Add the RRR Dyad

Add a R-R-P Dyad:

Add two Parts
Join a Part(A)to the Orbiting Gear with a Pin-Joint
Join the other 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

tog_minusQuick Reminder of Dyads

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 Part adds 2 × 3 Degrees-of-freedom.
3 Joints subtracts 3 × 2 degrees-of-freedom.

To add a Dyad, add two Parts and three Joints.

tog_minusPreparation 2B: 'Add an R-R-P Dyad'

6D2-1-010

STEP 1: Add the R-R-P Dyad

Add the two Parts:

1.Kinematic-elements toolbar > Add Part | Drag to add the Part(1)
2.Kinematic-elements toolbar > Add Part | Drag to add the Part(2)

 

 

 

6D2-1-011

Add a Pin-Joint.

1.Kinematic-elements toolbar > Add Pin-Joint

Click the PointRed-14-1b - start-Point of Part(1)

Click the PointRed-14-2  - the Point that has Trace-Point on the small gear.

This is the R in the R-R-P Dyad.

6D2-1-012

Add a Slide-Joint

1.Kinematic-elements toolbar > Add Slide-Joint

Click the Horizontal LineRed-14-1b in the Base-Part

Click the LineRed-14-2 along the centre of the Part(2)

This is the P in the R-R-P Dyad.

6D2-1-013

Add a Pin-Joint.

1.Kinematic-elements toolbar > Add Pin-Joint

Click the PointRed-14-1b (end-Point of Part(1)

Click the PointRed-14-2 (start-Point of Part(2).

This is the R in the R-R-P Dyad.

 

 

6D2-1-014

The Parts become Green again. The two Parts are kinematically 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 Red-14-1b

Edit its length to be approximately equal to the radius of the Trace-PointRed-14-2.

When length of PartRed-14-1b is approximately equal to the radius as the Trace-PointRed-14-2, the sliding-PartRed-14-3 will approximately dwell at one end of the slide movement.

In my model, the length of PartRed-14-1b is 370mm.

Tutorials and Reference Help Files for MechDesigner and MotionDesigner 14.2 + © Machine, Cam, Mechanism, and Motion Design Software by PSMotion Ltd