CAD/CAM part programming involves arranging and documenting the sequence of tasks to be carried by 5axismaker. The CNC procedure can be summarised in four steps:
1. CAD (Computer-Aided Design): sketch and design the geometric model up to three dimensions.
2. CAM (Computer-Aided Manufacturing): select milling tools and assign toolpaths to each side of the model.
3. Post-Process: generate G-code in the word address format.
4. CNC Controller: install CNC controller software (i.e. Mach3 or Mach4) and load G-code.
We will introduce an alternative software allowing to create a manufacturable design of the model.
5xMonkey: is an in-house made script to generate 5-axis simultaneous code to run our 5-axis CNC machine as opposed to generating G-code on a standard CAM software.
Fusion360: is a cloud-based CAD/CAM/CAE tool that mainly provides an indexical (i.e. positional) machining (3+2 axis).
Please ensure a full understanding of all the steps required for CNC milling:
File Setup - Fusion 360
In this case study, you will learn how to:
1. set up digital stock in Fusion360
2. perform roughing and finishing strategies (i.e. proceed to the further sections)
3. measure tool at full accuracy and define CAM tools in Fusion360
4. edit post-processor in Fusion360
Roughing pass is used to take the bulk material from the stock and shape it more towards finished form while leaving a specified amount of stock layer. Select the toolpath that will be used to cut the model out of stock.
Finishing pass is the polishing stage, that is no different compared to the roughing stage.
Fusion360 can be used to create positional (3+2) and simultaneous 5-axis toolpath for CNC milling. 5-axis milling is widely used in machining complex geometry, hence we will perform. To begin working in CAD/CAM workspace download Fusion File and import the model. Both Roughing pass and Finishing pass are done from two sides and more.
|Tip: S button allows to summon the “Shortcuts” window where you can search for any existing command/function in the software.|
For example, if you’re willing to adjust the units: Shortcuts button -> type units -> change the unit type.
Preparing the Virtual Stock
Before proceeding to the CAM workspace, it is highly advised to create the stock from the solid body in the Design section (i.e. CAD). This allows readjusting the model within the stock. The stock can be any shape as its possible to create the same dimensions for the digital stock in Fusion360.
Create -> Box -> set the required dimensions for the stock. For the case study, the dimensions of our stock are 180x430x110 mm.
Note: It is possible to select the negative value to extrude the stock box below the grid line.
Begin working in CAM workspace -> Setup
Please ensure the adjustment between the CNC controller (i.e. Mach3 or Mach4) and the 5axismaker. To do so, we must pay close attention to the creation of the digital stock and verify its perfect fit for the model. Each setup specifies:
- the position of the model
- axis directions which should be set up the same as in your machine’s physical space
- stock outline
- model position in relation to stock.
Note: Ensure on the vital points while carrying out the Roughing/Finishing stages:
1. Always refer to the same origin.
This technique is widely used to avoid incorrect positioning between work and machine coordinates.
Work Coordinates System (WCS) – a global orientation of XYZ axis, part of the setup for every cutting strategy. (i.e. the top left corner of the stock is at X0, Y0, Z0)
Tool Orientation – local orientation of the tool in relation to XYZ. (i.e. part of Geometry Tab for every cutting strategy).
2. Refer to the Setup for every cutting strategy.
This option will automatically apply setup details to every cutting strategy, thus avoiding any possible errors.
Work coordinate system should be set as per model orientation (Z up). X, Y, Z directions and zero value should match in both machine’ space and digital space.
If working with a block of material either use "Fixed size box" and specify the dimensions or draw your stock and select it as a solid model. "From solid” option specifies on your pre-drawn stock.
Select a Tool
Create digital tools that will be used for both Roughing and Finishing passes.
| Tip: enable the Cloud Library, so your tools and post-processors are sharable between computers. Right-click on the user name in the upper right corner -> Preferences
-> General -> Manufacture ->ensure the tick on Enable Cloud Libraries
In the upper bar Manage -> Tool Library -> click on Cloud or create an individual folder -> New Mill Tool
The window below captures the tools that we have created already.
Select the type of cutter and enter the dimensions of your tool. We advise using the most accurate methods available for measuring tools. (e.g. micrometre, dial, digital calliper) For more details, please proceed to the Machine Setup. NEW LINK
Feeds and Speeds are referred to the combination of settings, including speed, depth of cut, the width of cut, and it would always vary on property material. These settings need to be adjusted appropriately with the stock material and the tool length.
Feed Rate: Allows to control the velocity of each machine axis, including the rotational speed of the tool spindle.
RPM (revolutions per minute): It is the frequency of spindle rotation, in other words, how fast the tool is spinning per minute.
Surface Speed: Also known as "cutting speed", it is the speed difference between the tip of your flutes and the centre of the tool.
FPT (feed per tooth): Stands for the relative thickness of each chip, which essentially affects the overall life of the tool.
DOC (depth of tooth): Estimates the height of the chip being cut during machining.
WOC (width of cut): Estimates a relative depth of cut, which also determines how deep the tool is engaged in the cut.
For more information on Feeds and Speeds recipes, please proceed to our official website.
Before generating G-code, we need to make sure Fusion360 recognises 5axismaker for CNC milling. Each CAM package requires a post-processor made specifically for 5axismaker to take full advantage of 5-axis capability. Download the latest 5axismaker post for Fusion360 by visiting Autodesk Post Library.
For all the steps on how to install a Personal (i.e. local) Post Processor in Fusion 360 CAM please follow this link.
After going through all the steps your Post Process window should look like this:
Name the file, click OK, and save .tap file anywhere on your computer hard drive. Run in Mach3 or Mach4.