Coordinates

Exercise 16 – Coordinates

In this exercise we’ll explore three coordinate systems. Each one uses the same coordinates bar to enter the values.

Cartesian:           X = X axis distance, Y = Y Axis Distance

Cylindrical:         D = Distance       A = Angle

Mapping:            B = Bearing          L = Length

Direct:                / = Length Locked

By pressing the matching letter X, Y, D, A, B, L (and Z for 3D work) on your keyboard the cursor will move to the desired field and activate one of the coordinate systems. Let’s do that now.

  1. Press ‘X’ on your keyboard. The highlight will move to the X field ready to accept a value for the X direction.
  2. Press ‘Y’ on your keyboard and the highlight will move to the Y field ready to accept a value for the Y direction.
  3. Press ‘D’ on your keyboard and the coordinates system will change to cylindrical and await your input of a Distance value in what is now the D
  4. Press ‘A’ and the highlight jumps to the A field waiting for you to enter an Angle
  5. Now press ‘B’ to see the coordinates system change again to mapping mode and awaits the entry of a Bearing
  6. Press ‘L’ to see the highlight move to the, Length

You can ignore the ‘Z’ field at the moment as we’re not doing anything in 3D.

Did you notice the small letter ‘i’ next to those letters? – It indicates whether you’re in ‘incremental’ or ‘model’ coordinate mode.

If ‘i’ is showing, the values you enter are measured incrementally from (relative to) the last point.

If the ‘i’ is NOT showing then the values you enter will be measured from model zero which is where the origin of the Workplane currently resides.

Pressing i on the keyboard whilst a field is active will toggle between incremental and model coordinate mode for that coordinate field.

Pressing m on the keyboard whilst a field is active will toggle between incremental and model coordinates for all coordinate fields at once.

  1. Whilst one of the coordinate fields is selected press ‘i‘ on your keyboard and notice what happens. Press ‘i‘ again and notice the incremental indicator switches again.
  2. Now press ‘m’ and this time you will see the letter i appear and disappear for all fields, not just the highlighted one.

Incremental vs. Model

m = model coordinates measure from a single datum point, 0,0,0
i = incremental coordinates measure from the last position drawn.

/ Direct Distance

Press / (forward slash) followed by the distance, then click with your mouse in the direction desired for a fast way of inserting lines.
You can use the SHIFT key when you click to constrain the angle too.

In the next three exercises we’ll produce the same drawing three times using three coordinate methods, Cartesian, Cylindrical and Mapping.

The idea is to get an understanding of how each of them operates so you can apply the most appropriate method to your own design technique.

By doing this exercise you’ll also know when not to apply a particular method.

When you have completed the three methods then try using the Direct Distance / Length Lock method.

Exercise 17 – Cartesian (X,Y,Z)

Open the file in the Training folder called ‘Cool-Coordinates’. It should look like this.

A satellite image has been inserted and scaled to full 1:1 size. We’ve inserted three visual guides to the left of the drawing to indicate direction and angle depending on which coordinate system you’re using.

We’ll insert the outline of a building to be positioned in the vacant lot area ‘A’.

  1. From the Style Bar, select the Weight icon and select a heavy line weight such as 7 so it is easier to see, and then click OK.
  2. Select the Insert line command …and as per usual, look at the prompt. J
  3. Even though it may be difficult to see the cursor on the background image, carefully move your cursor over the yellow cross/point near the letter ‘A’ on the drawing and when you see a small square at your cursor click to snap the start of the line to this point…
    …and then let go of the mouse completely. Yes, take your hand OFF the mouse -He’ll be alright…you can come back to him later!
  4. Press X on your keyboard and look at the coordinate bar to check that the X field is highlighted. Don’t touch the mouse yet!
  5. Type 0 (zero) in the X field then press the Tab key to move the cursor to the next field.
  6. Type 20000 in the Y field, and then press Enter. We are currently working in millimetres so the values seem quite large!
  7. Now repeat the process above for the following X and Y values in the table below.
    Be sure to include the minus symbol for -negative values where shown. (Use the minus sign on your keyboard).

  1. Now grab the mouse and snap the end of the last line to the beginning of the first line at point A to form a closed outline of the proposed building.

Phew. That was a marathon!  For outlines containing many angled lines, the Cartesian method is NOT the preferred way. It is just plain hard work! This X and Y process works best when the lines follow the X or Y axis!

Let’s try a better method for this particular outline shape…

Exercise 18 – Cylindrical (D, A)

  1. Undo the lines you drew in the previous exercise back to the start of the drawing.
  2. Make sure the software is still ready to draw lines. Look at the prompt to check. If not then select the Insert Line command again.
  3. Snap to the point entity near ‘A’ to start the first line again (cursor should be a small square to indicate it has seen the point entity)
  4. Now then let go of the mouse!
  5. Press ‘D’ on your keyboard…and check the coordinates bar.

  6. Enter the distance for the first line by typing 20000 and then press the Tab key on the keyboard to move focus to the next field, the ‘A’ angle field.
  7. Next type the desired angle of the line, 90 and press Enter.

A line will be drawn at a length of 20000mm straight up the screen.

  1. Now repeat the process above for the following values:

  1. Now grab the mouse and snap the end of the last line to the beginning of the first line near point ‘A’ to form a closed outline of the proposed building, and you’re done.

Exercise 19 – Mapping (B, L)

We’ll repeat the same exercise a third time only this time we’ll use Bearing and Length values. This is much the same as the previous method except the angle is calculated clockwise with zero being in the 12 O’clock (North) position.

  1. Use the knowledge you’ve gained to redraw the shape using the Bearing and Length values in the table below type.

  1. Like the previous method use the mouse to snap the end of the last line to the beginning of the first line.

Beginners Tip

Print a copy of the PDF file below and keep nearby as a reference whilst learning.
Link to Coordinates Page (PDF) to be printed

Exercise 20 – Degrees# Minutes’ Seconds

Coordinates can be entered in various formats such as whole numbers, decimals, angles, bearings, Northings and Easting’s etc., let’s do one more drawing exercise using this same file, only this time we’ll draw the site boundary of one of the other lots, Lot B.

Architects, surveyors, landscape designers and many other professions will need to use this type of data entry.

  1. Zoom Window to area B, marked with the dotted yellow line.

  2. Select colour 5, line weight 5 and line style 5 before you start to draw.
  3. Select the Insert Line

We’ll start drawing from a fixed point that is 294.555 meters away from the Workplane origin in the X direction and 171.61 meters away from the Workplane origin in the Y direction.

  1. Press ‘X’ on the keyboard and then press ‘m’ to tell the software you’re about to enter model The letter ‘i’ should not be visible in the coordinate bar.
  2. Enter 294555 in the X field (we’re working in mm) and then press Tab.
  3. Enter 171610 in the Y field and press

The start of the first boundary line is now in place.

  1. Press B on the keyboard to invoke the bearing field.

We are about to enter a bearing value of 66 degrees, 47 minutes and 16 seconds. To do this we must enter it in the following format where      # = degrees     and     = minutes

  1. Without any spaces enter exactly 66#4716   and press Tab to move to the length field.

The software may convert the value you entered to a decimal angle value and be ready to accept the desired length value.

  1. Enter the length of 72256   and press Enter

Repeat for all the boundary line values (You’ve already drawn line 1 so no need to re-enter it)

Select and Delete the protractor guides to reduce the file size and then use File, Save-as to save the completed drawing in your desired folder as ‘My Training Site’.

180°

Angles displayed on survey drawings may be 180° too great or too little, due to conventions used by surveyors, so check the angles against the protractor and adjust as required by either adding or subtracting 180 from the angle shown on the plan to get a sensible and expected result.

Surveyors

You can use Bearings expressed in full decimal value; degrees, minutes and seconds; or Northings & Eastings (NSEW) e.g. N30, N30W, E30, E-30.

Direct Calculation Data Entry

For the technically minded, rather than use the calculator you can also enter a mathematical expression in an edit field.  Simply type an expression rather than a value.

E.g. (12+3)*65.2

Press the Tab key to see the result of the calculation before pressing OK to accept it.

See the manual for a list of mathematical expressions and functions you can use in numeric fields.

Note: You can use these in any dialog box numeric entry field, not just the coordinate’s bar.

Padlock Coordinates

The padlocks lock the current coordinate value and assist in drawing or editing in certain conditions.

Clicking on a padlock will toggle between a locked and unlocked state. Pressing ‘P’ on the keyboard whilst the field is active will also lock and unlock the padlock.

Perhaps the best use of the padlock is when you want to draw lines at multiples of a set distance but use your mouse to indicate direction.

Or padlock an angle value to force your movements to be in multiples of that angle.

In a similar way to the Shift key, the padlock allows the user to constrain and control movement, but when a Padlock is active the Shift Key works to temporarily unlock the constraints of the padlock.

 

When working in 3D, locking the Z value will force all lines to be drawn at the specified Z height.

Remember to un-padlock your coordinates when you have finished.