Milestone map
Milestone map
3 milestones
Define the Mechanism and Establish Kinematic Model
1–2 weeks (3–4 hrs/week)
Select a mechanism to analyse — a four-bar linkage, slider-crank, cam-follower, gear train, or similar multi-body system. Draw the kinematic schematic: links, joints, degrees of freedom. Compute the degree of freedom (Grübler's equation) and confirm the mechanism is correctly constrained. Sketch the positions at ≥3 key configurations (e.g. dead-centre, mid-stroke, fully extended) to build intuition before formal analysis.
Proof required
Submit your kinematic model document: the mechanism description, kinematic schematic diagram with labelled links and joints, Grübler's calculation confirming degrees of freedom, and position sketches at ≥3 configurations.
What gets checked
- Kinematic schematic labels every link with a number and every joint with a type (revolute, prismatic, cam, etc.)
- Grübler's equation is applied and shows the correct degree of freedom — 1 for a single-input mechanism
- Position sketches at ≥3 distinct configurations are included and labelled
Common mistakes
- Drawing an assembly diagram rather than a kinematic schematic — kinematic schematics show only links and joints, not part geometry
- Skipping the Grübler check — a mechanism with the wrong degree of freedom count cannot be correctly analysed
Resources
Foundationstart here
Depthgo deeper
What a verifier looks for
- Confirm kinematic schematic shows only links and joints — not 3D geometry or assembly details.
- Confirm Grübler's equation is applied with all terms shown — links, joints, and degree of freedom result stated.
- Confirm position sketches show ≥3 distinct configurations with labels.
Perform Velocity and Acceleration Analysis
3–4 weeks (4–5 hrs/week)
Using graphical (velocity polygon, acceleration polygon) or analytical (vector loop equations) methods, calculate the velocity and acceleration of key points in the mechanism across a full cycle of motion. Plot velocity and acceleration versus crank angle (or input position) for at least one output point. Identify the position of maximum velocity and maximum acceleration — these govern the dynamic loads in downstream force analysis.
Proof required
Submit your kinematic analysis: velocity and acceleration calculations for ≥5 crank angle positions, clearly showing method (graphical or analytical), and velocity/acceleration vs. crank angle plots for at least one output point.
What gets checked
- Calculations show all steps — input values, intermediate results, and output values — not just final numbers
- Velocity and acceleration plots cover a full 360° cycle and identify the maximum values with their crank angle positions
- Analysis method (graphical or analytical) is stated and applied consistently throughout
Common mistakes
- Analysing only one or two positions — five positions minimum are needed to produce a meaningful plot of the kinematic cycle
- Using graphical polygons without checking the velocity scale — scale errors in graphical methods produce incorrect magnitude results
Resources
Foundationstart here
Depthgo deeper
What a verifier looks for
- Confirm calculations are shown for ≥5 crank angle positions — not just a final plot without intermediate work.
- Confirm velocity and acceleration plots cover a full 360° cycle.
- Confirm maximum values are identified with their crank angle positions.
Apply Dynamic Force Analysis and Document Results
2–3 weeks (3–4 hrs/week)
Using the acceleration results from M2, perform a dynamic force analysis of the mechanism. Apply Newton's second law to each link (F = ma for translation, M = Iα for rotation) to find the reaction forces at each joint. Summarise the design implications: which joint carries the highest force, what is the required bearing capacity at each joint, and how does the force magnitude vary over the cycle. Write a complete kinematic analysis report and have it reviewed by a mechanical engineer.
Proof required
Submit your dynamic force analysis (all calculation steps shown) and kinematic analysis report (≥1,500 words): mechanism description, kinematic model, velocity/acceleration analysis summary, dynamic force results, design implications, and review record (reviewer name, role, ≥3 challenge questions, responses).
What gets checked
- Dynamic force analysis applies Newton's second law to each link with the acceleration magnitudes from M2 — not assumed or estimated forces
- Design implications name the highest-loaded joint and state the required bearing capacity
- Review record names the reviewer, their mechanical engineering background, and documents ≥3 specific technical challenge questions
Common mistakes
- Reporting maximum joint forces without identifying which configuration produces them — the design must know when the worst-case loading occurs
- Reviewer without kinematics or dynamics background — challenge questions must probe the force analysis method, not just the report writing
Resources
Foundationstart here
Depthgo deeper
What a verifier looks for
- Engineering Design Triad check: M1–M3 together produce a design artifact (kinematic schematic + mechanism model), an analysis artifact (velocity/acceleration analysis + dynamic force calculations), and a documentation artifact (kinematic analysis report + review record) — confirm all three types are present.
- Confirm dynamic force analysis applies Newton's second law with the acceleration magnitudes from M2 — not estimated static forces.
- Confirm design implications name the critical joint and state the bearing capacity requirement.
- Confirm reviewer has mechanical engineering background and review record documents specific technical challenge questions.
- The Proof Accessibility Rule applies — GeoGebra (free), Python/matplotlib (free), MIT OCW (free), FreeCAD (free), and Open Library textbooks are all accessible without institutional licence.
Part of