VIBV Drafting Procedures
VIBV staff consists of CAD operators, quality control managers, architects, and engineers. Each is a highly skilled user of AutoCAD, SolidWorks, Inventor, and work on drawings within their area of technical expertise. Our staff handles 100% of all CAD drafting and quality control. We provide 2D drafting and 3D modeling services using AutoCAD, SolidWorks, and Inventor software as outlined below:
1. Creating a New Project
- We create a new project once we receive your drawings and VIBV order form. Acceptable original drawing formats include TIF/PDF/JPG/GIF files, photos, AutoCAD DWG background files, paper, mylar, and blueprints.
- Our staff indexes and manages your drawings using Microsoft Project, which allows us to monitor progress at each stage of the conversion process.
- Our in-house architects and engineers review your original drawings along with any special requirements required for your project. Special requirements can include anything from layering guidelines to file naming conventions. If need be, a technical staff representative will get in touch with you to clarify details before we get started.
- Next, we will assign a CAD operator to handle your project. The operator will receive a full description of your project, including detailed instructions and special requirements. When selecting a specific CAD operator, we take into account the drawing content (architectural, mechanical, electrical, etc) and sheet complexity.
- At this time, you will receive an email confirmation that indicates the project start date, scheduled completion date, number of sheets to be converted, unit price per sheet and total project cost.
2. Redrawing the Sheet
- The next step is to redraw the original drawing to create a 2D AutoCAD, or 3D SolidWorks, or 3D Inventor model. The dimensions shown on your original drawings are used by the CAD operator to develop the CAD file.
- If the original drawing does not contain dimensions, the CAD operator will manually scale the drawing instead. Each entity will be drafted by manually scaling the bearings, distances, and coordinates on the drawing.
- The CAD operator will draw each entity on the proper CAD layer. Various layering standards are available such as the AEC, Tri-Services, AIA, Custom, or LITE layers. If you supplied custom blocks, the operator will incorporate them into the drawing at this stage.
- The resulting CAD file will be a SolidWorks (SLDDRW), AutoCAD (DWG), or Inventor (IDW) file that is:
- Dimensionally accurate
3. Level 1 Quality Control (QC)
- Level 1 QC is handled by the CAD operator. He/she must now re-check all line work, dimensions, layering, text, spelling, title blocks, xrefs, etc to ensure that the new CAD file matches the original drawing exactly.
4. Level 2 Quality Control (QC)
- Level 2 QC now moves to the CAD manager for an accuracy check. At Level 2 QC, the CAD manager will also verify the line work, dimensions, layering, text, spelling, title block, xrefs, etc of the CAD file for accuracy by comparing it to the original document.
- The CAD manager will carefully note any errors or omissions.
- If any trouble spots are found, the manager will return the CAD file to the operator to correct the problems.
5. Level 3 Quality Control (QC)
- Level 3 QC is a thorough 3rd review of the corrected CAD file to ensure all issues have been resolved. This review is also done by the CAD manager
- The file will only move on when 100% accuracy has been achieved.
6. Level 4 Quality Control (QC)
- Level 4 QC requires only a visual comparison between the new CAD file and the original drawing.
- The AutoCAD DWG, SolidWorks SLDDRW, or Inventor IDW file is exported to PDF format. Both color and black/white PDF files are generated.
- The appropriate color table files for plotting are attached to the project.
7. Transferring the Files
- Now it’s time for the completed files to be transferred electronically to the customer. The files are zipped for transmittal via email, Dropbox, FTP, Hightail, or CD-ROM.
- Upon completion, VIBV automatically archives all electronic files in case they are needed in the future. However, you can also request that the files be destroyed. We also honor requests to destroy the original hardcopies if provided.
8. Creating Backups
- VIBV backs up all converted files daily. We will retrieve a past project for you on request.
- Your project backup includes:
- Custom profile data
- Project profile standards
- TIF images of original drawings
- Final converted CAD files
- Exported PDF files
- Color table plot files (ctb)
Custom Profile Data
The majority of our work is from existing customers for their new and on-going projects. We have worked with many of our customers for 10+ years. In order to maintain consistency for each customer, VIBV generates a unique “customer profile.” This way, we’re able to maintain a standardized setup (fonts, titleblocks, layering, blocks, templates) for each new project. Whether you have concurrent or successive projects, the customer profile makes it easy to maintain uniformity.
We also can create separate “project profiles” when you have different requirements for each project.
For large projects we recommend starting with a sample conversion. Include your specifications for layering, blocks, fonts, etc. VIBV will prepare the sample file in 1 or 2 days and provide it to you for comments. You may add redline markups/changes and we will update the file. Once approved, this CAD sample will be used as the “template” for the remaining drawings in your project.
AIA Layering Standards
CAD layering standards are essential to seamlessly share graphic information data throughout the architecture, engineering, and construction industry. CAD layering and guidelines help users manage graphic information in their CAD building files.
There are many different layering standards and guidelines available for CAD drafting projects. Today, most CAD users rely on the CAD layer standards developed by the American Institute of Architects (AIA). Given its widespread use, VIBV also uses the AIA CAD layering standards as a default unless the client specifically opts for a different CAD layering standard.
CAD layers are divided into major groups and then subdivided into minor groups, each of which represents a layer in the converted CAD file. The CAD operator will label each layer with a simple abbreviation that remains consistent throughout the project(s). Major AIA CAD layer groups include:
A – Architectural
C – Civil
E – Electrical
F – Fire Protection
G – General
H – Hazardous Materials
I – Interiors
L – Landscaping
M – Mechanical
P – Plumbing
Q – Equipment
R – Resource
S – Structural
T – Telecommunications
X – Other Disciplines
Z – Contractor Shop Drawing
The colors for each layer should be consistent and all objects shall be drawn in color BYLAYER. This means that all objects assigned to a specific layer should be the same color. Occasionally, the need to create a new layer can arise in cases when custom defined layers or AIA layering standards are not available. Typically, any unused drawing layers should be purged from the converted CAD file.
For more information about the AIA CAD Layer Standards, please contact the Task Force for AIA CAD Layers at the following address:
Task Force on CAD Layer Guidelines
C/o The American Institute of Architects
1735 New York Avenue, NW
Washington, DC 20006
CAD Tools: Symbols, Blocks, Attributes
There are other tools that help in the organization of CAD entities. They include symbol libraries, blocks and attributes. These tools allow you to export CAD data to reports or Excel spreadsheets. They also let viewers count specific object symbols, such as parts; or count attributes, such as room numbers or areas for use by space management applications.
VIBV is ready to accommodate our client’s needs. We are happy to incorporate predefined symbol libraries, attributes, or blocks into the final CAD files. While these tools are not absolutely necessary, they are helpful by giving the user control and flexibility over the final CAD data.
Understanding Conversion Rules of Thumb
What happens if there are ambiguities, such as unclear data or missing dimensions, on a plan or drawing? For these situations “rules of thumb” are designed to resolve conflicts and enable uniformity of such information. Such rules of thumb are ideal for handling a number of issues and will point the way to a resolution.
Dealing with Undimensioned Drawings
When we receive drawings that do not have dimensions (or with fewer than 20%), our CAD conversion technique changes somewhat. Our CAD operators must manually scale each of the entities on the drawing. There are often 1 or 2 check points on the drawing that we can use to verify the manually scaled dimensions. These check points can be a scale bar, or an overall building dimension, or a commercial interior door width of 36″. The overall accuracy of the converted CAD file is very high and is reliably within 1%.
Unclear Dimensions or Text on Original Documents - IMPORTANT
Older as-built original drawings can contain information such as dimensions or text that are unclear or difficult to interpret. For these situations, the CAD operator will insert a “red box” as a flag on the README layer in the CAD file. The red box is a flag that displays the unclear data. You can then quickly zoom into the flagged area and make any necessary modifications. The “README” layer also goes through four levels of QC and will remain after Level 4 QC only in cases where the data was too unclear on the original sheets to convert.
Handling Dimensional Conflicts
Occasionally a dimension listed on the original drawing will conflict with the dimension scaled by the CAD operator. In this case, the dimension listed on the original document is maintained as the default. The dimension that was scaled by the CAD operator is added in RED on the “README” layer. Each dimensional conflict is shown in RED as a flag that should to be reviewed by the customer.
Different customers use CAD documents for many different reasons. Organizations often reuse their drawings for multiple purposes. In order to do so, they must first create a set of internal guidelines so that each document remains consistent with the others. This ensures seamless communication. It allows anyone in the organization (or even third-party contractors) to read CAD documents no matter where they are or what software application they’re using. Maintaining consistent standards also allows for the automatic searching and indexing of large numbers of files.
Over the years, VIBV has used many different types of CAD conversion guidelines. Based on our experience, we recommend six standards. You can choose one or all six as inspiration for developing your own in-house standards.
1. Title block:
Each sheet should maintain consistent title blocks, logos, and sheet borders. Each sheet size (A, B, C, D, E, F) should have its own title block template.
2. Model space:
Ideally, you should draw all document entities, dimensions, symbols, notes, etc. in Model Space.
Consistency often requires a set of present variables.
4. File Name – Drawing Number
You should be able to easily identify a specific drawing or building. This requires good file naming conventions. Ideally, the saved file name will contain a combination of the sheet number and the building name or number. It’s also important to add each document to an electronic index immediately after conversion. That allows for easy access and cross-referencing. A good filename convention may look something like this:
E = Drawing Type (such as E = Electrical)
JH = Building number/name (such as Johnson Hall)
0101 = Drawing sequence number (sheet number)
01 = Revision number or letter
5. Style Conventions
Text should also be standardized between documents, as should dimensions, and linetype styles. Fonts such as ROMANS and ROMAND are standard. It is also good to define the text height ahead of time. The text width, on the other hand, should remain flexible. That is because the width may change depending on the specific contents of each sheet, particularly if a sheet is unusually crowded. A text style may look something like this:
08 = Width factor = 0.8 = width of letter
ROMANS = Font
15 = Oblique angle (omitted when set to 0)
Many documents contain repetitive entities. Blocks are used to represent such objects. It is important that the blocks remain consistent throughout documents and even projects, if necessary. If you use an “X” to define a part in one drawing, then every drawing should mark parts with an “X.” Every employee, contractor, and consultant should also know how to interpret the symbols.
In order to ensure consistency and make interpretation easier, VIBV recommends creating a block legend that defines each and every block used. The operator should create the blocks with Layer 0 activated. They should then insert the block into the correct layer in the drawing. After inserting the block, the operator should then re-scale it to match the dimensions of the current drawing. Finally, it’s important to list all blocks in the drawing index and remove any unreferenced blocks from the drawing.
Clients often use or display their CAD documents on non-CAD software applications. Not only that, but different people may need to use the drawings for different purposes. An architect may need easy access to facility data so they can quickly find the square footage of a particular area. A structural engineer, on the other hand, may need to locate and identify the cross-sectional area of a beam.
Adding polygon layers helps solve the problem. By drawing a closed polygon over the top of each room and then over the entire building, the CAD operator is able to export precise data, including perimeter, room area, or location of an object. Clients can then transfer the information to other software applications.
When defining polygons, it’s important to rely on consistent standards.