This page is under construction and not complete. Always ask the labmanager for help on the milling machine.

This wiki page is about the CNC Step High-Z S1000 milling machine. This is a medium sized milling machine, with millable dimensions of 600 x 1000 x 100 mm. The object on the table can be larger, limited to a width of 625mm and an “infinite” length. It is technically possible to mill a 600mm x 2000mm object, but you will have to shift your workpiece halfway.

The milling machine has a 1000 watt spindle, with an adjustable rotation speed of 5000-25000 RPM.

DeskProto website

DeskProto is a software CAM package that is specifically designed for milling 3D objects. This program allows you to import several file formats, of which the .STL format is prefered. STL files can be exported from most commercial modelling packages.

When using Alibre Design for instance, one can create a to-scale model of the object that needs to be engraved. By importing the .stl file in DeskProto, a cutting plan can be made. Note that 3D milling can take several hours for big projects. Therefore, it is important to choose your tools wisely. Use a big diameter tool to do the rough surfacing, and then switch to a smaller milltool for the details.

Upon starting DeskProto, a tutorial wizard will start. If you want to do 3D engraving from a STL model, this is a pretty straightforward wizard. It allows you to rotate your work piece in the way that is most efficient for milling. Note that the mill can only drill straight down, so if you need your model to be milled from several sides, you will have to configure this in the wizard. In the photostream are some examples of what you can expect in this wizard.

There is a great tutorial on how to use DeskProto on the website of Delft Spline Systems, Tutorial. After you have completed the wizard, there are some manual settings that can be adjusted while clicking on the 'milling tree' on the left side of the screen. It is really important to think about how the mill should cut, cutting against the spindle rotation in wood is better than along with the spindle rotation for example. Try an experimental run on a small piece of test wood/foam before you start the final cut.

3D Milling can take a very, very long time if there is much 'waste' material to be milled. Make sure your step size and toolpath distance is appropriate. A good tactic is to use a 6-10mm mill with a 5 mm stepsize and 5 mm toolpath distance for the roughing, and then start a smoothing run with a 2-3mm mill and small stepsizes. Always do a quick calculation on the estimated production time, it is not always 100% accurate, but at least it gives you an idea.

Vcarve Pro is a 2D/2.5D software CAM package. It is especially useful for engraving and cutting in large flat surfaces. Vcarve is easy to use, and has several options to import EPS and AI files. (vectors). These vectors can be converted into toolpaths.

Stub needs to be expanded with a small tutorial

ATTENTION!: It is NOT possible to import vcarve pro files generated on the TRIAL version at home in the lab. It is advisable to take a notebook with you if you created files using the trial version, because you will have to export the NC files manually.

To use the CNC step mill, you will have to power the computer next to it plus both controllers in the cabinet. Beware: The first time you power the controller, the spindle will start rotating. Once WinNC is started, you can disable the spindle. It might be wise to just unplug the spindle power cable while you are setting up, to prevent you and your fellow labworkers from hurting yourself.

Win PC-NC is the software package you will use to mill the object. It is a software driver for the machine. It uses a “line based” program/algorithm to drive the machine. These files are exported from cnc/cam programs like vcarve pro or DeskProto.

The next two screens show the most important settings before you get started:

The Z-coordinate (up/down) needs to be inverted for Vcarve pro files. Not doing so might damage the machine, so be careful!

One of the hardest tasks on milling machines is to keep track of the different coordinate systems one uses. A handy way to work is to use the vcarve pro object sizes as a reference. If you want to do this, you will have to tell winpc nc to do so too. By default, win nc pc uses the first vector to cut as a zero point.

At the time of writing of this article, there is One kress spindle in the lab available. This means that you occasionally will have to change your tools. If you need to mill large area's, you will probably use a 6mm-8mm tool for the roughing, and then move on to a 3 mm tool to make the final adjustments and get the shape in.

Changing tools isn't hard:

- Unplug the kress (safety) - there is a little button near the spindle head, you can push this to “lock” the head - while locked, unscrew the head - change the tool

If the tool has a different diameter than the one that was in there, you will have to change the clamp as well.

Make sure you don't push the mill in too far, this will limit the depth you can mill.