Team Vision for Detailed Design PhaseThis phase was focused on detailed design for low risk items such as the structure.
- What did your team plan to do during this phase?
- Decide upon structure type and linear motion solutions.
- Create a 3D model for the structure.
- Demonstrate working extruder prototype.
- Sent out more letters for sponsorship.
- What did your team actually accomplish during this
- We decided to move forward with an XYZ Cartesian. For linear guide rails we are looking to use carriage and rollers and for actuation, we are looking into ball/lead screws.
- A full 3D model of the structure and animation of the printer assembly has been completed with exception to fasteners.
- We were able to demonstrate successful extrusion with our latest extruder and auger prototypes.
- Sent out roughly 15 letters for sponsorship requisition.
Prototyping, Engineering Analysis, SimulationsDuring this phase additional prototyping, analysis and simulation were performed by each team.
MechanicalPrototyping of the extruder was continued. A successful extrusion example is shown below.
This auger iteration had a smaller diameter allowing it to turn more freely. Additionally, the mixture used was a derivative of the Portland Cement Mortar Mix which worked fairly well.
A static bending analysis for the x- and y-axes was completed to facilitate selection of aluminum extrusion profile. The maximum deflection was calculated for 6 different profiles from FramingTech. Three loads were considered: our estimate of the extruder weight, 2x this estimate, and 3x this estimate.
In the y-axis, the beam was assumed to have pin supports at each end and the extruder was applied as a static point load at every 10mm along an assumed 1.5m long beam.
In the x-axis, the beam was considered as a cantilever beam from a fixed support at the vertical beam toward the extremities. A worst-case analysis was performed by approximating the applied load as the sum of the entire extruder load (with factors of safety) as well as the weight of the y-axis beam.
From this analysis, we conclude that 45x45 profile will be used for the machine. A maximum deflection of 0.00085m was calculated in the y-axis under the extruder load with a factor of safety of 3. A maximum deflection of 0.00057m was calculated in the x-axis under the extruder load with a factor of safety of 3.
The matlab file used for the analysis is found here.
ElectricalA table displaying all of the variables and results in the system wide power analysis. The results yield that a 200W power supply should suffice for all functionalities, with a built in safety factor. For in-depth description see the "System Wide Power Analysis" document below.
A few files are provided to show analysis for System Power, Power Consumption, and End-Stop Selection.
SoftwareA Cura profile has been created for an example print of the RIT logo. The Cura settings are shown in the images below. The tool-path has been recorded and is shown in the video below.
Drawings, Schematics, Flow Charts, SimulationsBelow are the schematics that are currently used to model the system.
MechanicalStructure CAD diagrams are found below. Additionally, a GIF shows the movement paths for the structure assembly.
ElectricalFigures 1, 3, 5: Schematics of model specific motor simulations performed in MATLAB/Simulink.
Figures 2, 4, 6: Scope captures of the simulation results. From the results, model specific performance can be analyzed in the electrical environment of the project and under the mechanical loads that the motors may be presented with. The plots display: voltage per phase, current per phase, electromagnetic torque, angular velocity, and angular displacement.
SoftwareThe overall library of instructions to setup a new Duet 2 Wifi controller board are found here. Specifically, to setup the controller board from scratch, follow the instruction found here.
Bill of Material (BOM)
Test PlansSince the Preliminary Detailed Design review, the test plans have been updated to the excel sheet. Test Plans
Risk AssessmentThe updated risk management document: Detailed Design Risk Assessment Chart. The previous phase risk assessment and new risk assessment preview PNG can be found below.
Design Review MaterialsPre-Read
Plans for next phase
The three week plans for the detailed design review are found below.
This completes the MSDI phase of senior design. Moving forward, MSDII will begin with prototyping and testing of each axis (X, Y, Z) one by one. Preparation for MSDII included constructing a wooden extrusion prototype.