Layer assignment standards vary in importance from company to company. It matters more that there is a standard in place (that is used consistently) than what specific layer is used for what. Just as (or more)important is layer catagorization. It is very frustrating to receive a file from a vendor who uses layer standardization with no catagories listed.
At my day job, the layering convention is pretty complex, but thats what the customer wants...so I'll skip it.
At the night job, its pretty simple, layer 1 is the solid, 3 is for sketches, 4 is for datum planes, 9 is waved geometry, and 10 is reference components. That applies to simple models. Anything more complex, the sketches, etc., get spread out, usually on 20, 30, 40, so you have a range of 10 for various features. For an assembly I like, find no. 1 goes on layer 1, 2 on layer 2, etc., just so its easy when using visible in view on the drawing.
-Dave
Everything should be designed as simple as possible, but not simpler.
Our assembly files are much as Gunman posted; item 1 on layer 1, etc.
Out standards are pretty open other than the above, and we are currently in the process of adding and expanding some of the listed catagories to allow for ASME 14.41. If we need more layers for something, we add them, as long as the CATAGORY is defined. We don't have a grip license, and are not concerned with automated routines which may require stricter standards. Our main concern is that someone unfamiliar with the file should be able to easily navigate and find what they need.
1 - Solid, Part
2 - Wireframe, Part
3 - Centerline, Part
4 - Theoretical
5 - Section
6 - Developmental
7 - Mate
8 - Criteria
253, 254 - Drawing Format & Annotation
Categories:
SOLID: Solids and sheet bodies required to define the part.
WIREFRAME: Lines and curves required to define the part that is not defined by the solid(s). Wireframe extracted from a solid is not supported by the standard.
CENTERLINE: Lines and curves used as centerlines as required for sweeps and extruded solids, such as pipes, etc.
THEORETICAL: Lines and curves used as theoretical intersectionsas required for drawing purposes.
SECTION: Sections shown to define material thickness and part development when used in a non-drawing file.
DEVELOPMENTAL: All geometry types used to develop the part,
i.e. sketches, smart curves, trimmed sheet bodies, swept curves, datum planes, etc.
MATE: Datum planes, datum axes and saved coordinate systems and any other geometry (i.e. points) used for mating conditions.
What most people end up moving their development to layer 6 rather adding layers to the development category. Which makes it harder to modify things down the road.
1-199 ........ Any solid model including primitive bodies, swept from curves or sketches and sewn solids created from complex free-form bodies.
200 ........... Reference sets for assemblies that are different when after assembly such as a loaded spring.
201-229 .... Reference geometry consisting of sketch curves, wire-frame geometry used to extrude or sweep solid bodies or free-form sheet bodies and datum planes or axes.
230-239 .... Preparations for FEA, CMM, N/C, mold flow
240-246 .... Dimensions, Notes, Labels & GD&T
247-249 .... Customer Borders
250 ........... Title block text,Formats, KPC
251 ........... Revision Column Text
252-253..... New revision columns: After the revisions have gone to the bottom of the page.
254 ........... Revision Block Points to align lines with pattern.
255 ........... Translation data received Models shall have the layers tracked by layer categories.
In assemblies, as mentioned above Item #1 is layer #1, Item #2 is layer #2, etc...
GM also allows for user-defined categories, which can exist on any layer other than those listed above. The only catch is that the category name must begin with an underscore; something like _UPPER MOLD.
Yes, a seed file is a good way to go. Edit it as you would any other file. It's purpose is to make it easier to create drawings with the same initial standards.
From my point of work, there are two solutions:
1. When You work with large number of same type objects (solid bodies, sketches, curves...), put them on diferent layers, but name layers by object name. for example:
L1 rivets
L2 spoiler
L3 ...
L10 screw M5
L11 screw M8
L12 ...
2. ewerything You read up on this forum page.
