Table of Contents
1.0 Purpose 1
2.0 Scope 1
3.0 Revision 1
4.0 Reference 2
5.0 Abbreviations/Definitions 2
6.0 Part Modeling 3
7.0 Assembly Modeling 4
8.0 Drawings 7
9.0 File Naming Conventions 9
10.0 System Maintenance 10
11.0 Appendix A: Drawing Samples 11
1.0 Purpose
This document defines the preferred practices for the use of SolidWorks mechanical design software.
2.0 Scope
The intent of this document is to outline modeling methods that have been found to work well in the <company name> environment as well as identify those that don’t. This document should be used in addition to good judgment based on experience with SolidWorks design software.
3.0 Revision
This is a new revision and should be read in its entirety.
4.0 Reference
4.1 WI-5-1-8 SolidWorks Workgroup Manager – User Procedures for specifics on custom property usage and general Windchill PDM interface information
4.2 \\Hydra\meteam\Standards\ OPTI_SWsettings.sldreg for importable SW settings (file locations, line weights etc).
4.3 Lombard, Matthew. SolidWorks 2007 Bible, Wiley Publishing, 2007.
4.4 ASME Y14.5 -1992, Dimensioning and Tolerancing
4.5 ASME Y14.41- 2003, Digital Product Definition Data Practices
5.0 Abbreviations/Definitions
FMT: Feature Manager Tree – The model structure of either a part or assembly file.
PDM: Product Data Management – PTC Windchill software used to manage company data.
6.0 Part Modeling
6.1 Approved Part Templates should be used.
6.2 All sketches must be fully defined.
6.3 All sketches and features must be error free.
6.4 It is preferable to use simple sketches and multiple features vs. a single complex sketch with a single feature. (i.e. a single sketch that contains the part profile, cuts, fillets, chamfers and holes is undesirable) This type of practice makes future edits of the part difficult and can actually negatively affect performance.
6.5 Feature creation should be as simple as possible. The practice of adding/removing material when a previous feature’s dimension could have been changed to achieve the same result should be avoided. (No FrankenModels). Renaming of features is not necessary, but is desirable where practical.
6.6 A minimal amount of dimensions should be used to define sketches. Sketch relations and construction geometry are the preferred method of ensuring design intent. If multiple dimensions are necessary that are intended to be the same value, the “link values” function should be used.
6.7 Make relationships to sketches rather than to faces or edges when possible (this is because faces and edges tend to lose references easily). Don’t make relations to tangent edges created by fillets (fillets are often moved, deleted or changed, which may upset your relations).
6.8 Use hole wizard to generate all holes. This is helpful in the assembly environment for patterning hardware as well as the drawing environment for hole callouts.
6.9 Use SolidWorks Weldment functionality for welded frames rather then creating an assembly with individual parts. Weldments of plates are to be modeled in a single part file as well, resulting in a multi-body part.
6.10 Material must be defined within the part file so an accurate assembly weight can be determined.
6.11 When making changes to a part (revisions) that involve editing sketches, deletion of sketch entities should be avoided. New sketch segments generate new faces and edges, thus turning dimensions brown in the drawing. If at all possible, sketch entities should not be deleted when making this type of change.
6.12 When generating a mirror component (Left Hand and Right Hand), the Insert>Mirror Part functionality should be used… generating a new part file that is driven by the parent part file. The mirror part should not be generated in the context of an assembly. Generating a mirror part as a configuration within the primary part is undesirable.
6.13 Don’t model things that don’t need to be modeled: for example knurling, threads, and connector pins.
6.14 When the part is completed, it should not have any suppressed features, unless the suppression is for the purpose of changes between configurations.
6.15 Configurations should be controlled using a design table. Files with only minor differences between configurations and/or files with only a couple configurations may not need to be controlled by a design table.
6.16 For components that require engraved or silk-screened text, the use of extruded text is NOT desirable. See Drawings section for preferred method.
6.17 Verification and Validation will need to occur on solid models that are given or intend to be given to manufactures. This validation is not indicating that the CAD model is suitable directly for CNC manufacturing. Additional work would be necessary to prepare the CAD model for CNC manufacturing (MMC adjustments etc). The model is simply a reference for the manufacture to use as they see fit. The drawing is still the contract document. This is not to be confused with Digital Product Description (see References and drawings section.) A note is to be added to form 4.4 (Drawing Checklist) and in PDM Meta-Data specifying that the model has been reviewed and approved for accuracy and conformance with the drawing. Do specify revision and iteration reviewed.
7.0 Assembly Modeling
7.1 Approved Assembly Templates should be used.
7.2 The first part inserted into an assembly should be a major component. It should be fixed to the origin of the assembly. There may be exceptions to this but there should be a good reason behind the deviation.
7.3 All components must be fully constrained with the exception of hardware. Hardware does NOT require a mate to “clock” it.
7.4 A folder should be created within the assembly model called “HARDWARE”. All of the hardware should be moved into this folder. This is so the checker can quickly inspect the assembly model looking for unconstrained components. Everything outside of the HARDWARE folder must be fully constrained.
7.5 Derived Component Patterns should be utilized as much as possible. Specifically for the insertion of hardware. This is to minimize the total number of mates in the assembly. Linear and circular patterns should only be used when a derived pattern cannot. Linear and circular patterns are not driven by part geometry and therefore must be manually updated if a hole pattern changes.
7.6 The preferred method of mating parts is to follow the “real world” logic of assembly. This means mating hole patterns with concentric mates. This is a form of design check. It also helps to ensure that hole patterns get updated appropriately because mates will fail in the assembly if patterns are not consistent.
7.7 The number of top level assembly mates should be kept below 300 due to processing capabilities. If an assembly is approaching this threshold, greater utilization of sub-assemblies should be considered.
7.8 Flexible sub-assemblies should be avoided. Use of flexible subassemblies will slow things down
7.9 In-Context Design should be used sparingly. It should only be used in cases where components will NOT be re-used in other designs.
7.9.1 Keep track of your in-context use. Order your parts so references only go up the tree. Good practice is that all in-context features are based off of the first part in the assembly. The use of skeleton parts or assembly layout sketches is even better.
7.9.2 If you feel you must remove external references from parts, at least use “Lock References” instead of “Break References”. This gives you the ability to change your mind later. There is no benefit in Breaking References. If good practices are followed, there isn’t a need to lock references.
7.9.3 An in-context part should NOT be initially created within the assembly (insert > component > new part… select plane). It should first be created as a standalone part, then added and mated within the assembly. Only then should in-context features be added. This is in an effort to minimize the amount of geometry that is controlled by the assembly. It also prevents the part geometry from “being off in space” within the part file (relative to the origin of the part). This practice results in a more robust in-context assembly.
7.10 Don’t mate to in-context features, component pattern instances or assembly features. Mating to these types of features can easily cause circular references within the assembly. Causing rebuild icons that won’t go away and drastically increasing rebuild times.
7.11 Don’t mate to features that are eliminated in a configuration.
7.12 Resolve all feature and mate conflicts / errors
7.13 Distance and Angle mates should be avoided if possible unless they specifically represent design intent. Preferred methods of achieving the same result are to create planes at the part level and using a coincident mate. Distance and angle mates sometimes flip in the assembly (specifically if the assembly is large). Coincident mates to planes created at the part level are more robust.
7.14 Use Display States instead of configurations for visualization only. Display States are much faster.
7.15 For the purposes of large assembly management, SpeedPak functionality should be utilized.
7.16 Due to Windchill PDM restraints, hardware inserted must be “all there or none there” (for a given hardware part number). It is acceptable to generate an assembly model with no hardware. The hardware part numbers will be manually entered into Windchill. However if it becomes necessary to insert a piece of hardware (for stackup or detailing purposes) every instance of that specific piece of hardware must be inserted. This is because the Windchill BOM is driven by the SolidWorks model and is un-editable once SolidWorks contains an instance of a part.
7.17 Due to Windchill PDM restraints, suppression of components is unacceptable (for completed designs). Windchill doesn’t support it (no error message, just freeze). This sometimes becomes a minor issue when creating multiple configurations for the purpose of showing assembly steps or components hidden for clarity (see use of Display States). In this situation, hide should be used rather than suppress.
8.0 Drawings
8.1 Approved Drawing Templates must be used.
8.2 Drawings will conform to appropriate ANSI/ASME standards, including ASME-Y14.5-1992 (Geometric Dimensioning and Tolerancing).
8.3 Title block information is driven from custom properties within the drawing file and/or custom property information in the model file.
8.4 Notes are placed on the sheet of the drawing (with the views, but locked to the sheet), not on the sheet format.
8.5 BOMs do not exist on the drawing. Instead a label, “SEE SEPARATE PARTS LIST” is placed in the lower right corner of the drawing. The separate parts list is the product structure located within the pdm system.
8.6 PDFs should be created on the appropriate sized sheet. They should not be scaled to fit an 8.5” x 11” sheet. SaveAs pdf appears to give better results than printing to pdf.
8.7 The below list of Line Thicknesses must be used for pdf generation and hardcopy print generation:
Printer Line Thickness
Thin: .005in
Normal: .010in
Thick: .014in
Thick(2): .020in
Thick(3): .028in
Thick(4): .039in
Thick(5): .055in
Thick(6): .078in
8.8 For components that require engraved or silk-screened text, the use of extruded text is NOT desirable. The preferred method is to use sketched text within the model and then overlay annotations in the drawing file. A 1:1 scale view is placed on the drawing. Within this view, the corners of the part are identified with cross hairs. A few holes can be identified with center marks. All edges are changed to the color white. A reference dimension is also placed on the view to ensure proper scaling when printed. See Appendix A 11.1 for example.
8.9 Installation drawings or any drawing that shows a reference structure or component shall follow the below guidelines. The reference structure’s model will conform to the proper naming convention. The component line font of the reference part shall be changed in all views to thin and solid. The component shall be placed on a new layer called GRAY. The layer shall be set up such that model edges are thin, solid, and a dark shade of gray. See Appendix A 11.2 for example.
8.10 On occasion the intended manufacturing method of a component will be to use the SolidWorks model directly (ex: stereo lithography, Selective Laser Sintering etc). Reference: ASME Y14.41-2003, Digital Product Definition Data Practices. In this situation a specific details are unnecessary but a drawing must be created regardless. It will contain an image, overall dimensions, critical dimensions, material, notes, etc.
Parts that are intended for this manufacturing method shall include a drawing with at least the following: See Appendix A 11.3 for example.
· Envelope dimensions
· Datum references
· Special feature information
· Tolerances
· Fully define/locate a select few features (e.g. holes) for the machinist to gain confidence in the program and setup.
· Material selection
· Finishes
· Special notes
· Boarder with Rev control, etc.
· A note containing the exact name of the file to be used for manufacture (including revision).
9.0 File Naming Conventions
9.1 Drawing Files: All drawing files will receive the OPTI part number only and no configuration dash number.
Drawing File Example: 1004389.SLDDRW
9.2 Single Configuration Part/Assembly Files: Part files are to be named with the OPTI part number including dash number.
Single Configuration Part File Example: 1004389-001.SLDPRT
9.3 Multi-Configuration Part/Assembly Files: Part files are to be named with the OPTI part number without a dash number. Configurations will be made using a design table where appropriate. Configuration names will be the complete part number (1004389-001, 1004389-002, etc).
Multi-Configuration Part File Example: 1004389.SLDPRT
9.4 OEM Part Files Modeled in Assemblies: This applies to OEM items such as zip-ties, hoses, and etc. that would be modeled specifically for an assembly for visual aid. These files are named first by the assembly “used-on” number followed by the OEM part number. The dash number for the assembly portion of the file name only needs be entered if it is specific to a certain configuration. A dash number can apply to the assembly configuration and/or OEM configuration.
OEM Part Files Modeled in an Assembly Example: 1005909_1002508-002.SLDPRT
9.5 Part Files such as Raw Stock: These files will be named with the assembly “used-on” number followed by a noun phrase describing what it is. This applies to anything that cannot be tied to an OEM document or drawing such as a weldment drawing that would only callout raw stock. This is the non-preferred (old) method to model a weldment therefore this filenaming is a rare occurrence. This method is more often used when a reference structure is required for an installation assembly.
Part File Examples: 1004486-001_bead1.sldprt or 1014552_GantryRef.sldprt
10.0 System Maintenance
10.1 The temp areas of your computer should be cleaned out regularly. Once a week should be ok. (C:\windows\temp, C:\documents and settings\<user name>\local settings\temp)
10.2 Know where SolidWorks puts backup and autorecover files, and clean these out when not needed (C:\documents and settings\<user name>\local settings\TempSWBackupDirectory). This location can be changed by going to tools>options>system options>backups.
When these areas become too full, Windows delays slightly when SolidWorks is trying to read or write to them, and functions can time out or crash.