To learn about dyads
To learn how to add dyads to kinematic-chains. You will see that you can, in principle, add any number of dyads to each kinematic-chain.
In this tutorial, we will:
|1.||Add RRR and RRP dyads to build slightly more complex kinematic-chains.|
|2.||Show that a:|
|a.||Slide-Joint does not need to use the CAD-Line along the Part's centre.|
|b.||Pin-Joint does not necessarily need to use the start-Point or end-Point of the CAD-Line along the Part's centre.|
|3.||Learn a little about six-bar* kinematic-chains.|
* The term 'bar' is used more frequently than 'Part' when applied to mechanisms such as: four-bar, six-bar, eight-bar.
Add more Dyads
Then, experiment with different possibilities of the three joints in a Dyad: RRR, RRP, RPR, RPP, PRP
Also, change the driven Part from a Rocker to a Slider.
Dyads - see Kinematics-Tree.
A new dyad does not change the number of degrees-of-freedom (DOF) in a kinematic-chain.
Why? Because a dyad has two Parts and three Joints.
Thus, the change to the total Degrees-of-Freedom = +6 + (– 6) = 0(Zero).
* Parts on a Plane.
£ Pin-Joint or Slide-Joints added to Parts on a Plane.
Motion-Parts see the Kinematics-Tree
A Motion-Part does not change the degrees-of-freedom of a kinematic-chain.
Why? Because a Motion-Part has one Part, one Joint and one Motion-Dimension (a defined coordinate).
Thus, the change to the total Degrees-of-Freedom = +3 +(–2) + (–1) = 0(Zero).
Kinematically-defined Parts & Green Parts
'If all the Parts have Green Part-Outlines before you add a Dyad, the Parts will also be Green after you add a Dyad'.
'If all the Parts have Green Part-Outlines before you add a Motion-Part, the Parts will also be Green after you add a Motion-Part.'