LibreCAD Lesson 2: Offset Circle — Diameter 6 to 8 mm

Learning outcome

Continue the 100 × 30 × 5 mm practice plate in 2D. Create an offset circle at drawing coordinates (15,35), then change that same circle from diameter 6 mm to 8 mm without moving its centre.

Before you start

Beginner lesson · 5:10 · English. Work on a separate copy of your Lesson 1 DXF and check millimetres. Keep the original plate drawing.

Step-by-step guide

1. Preserve and read the starter (00:25–00:40)
Open the saved plate drawing and keep a separate working copy. Check the 100 × 30 mm top view and the 5 mm front-view thickness.

2. Locate the centre (01:13)
Use drawing coordinates X = 15, Y = 35 for the circle centre. These are drawing coordinates in the offset top view, not a local (15,15) point in an unshifted plate.

3. Set the first diameter (01:38–02:24)
Create the circle with diameter 6 mm, equivalent to radius 3 mm. Use a true diametric measurement and preserve a D6 checkpoint.

4. Edit the same circle (03:04)
Change its diameter to 8 mm, equivalent to radius 4 mm. Keep the centre fixed at (15,35) and leave the plate dimensions unchanged. Do not add a second circle as a replacement for editing the existing one.

5. Compare the views (03:48)
Check the circle and its front-view representation against the video. This drawing represents a hole in 2D; it does not create a 3D cut.

6. Save, reopen and inspect (04:23)
Save a separate D8 DXF, reopen it and recheck centre coordinates, diameter and plate dimensions. Retain both D6 and D8 files.

Try it yourself

From a D6 copy, predict the radius for diameter 8 mm, then repeat the same-circle edit. Explain why the centre stays fixed while the radius changes from 3 to 4 mm.

Check your result

• D6 is Ø6 / R3; D8 is Ø8 / R4.
• The drawing centre remains (15,35).
• The represented plate remains 100 × 30 × 5 mm.
• Native DXF checkpoints reopen with the intended geometry.
• The exercise remains a 2D representation.

Common mistakes

Do not confuse radius with diameter, a diametric dimension with a linear distance, or drawing coordinates with local plate coordinates. A second circle does not demonstrate editing the original circle.