Preventing dense nodes or anchor points in your design file results in better edge quality for your parts. Read on for file setup and export tips to reduce node density!
What are nodes?
A vector file functions like a map that a laser, waterjet, or CNC router follows to cut your parts. Vector files are made up of vector paths. The beginning and end points of each vector path are known as anchor points or nodes. Curved paths will have anchor points along arcs (typically 1-2 points per arc) to define the geometry.
The cutting tool (laser, waterjet, or CNC router) will make a brief stop at each node in your design. This means the fewer nodes there are in your file, the smoother the cut edge will be.
For CNC routed parts, we need at least .400” between nodes in at least 2-3 areas to place fixture tabs.
What causes dense nodes?
Dense nodes in a design are often caused by bad file exports or use of 3rd party converters instead of exporting a file directly from your design software.
In a file that has exported badly, curved areas are typically broken into multiple line segments instead of exporting as smooth arcs, which results in many nodes in a small area due to the concentration of line segments.
Preventing dense nodes
Export a STEP file if you work in 3D
We recommend exporting a STEP or STP format file if you’ve modeled your part in a 3D software like Fusion or SolidWorks since STEP files rarely have node density issues. Just make sure your part meets our 3D file guidelines!
Vector file export tips
Follow our vector file export tips for your design software of choice to prevent excess nodes.
Fusion 360
If you need to export to DXF from Fusion 360, set up your design as a sheet metal part.
Then create a flat pattern, click DXF export, and tick the ‘convert splines to polylines’ setting before clicking OK.
Tip: if your part requires bending services, import our Fusion 360 sheet metal rules and set up your design with the sheet metal rule for your required material.
SolidWorks
When exporting a DXF from SolidWorks, shapes drawn using splines often come with excess nodes. If possible, draw curved shapes using arcs instead of splines.
Alternatively, you can try using the Simplify Spline tool before exporting if the tool is available in your version of SolidWorks.
The SolidWorks DXF/DWG system settings include Spline export options. Choosing ‘Export all splines as splines’ can result in fewer nodes as well!
Tip: if your part requires bending services, import our SolidWorks gauge tables and set up your design with the sheet metal rule for your required material.
Rhinoceros 3D
We have a step-by-step guide on reducing nodes in Rhino: How to Reduce Nodes in Rhino3D
AutoCAD
If exporting a DXF from AutoCAD, be sure to export splines as splines.
When the polyline setting is used, holes and arcs often show as polygons rather than smooth curves.
Go into your export options and check “Export splines as splines,” then right-click on the face of the part, and select “Export to DXF/DWG”.
Adobe Illustrator
First, select your part. Then, at the top toolbar, navigate to Object > Path > Simplify to simplify your paths and remove excess anchor points. We have a guide that shows how to use Illustrator’s Simplify tool: Simplify Complex Paths in Illustrator
Inkscape
You should be able to reduce the number of nodes in your designs within Inkscape using the Simplify command (Control L). We have guidance on how to use Inkscape’s Simplify tool in our blog.
Fixing dense nodes
If it’s not possible to export a design file without dense nodes, there are ways to fix design files manually after exporting the file.
DXF and DWG format files
If you have a DXF or DWG format file with dense nodes, you can download the free, open source program QCAD and use the program to manually redraw circles and arcs.
Other 2D file formats
EPS format files can be opened and simplified with the free, open source program Inkscape.
If you have access to Adobe Illustrator, there aren’t many 2D file formats it won’t open! Illustrator’s path simplification tool can help reduce node density in a pinch if you’re unable to export a clean file from your primary design software.
One last node
Although it’s good practice to prevent dense nodes if possible, don’t worry too much about this aspect of design. Our applications team reviews all orders before production and if we have any concerns about producibility, we’ll reach out! Ask our Support team anytime if you have questions about nodes.
