Guide
How to prepare a DXF for laser cutting
A laser cuts exactly the lines in your file, so a clean DXF is the difference between parts right the first time and a drawing that comes back with questions. Here is what we look for, and what lets your part price instantly when you order online.
The short checklist
- One part per file, at full size. Draw the part 1:1, in inches or millimeters, never scaled to fit a sheet.
- Every outline closed. The outside edge and every hole or cutout must each be one closed loop, with no gaps, no overlapping lines, and no lines drawn twice.
- Only the lines to cut. Take out title blocks, borders, notes, center marks, and any dimensions that have been exploded into plain lines.
- Know your units. Set the file's units to match the drawing, and choose the same units when you upload. We draw the part back to you dimensioned, so the size is easy to check.
- Save as an ASCII DXF. Not a binary DXF, and up to 2 MB. Any DXF version from the last twenty years is fine.
- Holes no smaller than the steel is thick. In 1/4" steel, make holes at least 1/4" across. Smaller holes can be cut, but we look at them first.
The details that cause trouble
Open outlines
A gap of a few thousandths between two lines is invisible on screen, but the laser can't follow an outline that doesn't close. In most CAD programs, joining the edges into one polyline, or running a check for open contours before you export, finds them.
Splines and partial ellipses
Curves drawn as splines, or as part of an ellipse, are approximated when they are read, and the part goes to our office to check rather than pricing online. Converting them to arcs and lines (a polyline) before you export avoids that and gives the laser a smoother path.
Several parts in one file
Upload each part as its own file, and set the quantity on the order page. A sheet of nested parts can't be priced online, and we nest your parts on the sheet ourselves.
Text and engraving
Text that should be cut through the part has to be converted to outlines first, and letters with enclosed centers, like O, A, and R, need bridges or a stencil font, or their centers fall out. Notes and dimensions left as text or dimension entities are ignored, so they do no harm.
Bends
For a part that will be bent, send the flat pattern and tell us the bends. Online orders are flat parts; bending is quoted by our office, so send the drawing for a quote.
Size limits
Online, parts can be from 1/2" across up to 6' long and 30 lb, in carbon steel from 11 gauge to 3/8". Larger, heavier, or thicker parts, and stainless or aluminum, are quoted by our office.
Exporting from your CAD program
The menu names change from version to version, but the steps are much the same everywhere.
- Fusion 360: make a sketch of the part's face, then right-click the sketch and save it as a DXF.
- SolidWorks: on a sheet metal part, export the flat pattern; on a plain part, save the face as a DXF at 1:1, with only the part's geometry.
- AutoCAD and DraftSight: delete everything but the part, check that each outline is a closed polyline, and save as an ASCII DXF.
- Inkscape and Illustrator: convert text and strokes to paths, check the document's units and that it is at 100% scale, and save as a DXF.
Not sure your file is right? Upload it on the order page: it's drawn back to you with its size and holes dimensioned, and anything the laser can't cut as drawn is listed, before you pay.
DXF questions
What is the best file format for laser cutting?
A DXF of the flat part, drawn 1:1. It is what laser cutting software reads directly. A DWG, STEP, or PDF works too when you send it for a quote; we convert it in the office.
Should my DXF be in inches or millimeters?
Either. What matters is knowing which, and choosing the same when you upload. A part drawn in millimeters and read as inches comes out 25.4 times too big, which is why we draw it back to you with its size before you pay.
Do I need to allow for the laser's kerf?
No. Draw the part at its finished size; the laser's path is offset for the cut's width when we program it.
How small a hole can be laser cut?
As a rule of thumb, in steel, a hole about as wide as the steel is thick. Smaller holes are possible in some cases, and we check them before cutting.
Have a drawing ready? We'll quote it, or order online with an instant price.