AutoCAD Can’t Join Lines? | TutoCAD

Understanding the Issue: Why AutoCAD Can’t Join Lines

AutoCAD users often experience challenges when attempting to join lines and polylines, leading to frustration. This problem is frequently due to various factors, often related to the properties of the objects you are trying to connect.

Identifying the Causes

1. Elevation Differences:

   • One of the most common reasons for not being able to join lines is that they exist at different elevations. High precision in elevation data can be subtly causing the issue. To check this, use the UNITS command to set the precision to the maximum level. Examine the Properties palette, looking for the Start Z and End Z values. Adjusting elevations to be uniform will typically resolve the issue.

2. Small Gaps:

   • When two lines do not physically meet—due to a gap, even a minute one—AutoCAD will not be able to join them. You may need to zoom in closely to see these gaps.

3. Geometry Issues:

   • Lines might have segments that have zero length or share points but do not connect correctly due to complex geometry. Ensure that each segment has a distinct length.
4. Software Limitations:
   • Users of older AutoCAD versions might encounter limitations or bugs that prevent joining. Upgrading to AutoCAD 2025 can resolve many issues associated with working with polylines and lines.

Steps to Join Lines in AutoCAD

1. Select the Lines:

   • Start the command PEDIT (Polyline Edit) by typing it into the command line.
   • Choose the Multiple option to select all the lines you wish to join together.

2. Adjust Elevation:

   • If you suspect elevation differences might be causing the issue, check and make adjustments using the Properties window. Ensure that the Start Z and End Z values are the same for the lines.

3. Check for Gaps:

   • If lines are still not joining, use the Fuzz Distance parameter in the PEDIT command to specify a small range. This option allows AutoCAD to seamlessly bridge gaps between the endpoints of your selected lines.
4. Complete the Join:
   • After making any necessary adjustments, repeat the joining steps by selecting the lines and applying the Join option again within the PEDIT command.

Using Additional Tools

• OVERKILL Command:

  • To eliminate overlapping lines or redundant entities, utilize the OVERKILL command. This command suggests options to delete duplicate objects and optimize your drawing.
• TRIM and EXTEND:
  • If you’re working with Inventor or other design tools, using the Trim command can be a manual solution for bringing lines together. Hold the Shift key after selecting the lines you want to connect.

Frequently Asked Questions (FAQs)

1. What if my lines still won’t join after adjustments?

   • Double-check any hidden gaps and ensure no zero-length segments exist between the vertices. Also, consider using the OVERKILL command to clean up your drawing.

2. Can I adjust the precision settings in AutoCAD?

   • Yes, use the UNITS command within AutoCAD. Raise the precision settings to see finer details regarding the elevations and positions of your objects.
3. Are there limitations on line joining in earlier AutoCAD versions?
   • Yes, earlier versions may contain bugs or limitations that impact joining functions. Upgrading to AutoCAD 2025 is highly recommended for improved performance.