Step 15.4: Add a Chain-Link RPR Dyad

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Step 15.4: Add a Chain-Link RPR Dyad

A Chain-Link

We want to add a Chain-Link.

The Chain-Link is represented by one of the Parts in an RPR Dyad.

We add an RPR Dyad between a Point on Slider-Set 1 and a Point on Slider-Set 2.

As always, a Dyad has two Parts and three Joints.

Add a new Part and join it with a Pin-Joint(R) to a Point on Y-Slider of Slider-Set 1

Add a new Part and join it with a Pin-Joint(R) to a Point on Y-Slider of Slider-Set 2

Join the two new Parts together with a Slide-Joint(P).

The two Parts and three Joints make the RPR Dyad.

We use the Part that is joined to Slider-Set 1 as the 'Tool-Part'. We can add a 'Solid' to this Part.

Add an RPR Dyad to the Slider Sets, one of the Parts represents the Chain-Link

Remember, Dyads always have two Parts and three Joints.

Add an R-P-R Dyad between Slider-Set 1 and Slider-Set 2

This dyad is: R(Pin-Joint) - P(Slide-Joint) - R(Pin-Joint)

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Top-Tip: Temporarily hide the Motion-Dimension FBs. See Display Filters: Hide Dimensions


STEP 1: Add a PartRed-14-1b

STEP 2: Rename PartRed-14-1b to 'Tool-Part'.

STEP 3: Add a Pin-JointRed-14-2 between the PartRed-14-1b and the start-Point of Y-Slider1

STEP 4: Add a PartRed-14-3

STEP 5: Add a Pin-JointRed-14-3 between the Part and the start-Point of Y-Slider2

The two Pin-Joints are the R joints in the R – P – R dyad

We need a P joint to complete the dyad. P = Prismatic-Joint.

Confusingly, we call a Prismatic-Joint a Slide-Joint.

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STEP 6: Add a Slide-JointRed-14-5 between the CAD-Line in PartRed-14-1b and the CAD-Line in PartRed-14-3

The Slide-Joint completes the RPR Dyad

The Part-Outlines become Green.

When you cycle the machine, you will see the RPR Dyad move with the Slider-Sets.

To show the length variation between the Pin-Joints:

STEP 7: Add a Measurement FBRed-14-6 between the Pin-Joints

The length variation between the Pin-Joints is from 100mm to 93.55mm.