CNC jobs can be difficult to set up correctly and some errors may not be identified by the technician. To ensure the best outcome for your job, please refer to this Tips & Errors.

Ensure Lines/Curves are Planar

Check that your geometry is at the top plane of the stock and that no points are below by examining the left, right and front view ports. Refer above to correct example of selected geometry in yellow. Use command SETPT > Z Axis

Join/Close Lines and Delete Duplicates

Duplicate lines may cause confusion to the Fab Lab and must be deleted. The command SELDUP will remove most duplicates but you must also conduct a manual check. Overlapping lines may be simplified by the command MAKE2D. Join together lines using command JOIN. Lines that are used to specify different operations must not be joined.

Close geometry that is to be Profiled, Pocketed or a Containment Region.

Allow at Least 30mm Between Objects

Unlike the lasers, nesting of objects is best done by allowing for a profile of each individual object of at least 30mm.

Please do not attempt to share edges for small objects.

The Fab Lab will advise you during your consultation as to the best nesting practice for your geometry.

Don't Group Objects

The best way to control your geometry is by the use of the layers provided or the creation of additional layers using the proforma. The grouping of objects is not suggested as the Fab Lab may be required to alter the nesting of your geometry.


Bits are cylindrical in shape and work by high speed rotation. In plan, a bit is best represented by a circle.

Unlike a laser, which has a beam width of less than 0.5 mm, a CNC bit is usually 6.35mm or larger. If you conceptualise a circle moving in plan you will have a good idea as to the routers limitations.

This means that sharp internal corners are impossible to achieve without post processing or other machining methods.

Last updated