parameters is here
Design Concept 2After this, we brainstormed quickly as a group and generated a second concept. This one was to use a dynamic system involving a moving air column and a guiding track. Due to the dynamic movement of the system, we came up with a Boon Arm to help deliverer air and power while limiting stress on the tubing and wiring.
Trolley Air Column (Left), Boon Arm (Right)
After going through and trying to design this concept to be manufacturable and deliver the air cleaning pressure and air flow we wanted, we ran into a major flaw. The tracks were not capable of handling such a tight corner with what we had seen. While looking around, the radius of curvature would have caused the inside to be large and a lot of unneeded travel distance.
Design Concept 3So we went back to the brainstorming and came up with another concept. This time we would keep the dynamic air column idea but use a XY stage to cover transitional movement inside the enclosure. [Similar to 3D printers]
From here, the concept is broken down into 4 major parts:
Air ColumnThe air column will be hung from the rail systems and will have a bevel gear system to help it rotate to keep nozzles interacting with the computer as it translates around the XY grid.
X Axis Rail SystemThis rail system will pull the Y Axis Rail System using an axial idea where two belts will pull on both sides of the rail system. Since the two sides will either share a shaft or a bevel gear system, they should keep the same translation rate and keep the system from binding.
Y Axis Rail SystemThis rail system will be supporting the Air Column assembly and be supported by the X Axis Rail System. This rail system will be two floating platforms on each side with two rods connecting them. This will ensure a large area for the air column to be supported and keep the rails perpendicular to the X Axis Rail System. Also, the use of 4 linear bearings for support will help in reducing the amount of torque the X Axis will need to provide to move the assembly.
Boon ArmAs the boon arm was used in the previous concept, we decided to keep it. This allows the system to be supplied air and power with a floating arm above the rail systems. This will allow the tubing to avoid unnecessary bending and pulling on seals to keep the dust from escaping the inner chamber. In more detail, the boon arm will be adjustable in length due to bearing plates that will allow it to extend and retract to the minimum and maximum lengths determined by the rail system.
Drawings, Schematics, Flow Charts, Simulations
Electrical Block DiagramBlock Diagram updated to include Motor Control. Valve controllers were re-purposed to control other 12V Electronics in the system. Some LED indicators and the 120V AC relay will be controlled with 12V logic.
SchematicsThe PCB Schematics are below. They are still in progress. Control for the motors has been added. Valve driving capabilities are still intact as a back-up option. These controller will not be populated on the circuit board if no valves will be used.
PCBThe PCB layout is still in progress with the schematic updates. With additional functionality added to the design, (Motor Control), the board is getting a bit busy. However, no functionality has been removed meaning the Valve Control is still an option if required. The board is now 4 by 5 inches. As the remaining connectors get placed, the size may grow a little.
User InterfaceThe User Interface has not changed since the last review. More thought is being put into including an LCD Display to tell the user what the system is doing. With the addition of motors, there may be more possible errors to display to the user than the original design. Below is the original User Display shown in the previous review.
Design 1 was chosen by the customer to proceed with for the construction of the enclosure. This design is with the door opening from the top and the caster wheels will attach to the bottom of the enclosure directly.
The schematic below is the same enclosure with the cover for the internal frame.
Side dimensions will be included as some corrections need to be made in terms of the numerical values of said dimensions.
Bill of Material (BOM)
Electrical Bill of MaterialsCurrent Electrical Bill of Materials include all confirmed components for the system. Some specific items are still missing such as enclosure boxes for the AC Electrical Components. The Motors have also not been selected at this time. Below is a screenshot of the Electrical BOM.
Current Excel Sheet for Electronics BOM here
Mechanical Bill of MaterialsThis Mechanical Bill of Materials include all of the main materials required to construct the enclosure. A couple of things left in general include the adapter that will attach the vacuum blower hose to the intake manifold of the enclosure and the materials required for how air will be delivered from the vacuum to the interior of the enclosure.
Current Excel Sheet for Mechanical BOM here
Electrical Test PlansSome additional test plans were created since the last review.
- Motor Test - Verifies that the PCB and code can properly drive the Motors at different speeds and directions
- Relay Test - Verifies that the Relay does not get too hot during normal operation so the user does not get burned in case of accidentally touching it's enclosure.
- XY Stage Test - Verifies that the code works to move the XY Stage to all required locations and that the motors are strong enough.
The other test plans are below:
- Door Status - Verifies the door switch works properly.
- Cleaning Cycle Time - Verifies the cleaning time is within the 1 minute customer requirement.
- Excel Sheet of All Electrical Test Plans Here
Mechanical Test PlansPrevious Test Plans Include:
- Weight of entire enclosure
- Noise level measurement
- Sealed enclosure
- Time taken to learn to use device
- Amount of dust removed after 1 full cycle
- System prep time
- Internal volume
- External depth/width
New Test Plans Include:
- Ensure rail systems function
- Ensure air column will rotate
- Simple structural test to ensure support of rail/components/computer
- How dust interacts with rail system during heavy use
- Deflection of rods to ensure elastic deformation range/stress on bearings
Design and Flowcharts
Cleaning FlowchartWith the addition of motors, the cleaning cycle flowchart needed to be updated. Below is the updated flowchart.
Risk AssessmentUpdated Risk Assessment is available in the figure below. New risks were added to the bottom along with possible mitigation plans.
- Current Excel Sheet here
- Risk Plans to be added to MSDII Schedule here
Design Review Materials
Include links to:
- Presentation and/or handouts
- Notes from review
- Action Items
Plans for next phaseA current MSDII Preliminary Schedule is below. Updates still need to be made as risk mitigation is planned.
- Preliminary MSDII PDF Available Here
Individual End of Semester Plans
- Jessica Blake's End of Semester Plan
- Megan Zielenski's End of Semester Plan
- Albert Rivas' End of Semester Plan
- Russell Lanzotti's End of Semester Plan
- Steven Jacobson's End of Semester Plan