How to generate NC code for machining a simple part in Siemens NX- PROJECT 1

Siemens NX is a popular CAD/CAM/CAE software used by professionals all over the globe. It provides an intuitive interface for creating different geometries and machining operations for them. The basic modelling interface is similar to many other CAD software. The steps to be followed for the operation as shown in the video are:

• Create geometry in modelling environment

1. Select new file.
2. Give any suitable name and specify folder to save it in (it is recommended to use a separate folder outside the parent NX folder to avoid issues afterwards).
3. Select model (first option) and units in mm(or any other of your choice) and hit OK.
4. Choose 'sketch' and specify the plane to sketch upon. Select 'inferred' in plane options. Hit ok and create the sketch.
5. Select the 'extrude' option in the ribbon and select the curve drawn in step 4. Then extrude it by the desired amount [1].
6. Perform any other operation to complete the model. Once completed, proceed to the next section.

• Create and define operations

1. To go to NX manufacturing, press ctrl+alt+m (to switch back to modelling use ctrl+m).
2. Select the appropriate CAM setup and session (mostly you will use cam_general and mill_contour for this project).
3. Right click and select geometry view.
4. Double click on MCS MILL and select the MCS for the job [2].
5. Double click on workpiece and specify the part and blank (bounding block in this case) [3].
6. Click on create tool (with the workpiece highlighted) and provide the details of the tool you are going to use (in most cases, diameter and flute fields are sufficient). Alternatively, right click on workpiece and select insert→tool
7. Create operation→select suitable operation type(cavity mill in this case)→OK
8. Specify cut area→select the walls and the floor (in this case)
9. Select the tool you just created.
10. In the path settings, select the appropriate tool path (follow part in this case).
11. In stepover select constant and specify maximum distance of 2mm (Ae).
12. In common depth of cut give 5mm (Ap)
13. Feed and speed→specify speed and press enter and then click the calculate icon next to it. Similarly specify the feed.
14. Click on the 'generate' icon (first from the left) on the bottom to generate the tool path→OK.

• Simulate the machining and generate NC code

1. Click 'simulate machining' and hit the play button. Adjust the speed according to your need.
2. Right click on workpiece in geometry view→post process.
3. Select the appropriate postprocessor and give the name of the file and its format(.mpf in this case).
4. Hit OK and your NC code is generated.

The generated NC code can be directly fed into the CNC machine through the USB port and the part can be machined readily as shown in the video below:

Have a look at the thermal imaging of the above milling operation in the video below:

P.S:

[1] For the extrude command, there are many options. You may unite or subtract two geometries from one another. For the given example just choose subtract as shown in the video. There will be a dedicated video showing every detail in the near future.

[2] MCS stands for machine co-ordinate system. You must specify the MCS as all the calculations for generating the NC code are done based on it. There are a number of ways to choose the MCS of your choice. The CYCS menu gives you tons of ways to do so. Just fiddle a little with the options or wait for my next video tutorial.

[3] The part (workpiece) must be specified along with the blank. To select the blank, use the drop-down 'type' menu and select bounding block (for the present example). More on this later.