http://blogs.solidworks.com/solidworksblog/2015/10/mbdimplementation-10-dos-and-10-donts-dont-hesitate-part-1.html

Create MBE Vision Plan Identify Data Needs Assess PMI Consumption

3 DimXperts 2D Drawings Introduced with version 2007 3D Parts Introduced with version 2008 3D Assemblies Introduced with version 2016* *SOLIDWORKS MBD license required

Machined Parts Milled Drilled Turned Geometric and Plus-Minus Tolerance

Sheetmetal Bends not supported --- Use Reference Dimension Prismatic type features are supported (planes, holes, slots) Molded/Casted Parts Draft not supported Profile tolerancing is supported Use reference geometry (planes and intersections) Special Geometries Including gears, threads and cams

Hole Cone Countersink Counterbore Slot Notch Boss Cylinder Plane Pocket Surface Chamfer Fillet Width

Intersect Plane Intersect Line Intersect Point Plane intersection between a cylinder and a cone Line intersection between a two planes Point intersection between a cylinder and a plane

Model faces colored based on status Green = Fully Constrained Yellow = Under Constrained Red = Over Constrained Native Color = Not Recognized by DimXpert

Sketch Dimensions Facilitate part creation, configurations, design tables Linked to construction geometry not present in finished part Aren t always consistent with methods used for manufacturing Don t always meet requirements necessary to support geometric tolerancing

DimXpert Dimensions Communicate part s functional requirements for assembly, manufacturing and inspection Always associated with manufacturing features Always associated with a tolerance Dimensions (basic) associated with geometric tolerances originate from and are oriented to the datum reference frame

Tolerance type and values created by Size Dimension and Auto Dimension Scheme

Chain Baseline

1. ADS (Automatic Dimensioning Scheme) and Geometric Tolerancing 2. ADS and Plus-Minus Tolerancing 3. ADS and Selected Features 4. ADS and the Wedge 5. ADS and Concentric Features 6. Feature Selector 7. Manual Tolerancing 8. More Feature Selector

Plus and Minus Geometric

Location Dimension Size Dimension

Intersect Plane Intersect Line Intersect Point Plane intersection between a cylinder and a cone Line intersection between a two planes Point intersection between a cylinder and a plane

Notes BOM Title Blocks DimXpert and Reference Dimension Support in 2D Drawings

Tolerance stack-up analysis is the study of dimension and tolerance schemes to determine potential form, fit, and function problems in parts and assemblies Included with SOLIDWORKS Professional and Premium What the permissible gap (G) between Part1 and Part4?

Assumes dimensions vary within the entire range of their tolerance zones and that the accumulation of tolerances will experience all possible variations G min = L 1 + L 2 + L 3 + L 4 + L n = L 1 + L 2 + L 3 + L 4 = 152.75 + (-60.75) + (-42) + (-50.5) = -0.5 Interference

Assumes dimensions vary randomly within a normal distribution (±3σ) centered about midpoint of the tolerance zone. G = G nominal ± T 1 2 + T 2 2 + T 32 T N 2 = 2 ± 0.25 2 + 0.75 2 + 1 2 + 0.5 2 = 2 ± 1.369 G min = 0.631, G max = 3.369 G nominal = 153-60 - 41-50 = 2

It is incorrect to think max worst case is when the parts are at their largest and min worst case is when they are at their smallest Part Nominal Assembly Worst-case Maximum Worst-case Minimum

Functional Requirement: D >= 39

Top Plate Angle Bracket Bushing

To reduce the tolerance stack by 0.8 (39 38.2) the tolerance of each dimension would have to be changed to ± 0.1 Before After

By increasing the width between the faces locating the two angle brackets by 1 mm the results for the minimum worst-case gap would be 39.2 (38.2 + 1) Before After

By adding a dimension between the planes which locate the axel supports and removing the 40 dimension on the right side of the part the tolerance stack between the planes is reduced from ± 1.1 to ± 0.3. As a result the new worst-case minimum dimension would be 39. Before Before After

http://blogs.solidworks.com/solidworksblog/2015/10/mbdimplementation-10-dos-and-10-donts-dont-hesitate-part-1.html

Create MBE Vision Plan Identify Data Needs Assess PMI Consumption