Using Traction and Belts for Layout Sketches
The Traction relation and the Belt/Chain tool (Blocks toolbar) enable you to use layout sketches to create these mechanisms:
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Multiple gear sets
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Cable and belt pulleys
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Chain sprocket systems
Traction
The Traction relation creates relative rotation constraints between sketch entities by adding a tangent relation between blocks that represent pulleys or sprockets.
To add traction relation:
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Sketch multiple circular or linear entities to represent gears, rack and pinion mechanisms, etc.
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Make each entity a separate block.
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Add relations and dimensions to eliminate motion not related to the mechanism.
Limit the use of the Fix relation, for example to the center of one circle. Use horizontal and vertical relations, dimensions, or construction geometry to locate the centers of additional circles or sketch entities. Adding multiple fix relations potentially restricts the model's degrees of freedom.
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In the graphics area, select two sketch entities to which you want to add relative rotation constraints.
Belt/Chain Tool
To use the belt chain tool:
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Sketch multiple circular entities to represent belt members.
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Make each sketch entity into a block.
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Click Belt/Chain (Blocks toolbar) or Tools, Sketch Entities, Belt/Chain.
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Add relations and dimensions to eliminate motion not related to the mechanism.
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Add belt members and belt to create the mechanism.