Note: This section will allow us to work in Fusion360 only, for an alternative option please skip this part and proceed to 5xMonkey Tutorial.
Download Fusion360 File
Back to Square 1: File Setup
Let's work with a geometric cube in order to understand how 3-axis and 3+2 machining strategy operates. We have separated it into 5 sides and will work through each roughing strategy individually. Our main task in the file setup is to secure the exact same position for the machining space and the digital space for all 5 sides of the cube as shown below.
An indexical 3+2 can be denoted by the three main axes (i.e. XYZ) plus the additional two axes (i.e. BC), that are accounted for the rotation of our C-head and the spindle. Be aware that a smaller cube inside represents our final result that will be roughed out of our given stock material, i.e. bigger cube is for stock.
Open Fusion 360, download the file, click Upload button and press Select File from the computer folder snd click Upload. Wait till the file uploads.
Top left corner, from Design, choose Manufacture, CAM Section of Fusion360.
Begin creating the setup for the cube and select the origin at the upper corner of the stock by selecting "Model origin". Work Coordinate System (WCS) is one of the most important settings to consider while setting up your stock as it defines a global orientation of the XYZ axis. Thus, WCS avoids incorrect positionings between work and machine coordinates.
The stock setup allows you to specify how much material should be removed from each side, in this instance we remove 5mm. In the window below, you can see the overall dimensions of our stock (i.e. before the roughing strategy) excluding the fixture tail which adds another 25mm.
Once our setup is completed, we can start working on an individual strategy for each side. Here we implement an Adaptive Clearing for the roughing, which is a unique type of cutting speed machining strategy. The idea behind it, it keeps constant force on the tool by keeping the engagement same over the entire cut.
Adaptive 1: Top Side
Start working on your first roughing strategy (i.e. top side), where you see five main tabs to work with. The very first top side on its own shows a good representation of how 3-axis machining works as it doesn't require an additional two axes for repositioning from one operation to another.
Note: The majority of settings were set by default as we attempted to keep this tutorial simple and leave all the complex aspects for later tutorials.
1. Tool Tab is where you pick the tool from the Tool Library. Feed and Speed rate comes along with the tool defined earlier, although you can customise it manually.
2. Geometry Tab captures what will be removed out of the preselected stock.
3. Heights Tab defines movements of the tool such as clearance and retraction, specifying heights at which the operation functions.
4. Passes Tab defines how aggressive the depth of our cuts are.
In the Linking Tab, select Minimum retraction in order to save time during the milling stage.
Press OK and begin simulating the process. This will allow us to remove 5mm of the stock material and form the cube.
How to rough out the rest of the sides?
While the top side of our cube is pretty straightforward to follow, we should also consider the transition from one side to another, which essentially makes it 3+2 operation.
The quickest way is to duplicate our previous operation (i.e. top side) by right-clicking on the icon.
Then, we should adjust the Geometry Tab, in particular, the tool orientation appropriate to the next side that we want to rough out. To select side of the cube in the Tool Orientation section, choose "Select Z axis/plane & X-axis" and select your orientation (i.e. Face) for the Z-axis. Pay close attention to the orientation of XYZ, Z-axis shows where the tool is coming from. For the Origin below, pick our preselected WCS origin from the setup.
Adaptive 2: Left Side
Proceed to work with the second side of the cube, i.e. left side.
Note: Once our second side (i.e. left) of the cube is done, we can apply these settings to the rest of the strategies. To select side 3 (just like any other side) click Face and select an appropriate side of the cube.
In other terms, you need to adjust the tool orientation appropriate to the side of the cube and apply these steps for the rest of the sides.
Once all five roughing strategies are completed, select them individually and simulate to check on the toolpath and any potential collisions between the tool and the fixture/stock.
Once you simulate the toolpath, click on Stock to see the stock material, in this instance, the toolpath was switched off and the stock was set to transparent.
Post-processing G-code and Mach3: perform individual strategies only.
For Fusion360 post-processor installation, please watch the video below:
You should consider avoiding the multiple operations on 5XM, always retract your machine after each operation. The reason why combining strategies all together into a G-code might not be a good idea is simply because of the machine being unable to recognise the exact position of the stock in the machining area, rather it recognises the particular coordinates to which this stock is attached.
For more information on how to run the machine and useful tips prior to the usage, please go to How to Run the Machine.