Skip to content

Projection of a Line — VektorCAD Tutorial

This exercise guides you through drawing the projections of a straight line using VektorCAD. You will construct the XY reference line, locate the endpoints based on their distances from HP/VP, obtain initial projections, then rotate to satisfy both given inclinations. Use Normal thickness for construction/projection/dimension lines and Thick for the final views of the line.

Problem Statement

Draw the projections of a line AB of true length 80 mm.
Endpoint A is 20 mm above HP and 25 mm in front of VP. The line is inclined at θ = 35° to HP and φ = 45° to VP. Show the front view ((a'b')) and top view ((ab)), and annotate the given distances and true length.

Given - True length |AB| = 80 mm
- Point A: 20 mm above HP → (a') is 20 mm above XY
- Point A: 25 mm in front of VP → (a) is 25 mm below XY
- Inclinations: θ = 35° to HP, φ = 45° to VP

Objective

- Draw XY, projectors, a', a, intermediate projections, and the final views of the line.  
- Use VektorCAD commands: xyline, ucs, point, line, arc, dimlin, dimalign, text.  
- Thickness: Normal for XY, projectors, and dimensions; Thick for final ab and a'b'.  
- Turn Entity Snap ON throughout.

Step‑by‑Step

1) Prepare Drafting Settings

  1. Set Line Thickness → Normal
  2. Select Normal from the thickness options (Thin / Normal / Thick).

  3. Use Normal for XY, projectors, and construction lines.
    Normal Thickness

  4. Enable Snaps

  5. Turn Snap ON from the status bar.

  6. Turn Entity Snap ON for accurate intersections.
    Snap ON

  7. (Optional) Toggle Ortho ON to keep XY and projectors strictly horizontal/vertical.

2) Draw the XY Reference Line

  1. From the Line dropdown, click XY Line.
  2. Pick two points horizontally to draw XY (e.g., ~180 mm).
  3. Move the UCS to one endpoint of XY:
  4. Click UCS, hover over XY until the endpoint snap glyph appears, then click.
  5. The UCS origin is now fixed at one end of XY.

XY Line

3) Locate Endpoint A in Both Views

We will place a (top view) and a′ (front view) aligned vertically with the XY reference.

  1. Draw projector through a

  2. Run Line, snap to XY, and draw a short vertical (Normal thickness).

  3. Mark a (Top View)

  4. Run Point → type 0,-25 → places a 25 mm below XY (in front of VP).

  5. Mark a′ (Front View)

  6. Run Point → type 0,20 → places a′ 20 mm above XY (above HP).

  7. Label Points

  8. Use Text to label the lower point as a and the upper point as a′.

Point a and a′

The projector ensures that a and a′ are vertically aligned (same generator).

4) Draw Locus Lines

  1. Turn Ortho ON from the status bar.
  2. From point a′, draw a horizontal line.
  3. From point a, draw another horizontal line.
  4. These are the locus lines.
  5. Turn Ortho OFF when done.

Locus Lines

5) First Inclination — Line Inclined to HP (θ = 35°), Parallel to VP

We construct an auxiliary front view with true length at 35°.

  1. From the toolbar, click Line.
  2. Click point a′ as the start point.
  3. In the command prompt, type @80<35 → draws a line of 80 mm at 35° above XY.
  4. Mark the endpoint as b1′.
  5. This line a′b1′ is the auxiliary front view (Normal thickness).
  6. Use Copy to transfer the locus line from a′ to pass through b1′.

Auxiliary a′b1′

6) Second Inclination — Line Inclined to VP (φ = 45°)

Now construct an auxiliary top view at 45°.

  1. From the toolbar, click Line.
  2. Click point a as the start point.
  3. In the command prompt, type @80<-45 → draws a line of 80 mm at 45° below XY.
  4. Mark the endpoint as b2.
  5. This line ab2 is the auxiliary top view (Normal thickness).
  6. Use Copy to transfer the locus line from a to pass through b2.

Auxiliary ab2

7) Obtain the Final Top View

  1. From b1′, draw a vertical projector down to meet the locus line through a.
  2. Mark this intersection as b1.
  3. From the Arc dropdown, choose Start, Center, End.
  4. Start point: select b1.
  5. Center point: select a.
  6. In the command prompt, choose Clockwise.
  7. Drag the arc until it meets the locus at b2, then click.
  8. Mark the intersection as b.
  9. Change thickness to Thick.
  10. Draw the final line from a to b.

Top View

8) Obtain the Final Front View

Repeat the above process with the auxiliary top view to locate b′ and draw the line a′b′.

Front View

9) Dimensions and Labels

  1. Switch back to Normal thickness for dimensions.
  2. Add given distances from XY:
  3. dimlin XY → a′ = 20 mm.
  4. dimlin XY → a = 25 mm.
  5. Add other required dimensions for completeness.

Dimensions

Result Checklist

  • XY drawn (Normal).
  • Entity Snap ON throughout.
  • A 25 mm below XY; A' 20 mm above XY.
  • Auxiliary: A'B'₁ at 35°, A–B₁ projected (Normal).
  • Rotation: A–B₂ makes 45° with XY in top view (Normal), arc used with radius |A–B₁|.
  • Final views: A–B₂ and A'–B'₂ drawn in Thick.
  • Dimensions: 20 mm and 25 mm from XY via dimlin; true length via dimalign.
  • Labels: A, A', B, B', θ, φ via text.

Variations (practice)

  • Change only one inclination (e.g., θ = 0°, φ = 40° → line parallel to HP, inclined to VP).
  • Swap the order: first assume φ, then rotate in front view to impose θ.
  • Move the UCS to different working points (ucs) to make typed inputs faster.

Commands Recap

  • xyline — draw XY reference line (Normal).
  • Thickness — Normal for XY/projectors/dimensions; Thick for final AB and A'B'.
  • Entity Snap — keep ON for precise endpoints and intersections.
  • ucs — reposition origin near work area or on the projector.
  • point — mark A, A', and intermediate B points as needed.
  • line — draw projectors, auxiliary, and final segments.
  • arc — rotate top view about A to match φ while keeping radius |AB|.
  • dimlin — linear dimensions from XY to A/A'.
  • dimalign — aligned dimension for true length or slanted segments.
  • text — labels for points, angles, and notes.

You’ve completed the projection of a line using auxiliary views and rotation to satisfy both θ and φ, with final views clearly emphasized using Thick line weight.