How to Make Good Part Drawings for Abrasive Waterjets
One of the great things about computer-controlled waterjet systems is that you can draw a part on your computer, or even import a scan or photo, and quickly turn that image into reality. This also introduces opportunities for mistakes. A nice two foot part you drew could be cut as a mini two inch part because you have the units of measure incorrect. The better your drawing, the better your part will be. Follow these tips to create great drawings and to minimize the chances for mistakes.
1. Draw your part to scale
When drawing your part in Intelli-MAX LAYOUT or other CAD program, use a scale of 1:1. If you don’t, when the part is cut, it may be off by whatever odd scale you drew it in. It's easy to resize the part file if necessary keeping the correct relative dimensions if you start with a 1:1 scale. Make sure the units of measure in LAYOUT are properly set to the desired units to be used for the drawing.
2. Keep your drawings clean
Lines on top of lines, disconnected lines and an excessive number of endpoints in your drawing can prevent or slow down the process of turning the drawing into a tool path. If you're using Intelli-MAX LAYOUT, run the Cleaning Utility to search for and correct these types of issues.
3. Make sure your drawing matches your dimensions
If you draw a circle that is 5.3" (13.4 cm), but then put a dimension on it that says it is 5.0" (12.7 cm), it will still be cut at 5.3" (13.4 cm). Therefore, draw it the size you want it, so it gets cut that way.
4. Include only the part you want cut in the file
Every line in the file should belong to the part to be cut. Avoid including related parts, drawing revision information or other details that are not the actual part.
5. Smooth curves that are converted to many short lines
If you are using CorelDraw or Adobe Illustrator, you may need to go through additional file conversions to deal with curves. These programs will typically convert all curves to many short line segments when creating DXF files. This can result in your final part having curves that are faceted (although typically each facet is very tiny). There are a few ways to deal with this situation. The first is to just do nothing, and live with the faceted faces if this is low precision artwork. Another suggestion is to use the built-in converter in LAYOUT which will process an AI file so that curves are true curves. In order to do this, select File-> Import from other CAD… in LAYOUT and select the AI file that you want to import.