ENGR1304: Chapter 6: pg 215, Dimensioning

Interesting article for the day:
http://www.pri.org/stories/2012-02-23/new-clues-emerge-centuries-old-swedish-shipwreck

"Vasa set sail on her maiden voyage on August 10, 1628. At the time, she was the most powerfully armed warship in the world, with 64 bronze cannons.
Twenty minutes into her journey, the ship was hit by two strong winds. It heeled to port, water gushed in, and the ship sank less than a mile into the journey.

Thirty people died.
"We have, over the last three years, measured every single piece of the wood in the ship," says Hocker. "If we want to understand how the ship was built, that's what it takes."
Hocker's meticulous measurements paid off. They gave him fresh insight into what made the Vasa unstable.
For one thing, the ship was asymmetrical, more so than most ships of the day.

Why was the ship so lopsided?
While examining the ship, Hocker discovered four rulers the workmen had used. Those rulers were based on different standards of measurement at the time.
Two were in Swedish feet, which were divided into twelve inches. The other two were in Amsterdam feet, which had eleven inches in a foot. So each carpenter had used his own system of measurement.
"When somebody tells him, make that thing four inches thick, his four inches is not going to be the same as the next guy's four inches," says Hocker. "And you can see those variations in the timbers, as well."

Moral of the story, it pays to pay attention to your units, measure and create everything as exactly as you can! (Warning: If your original drawings were not constructed exactly, it is going to show up when you start trying to dimension everything.)

Skim through chapter 6

Clarity:

Avoid clutter, use the minimum number of dimensions.
Dimensions should not overlap or interfere with drawn object.
Units are provided in title block, not in drawing.
Use consistent font and spacing
Place dimensions outside of views rather than in the drawing object itself.
Place dimensions between views
Do not dimension to hidden lines or T joints.
Use extension lines for angled features.
Dimensions are drawn with thin, dark lines (0.25mm)

Do your dimensioning in Layout space (so you don't have to reformat all your text sizes later)

Create a Layout:
Click on "Model" change to "Paper"

Notice the new Layout tabs in the lower left hand corner.

Click from "Paper" to "Model" again, and turn your grid off:

In a layout tab, experiment with Paper and Model space.

Draw something while it says "Paper" (like a circle)

Now, switch to Model space, and use the scroll on your mouse to zoom in and out. You will notice that the circle stays the same size, while the model space drawings zoom in and out.

Think of "Paper" space like a transparent layer on top of Model space.

Your title block and page borders will always be in paper space.

Insert your dimensions in model space.
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Create something in model space that will allow you to explore all of the dimension tools. Include a circle, arc, slanting line, etc.

Stretch out your drawing area to match the printable area.

Switch from paper→Model
Zoom → All
Resize drawing to fit nicely on paper, with extra room to add dimensions, by setting the scale factor. (Note, don't just zoom in to some random value, choose a standard scaling ratio)

create a new dimension layer.

Set your dim styles: type "DIMSTYLE" into the command line

Click "modify"

Set your precision to 0.00

Set your text height, and select and "Aligned with dimension line"
* note: You might have to play around with your text height a little to get it to match your scaling factor.

Set all your line types to "By Layer"

Choose "Set Current" to apply settings to dims.

Work on a layer in model space
If paperspace is selected instead of model space, your dims will not be attached to your object - ie - they will not resize, move, or show up in your model space)

Open up your Annotate tab, and have a look around.

DIMLINEAR - for horizontal and vertical measurements.

Use options in [the square brackets] to rotate text etc.. (you should have set this up already in your dim styles, but if you need to change something...) Just watch your command line every step of the way!!

You can also select a dimension → right click on the dimension→ select properties → then modify precision, text size, etc.

DIMRADIUS,
DIMDIAMETER: Measures the radius or diameter of a selected circle or arc and displays the dimension text with a radius or diameter symbol in front of it. You can use grips to reposition the resulting dimension.

DIMARC: Arc length dimensions measure the distance along an arc or polyline arc segment. The extension lines of an arc length dimension can be orthogonal or radial. An arc symbol is displayed either above or preceding the dimension text.

DIMALIGNED: for slanting lines (4.24)

DIMANGULAR: Measures the angle between selected geometric objects.

DIMCENTER:
Creates the center mark of circles and arcs.

DIMORDINATE: (X,Y) (15, 12.5)

UCS - User Coordinate System. Define where (0,0) is on your object, then use DIMORDINATE to measure points from your UCS

DIMBASELINE:
First, select dimlinear, dimangular, etc.as your baseline, then add additional dimensions.

DIMCONTINUE
Automatically continues creating additional dimensions from the last linear, angular, or ordinate dimension created, or from a selected extension line. The dimension lines are lined up automatically.