<< Click to Display Table of Contents >> Navigation: Getting Started Tutorials - MechDesigner > Tutorial 6: Cams: Flat, Barrel, Globoidal, 'Slot' > 6D: Slot-Cams > Step 6D2.0: DESIGN 2: The Target Design > Step 6D2.2: Prep 2B: Add R-R-P dyad and Rocker |
Add a R-R-P dyad:
•Add two Parts (A and B)
•Join a Part(A) to the Orbiting Gear with a Pin-Joint
•Join Part(B) to the Base-Part with a Slide-Joint. This is the sliding-Part. We do not know its motion unless we measure its motion.
•Join Part A to Part B with a Pin-Joint
Dyads are two Parts and three Joints. There are five possible dyads in Planar Kinematics: R-R-R, R-R-P, R-P-R, R-P-P and P-R-P. •The R stands for Revolute. This is identical to a Pin-Joint •The P stands for Prismatic. This is identical to a Slide-Joint A dyad does not add or remove degrees-of-freedom. •2 Parts add 2 × 3 degrees-of-freedom •3 Joints subtract 3 × 2 degrees-of-freedom |
STEP 1: Add the R-R-P dyad Add the two Parts: 1.Kinematic-elements toolbar > Add Part | Drag to add the Part(A) 2.Kinematic-elements toolbar > Add Part | Drag to add the Part(B)
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Add a Pin-Joint. 1.Kinematic-elements toolbar > Add Pin-Joint Click the Point - start-Point of Part(A) Click the Point - the Point that has Trace-Point on the small gear. This is the R in the R-R-P dyad. |
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Add a Slide-Joint 1.Kinematic-elements toolbar > Add Slide-Joint Click the Horizontal Line in the Base-Part Click the Line along the center of the Part(B) This is the P in the R-R-P dyad. |
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Add a Pin-Joint. 1.Kinematic-elements toolbar > Add Pin-Joint Click the Point (end-Point of Part(A) Click the Point (start-Point of Part(B). This is the R in the R-R-P dyad.
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The color of the Parts change to indicate they are kinematically-defined, again. The two Parts are the new R-R-P dyad. STEP 2: Cycle (ALT+C) to make sure the Parts can complete the cycle. STEP 3: Edit the length of Part Edit its length to be approximately equal to the radius of the Trace-Point. When length of Part is approximately equal to the radius as the Trace-Point, the sliding-Part will approximately dwell at one end of the slide movement. In my model, the length of Part is 370mm. |