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Basic Requirements needed for a Tolerance Simulation Model:

The required Inputs for MVM Modeling are, Part Geometry, Assembly Method Moves, Part Tolerances and Measurements.

 

Part Geometry:

The first requirement of a model is the creation of part geometry. All part components that are analyzed have to be defined in the model.

 

 

 

 

Assembly Sequence:

This information is based on how the part are sequentially put together in an assembly. This information is required for any model containing two or more parts. Within 3DCS, a Move defines how one part locates to another.  Since each part has unique locators, appropriate Moves have to be selected to assemble different parts together.  Multiple moves can be defined to build an entire assembly.

 

This Model has sub-assembly Modeling Process, It includes two sub assemblies, two Pivot Assembly and the Lever Assembly. These sub-assemblies need to be assembled first.

 

 

Pivot Assembly

Coincidence Constraint between Pivot and Select Pin

 

 

Contact Constraint between Pivot and Select Pin

 

 

 

 

 

Fix Together Constraint between  Pivot and Select Pin

 

 

Lever Assembly

Coincidence Constraint between L Lever and Lever Pin

 

 

Contact Constraint between L Lever and Lever Pin

 

 

Fix Together Constraint between L Lever and Lever Pin

 

Main Assembly

Fixed Constraint on Frame

 

 

 

Contact Constraint between Frame and Mounting Block

 

Coincidence Constraint between Frame and Block

 

Coincidence Constraint between Frame and Block

 

 

Coincidence Constraint between Pivot and Mounting Block

 

Contact Constraint between Pivot and Mounting Block

 

Coincidence Constraint between Stick and Select Pin

 

Offset Constraint between Stick and Pivot

 

 

 

Offset Constraint between Stick and Frame

 

 

Coincidence Constraint between Link and Select Pin

 

 

 

Coincidence Constraint between Link and L Lever

 

 

 

Offset Constraint between L Lever and Frame

 

 

Revolute Joint between Lever and Frame

 

 

 

Tolerances:

3DCS MVM models are built and simulated to study the effects of tolerances in an assembly. Tolerances on the parts define the input variation. Proper definition and application of tolerances to the modeled areas of the parts are required.

 

Frame

 

Pivot

 

Select Pin

 

L Lever

 

 

Lever Pin

 

 

 

Mounting Block

 

 

 

Measurement Goal:

To understand the effects of Tolerances in a model, Measurements are defined in different areas of the model. Most measures will be made at the final assembly level (root level) of the model. These Measures record the variation created in different areas of an assembly caused by the Parts, Tolerances and Assembly Method.

    These are the Measure Results that are Required from the Model

 

1.  Measure the top of the Stick from Nominal in Y Direction to be within +/-1.

2.  Measure the top of the Stick from Nominal in X Direction to be within +/-1.

 

3. Check the Assembly Level Variation of the Spherical pin position on the top of the Stick to be within +/- 3 per the Assembly Level Position tolerance on the stick knob

 

4. Determine the variation of the gap between Mounting Block and Pivot in the X Direction

 

5. Determine the variation of the gap between the Pivot and Stick in the X- Direction.

 

6. To Determine the variation Gap between the Sphere Surface of the Stick and the Frame in the extreme position of the assembly.