TyGraphs - Creating a Lap Joint first created 06/01/12 - last modified 06/01/12 Page Author: Ty Harness

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How to add a lap joint in using the TyGraphs Software provided free for registered members.

All the patterns exported from the TH Sheet Metal applications are a continuous polylines in a DXF format.

From TyGraphs

Start a new drawing.

File -> Open (or import dxf) -> and browse for your pattern using the open dialog and select OK.

Select the pick tool from the tool bar and pick the pattern by left button clicking near the pattern

The pattern bounding box is highlighted to show which polyline has been selected.

Press the Right button and select Explode Object.

Pick the edge (line) where you want to add the lap joint.

Right button and choose Offset object and then enter the dimension required.

Figure 1 - Edge offset to create a lap joint

Press the space bar to escape out of the pick command.

Choose the line tool and the vertex snap. You can toggle the vertex snap by pressing v on the keyboard.

Insert the 2 small joining lines.

Figure 2 - Connect up the gap with snapped lines

Press the space bar to release the command

Choose the pick tool and select the unwanted line.

Right button and delete the line.

The drawing now consists of purely line elements to describe the pattern.

You can turn them back into a polyline by going to

Draw -> Polyline -> Convert line selection

Figure 3 - All the lines connected back into a Polyline

You can now re export the polyline as a DXF if you want to use it else where (such as your CAM software.)

You can also Save As in the TyGraphs file format if required.