Fusion 360 machine simulation simulates movements from the post-processor. To achieve this simulation, some minor post-processor updates are needed and in certain cases, a slight workflow change. This article will outline the reason for the change and also explain the needed modifications.
First off, start by checking if there is already a simulation-ready post-processor available for your machine. To do this, simply open the post library inside of Fusion 360 and select the 'Fusion 360 library' with the 'machine simulation' filter enabled:
If there is not a post-processor that supports your machine, follow the instructions below to update your existing post-processor to support machine simulation. For reference, a sample post-processor that contains all of the needed modifications can be found >>here<<
Important: Prior to making any post modification, it is important to make a backup of your existing configuration. Once the desired changes have been made, manually check the output code test very carefully on your machine tool. A guide on how to test and prove out your post-processor can be found >>here<<
Removing a hardcoded machine configuration
When using machine simulation, your post-processor must not have any kinematics applied directly inside of the postscript. Instead of defining the kinematics inside of your post, you should use machine configurations from within Fusion 360.
A commonplace for machine configurations to be set in the post-processor is within the onOpen function. at the top of this function definition, you will likely find a block of code similar to this:
if (true) {
var aAxis = createAxis({coordinate:0, table:true, axis:[1, 0, 0], range:[-120.0001, 120.0001], preference:1});
var cAxis = createAxis({coordinate:2, table:true, axis:[0, 0, 1], range:[0, 360], cyclic:true});
machineConfiguration = new MachineConfiguration(aAxis, cAxis);
setMachineConfiguration(machineConfiguration);
optimizeMachineAngles2(0);
}
To disable the kinematics from this area, change the first line from if (true) to if (false). The result should look similar to this:
if (false) {
var aAxis = createAxis({coordinate:0, table:true, axis:[1, 0, 0], range:[-120.0001, 120.0001], preference:1});
var cAxis = createAxis({coordinate:2, table:true, axis:[0, 0, 1], range:[0, 360], cyclic:true});
machineConfiguration = new MachineConfiguration(aAxis, cAxis);
setMachineConfiguration(machineConfiguration);
optimizeMachineAngles2(0);
}
Updating post processors for machine configuration support
It is recommended that you update your post-processor with the latest generic code for Machine Configuration support. The new code fully supports hardcoded machine configurations as well as Machine Configurations defined in Fusion.
To implement this code in your post processor please refer to the machinesimulation.cps post-processor and search for the following two lines ...
// Start of machine configuration logic
........
// End of machine configuration logic
... and copy this entire section into your post-processor.
You will also need to copy the code from within the onOpen function of the machinesimulation.cps post-processor to the start of the onOpen function of your post-processor.
Multi-axis operations
To use machine simulation on a multi-axis machine, the post-processor must send back the appropriate machine angles which are selected for an operation. To do this, simply add the following code to the area of the post-processor which is responsible for setting your machine ABC values (typically at the end of a function called setWorkPlane()):
setCurrentABC(abc);
Important: Your post processor must use machine angles and not vectors / Euler angles for multi-axis output. When using vectors or Euler angles, the machine will choose how to reach a programmed solution which means that simulation would need to guess what solution is selected. To ensure the simulation is accurate, we only currently allow machine angles to be simulated.
Capability
Finally, Fusion must be aware that you have gone through and updated your post-processor to support machine simulation. To tell Fusion this, simply add CAPABILITY_MACHINE_SIMULATION to your post's capability definition (at the top of the post). Once done, it should look something like this:
capabilities = CAPABILITY_MILLING | CAPABILITY_MACHINE_SIMULATION;
