Engineering Drawing Standards

The design artifact section will largely consist of engineering drawings and their associated CAE files. Professional standards for engineering drawings should be followed. Many companies have drawing standards they want all employees to following. This section describes the drawing standards for Capstone. Note that in some cases sponsors may express the desire that teams follow the sponsoring company's standards. If they do, please follow the sponsor standards, and let the Capstone office know you are doing so. In all other cases, please follow the Capstone standards as described below.

Capstone Engineering Drawing Standards

Use B-size (11×17“) drawing sheets. These can be laser printed and have over four times the effective drawing area once a title block has been added. A-size (8.5×11” letter) sheets are too small, and anything larger than B-size is difficult to handle. If you have a need for something larger than B-size, talk with the Capstone office. Note: Do not use an A-size sheet without specific permission from the Capstone instructors. You will be asked to redo the drawings as B-size, and we don't want to make extra work.
The title block should have, at a minimum, the part name, drawing number, revision, drawn by, checked by, material, default tolerances, type of projection, unit systems, and scale. All elements in the title block should be filled out.
The bill of materials (BOM) for an assembly drawing should be immediately above the title block, with item numbers increasing upwards.
The revision history should be in the upper right of the drawing, with later revisions going down. The revision history should be present in all drawings, even if it is the initial release.
Circuit schematics should include types, values, tolerances, and units for all passive components. Circuit board layouts should include a note for conductor thickness and board type.
Assembly drawings and pictorial views (such as isometric views) should have hidden lines removed.
Orthographic views in part drawings should show hidden lines in most cases. Section views do not show hidden lines.
The most descriptive view should generally be chosen for the front view. If there is an obvious top to the object, the top should be selected for the top view. Select views to minimize the number of hidden lines. By convention, the preferred views are front, top, and right.

Dimensioning Standards

Here are a few dimensioning standards that will help you make professional-quality drawings.

Place dimensions so they are easily understood and do not interfere with the drawing.
Fully dimension each part, but do not overdimension. If there are two different dimensions that apply to a particular measurement, one should be indicated as a reference dimension with parentheses or the notation “REF”.
Indicate the dimension units in the title block, rather than on the dimension.
Inch dimensions do not have a leading zero before the decimal point. Metric dimensions do.
Use the proper number of significant figures for the desired implicit tolerance.
Use consistent dimensioning orientation (aligned or unidirectional).
Dimensions closest to the part should be 3/8“ away from the part. Successive rows of dimensions should be spaced by 1/4”. Dimension text should be 1/8“ high.
Dimensions should be placed outside orthographic views.
Dimensions should generally be placed between adjacent views.
Dimension lines should not cross, and should not cross part lines or extension lines.
Extension lines should have a 1/16” gap between the feature being dimensioned and the extension line. Extension lines may cross part lines.
Extension lines should not coincide with part lines.
You may use either baseline or conventional dimensioning, but be consistent.
Dimension to visible lines, not hidden lines.
Dimension in views where the feature has its true size and shape.
Dimension in views where the feature is most clearly shown.
Angular dimension lines should point to extension lines, not part feature lines.
Holes should be dimensioned in views where they show as circles. They should use the diameter symbol before the dimension or the notation “DIA” after the dimension. The location dimensions should come from the centerline of the circle.
Cylinders should be dimensioned in views where they show as rectangles. They should use the diameter symbol before the dimension or the notation “DIA” after the dimension.
Objects with rounded ends (not rounded corners) should be dimensioned using the centerline of the end as an extension line, and with a radius dimension on the end (the dimension is preceded by “R”).
When there are multiple identical features, dimension only one feature and indicate the number of features to which the dimension applies.
Rounds and fillets should be dimensioned by radius.
Chamfers may be dimensioned by horizontal and vertical distances or horizontal distance and an angle.
Hole depth should be specified for any non-through holes.
Counterbored holes require a counterbore depth specification. Spotfaced holes have only a spotface diameter.
Countersunk holes should be specified with a countersink diameter and angle.
Use proper geometric tolerancing standards when applying geometric tolerances. Description of these standards is beyond the scope of this list.

Drawing Checklists

A drawing checklist to help you check your drawings for quality is available on Box (pdf). As you check a drawing, use the checklist to help you ensure the drawing is understandable.