A DXF that opens correctly is not the same as a DXF that cuts correctly. The gap between the two is four checks, and they take about ten minutes on the first part of every job.
1. Units: decide before you import, not after
DXF carries no reliable unit. A 24 in panel and a 610 mm panel are the same set of numbers scaled by 25.4, and every CAM package will happily cut the wrong one. Decide the unit in the import dialog, then verify against a dimension you can measure with a tape — never against the screen.
All Northpine DXFs are drawn in inches at 1:1, with the millimetre equivalent printed on the corresponding PDF sheet.
2. Verify one known dimension
Pick the longest part, use the measure tool, and compare it to the cut list. If the side panel should be 36 in and the tool says 914.4, you imported millimetres into an inch job. Stop and re-import; do not scale after the fact, because toolpaths already generated will scale with it.
3. Tooling: the numbers that actually matter
For 3/4 in plywood with a 1/4 in downcut or compression bit, a workable starting point in a hobby router is 18,000 rpm, 100 in/min feed, 30 in/min plunge, 1/8 in per pass. Those are starting numbers, not gospel — your machine, your collet and your bit decide. What matters is that you write them down once and change one variable at a time.
4. Holding: tabs, screws, or vacuum
Small parts move. A 4 in shelf stop with no tab will become a projectile. Use 0.1 in tabs on anything under 6 in, or screw through the waste area. If you screw, place screws where the toolpath will not find them — mark them on the nesting map before you start, not during.
5. Origin and zero, every time
Decide whether zero is the bottom-left corner of the sheet or the corner of the part, and set it the same way on every job. Most ruined sheets are not cutting errors; they are a job cut in the wrong place on a good sheet. Write the origin on the sheet in pencil.
The four failures that eat a sheet
- Open vectors. A profile that looks closed on screen but is not will leave a part hanging by a sliver. Use the join/close tool and check the entity count.
- Duplicate lines. Two overlapping lines mean two passes in the same kerf, and a burnt edge or a broken bit.
- Wrong scale. Covered above, and it is the most common by a wide margin.
- Kerf ignored. If you nest by hand inside the CAM package instead of using the supplied map, add 1/8 in between every part.
A ten-minute ritual before the first cut
- Import with the unit set explicitly.
- Measure the longest part against the cut list.
- Close and de-duplicate vectors.
- Set tool, feed, plunge and depth per pass from your saved preset.
- Add tabs to anything under 6 in.
- Cut the smallest part out of scrap first.
When that becomes habit, a DXF stops being a file that might work and becomes a cut list you can trust. Every Northpine plan ships the same DXF/SVG pair with a matching PDF sheet, so the dimension you verify on screen is the one printed on paper.