A laser cutter can basically do three things with text:
- Raster it
- Vector cut the outline
- Vector engrave the stroke
This instructable is about #3, engraving the characters with a single line. Why would you want to do this?
- Marking parts with a part number, etc. Faster than rastering.
- Labelling controls or connectors on a panel.
Why is this even a big deal? It should be easy. Unfortunately it's not. While CAD packages represent fonts as vector strokes, they don't make it easy to explode those strokes into lines. There is a complex workaround for one CAD package involving WMF files.
The process will be:
- Create drawing in CAD
- Replace text labels with exploded text from an online tool
- Export to Corel Draw / laser cutter
Begin with a CAD drawing of the panel. Include placeholder text for the engraved labels. The height of the placeholder text should be correct, however the width, font and style don't really matter as it will be replaced.
Step 1: Verify Placeholder Text
Text in CAD has an insertion point - one of nine choices: (top/mid/bottom) X (left/center/right).
Make sure your placeholder text is accurately placed with an appropriate insertion point. In this example the insertion point is "TC" (top center) accomplished by measuring down from the QUA (quadrant) of the circular hole. Why? We will use the placeholder's insertion point to locate the real text.
The picture shows a line from the insertion point of the placeholder text.
If you don't need precision, skip this step.
Step 2: Set Up Layers
In your CAD program, create at minimum these layers.
Step 3: Create and Import First Label
Go to http://wildsparx.com/textlines and create a label. You will download it as a DXF.
In CAD, use the INSERT command to insert it. INSERT will prompt you for the DXF filename. This time, just manually locate it near the corresponding placeholder text.
Decide if the label looks right.
Step 4: Adjust Label Parameters
In the picture, we've manually placed the test label near the placeholder. Comparing them:
- Height looks OK
- Characters are too close together
Go back to the textlines tool and adjust the kerning. Kerning controls the extra space between characters. Characters too close together will look bad, especially at smaller sizes where the laser
kerf becomes significant.
In this case a kerning setting of 0.18 looked good.
Step 5: Make and INSERT All the Labels
Put the placeholders on the OLDTEXT layer (using CHPROP). This will reduce confusion.
Erase the test label and INSERT final versions of both labels. Use the insertion point of the placeholders.
Put the new labels on the TEXTLINES layer.
When everything looks good erase the placeholders. You can try hiding the layer but it may get unhidden when imported into Corel Draw.
Step 6: Export the DXF and Cut
You probably know this step, but use DXFOUT to generate a DXF for Corel Draw import. Use the oldest ASCII DXF version available, in this case R12.
In the laser printer driver, map the RED color to an appropriate engraving setting so it won't cut all the way through.