18.06.2019

10 Reasons to Use CAD/CAM System Simulations for CNC Programs

Today, the author looks inside the reasons of the costly errors appearing during cutting of metal, and the possible ways of eliminating them beforehand. The most suitable tool is a computerized machining simulation which today is an essential part of many CAD/CAM software packages and applications.

Every shop has experienced the negative impact of a machine collision, tool break, or untimely part gouge. These can have serious financial impacts on a business by way of repair & tool replacement costs and machine downtown.

With complex machining, any one of these errors can easily happen. Even with simple machine operations, these can still occur if proper care isn’t taken. Errors could be caused by any number of reasons including improper tool selection, fixture set-up, or the more likely cause is a simple programming error.

Shops that use CAD/CAM software to develop their CNC programs can fall back on the software’s simulators to help eliminate these types of productivity killers. As CAD/CAM software has advanced, so has the user’s ability to realistically visualize the machining process.

It’s the simulator’s job to identify potential programming errors in an off-line setting, before the g-code is ever created and transferred over to the CNC machine. In the last 10 years, simulators have become so successful at identifying costly machining mistakes that shops, small and large, that use them consider simulators vital to maintaining their profitability.

CAD-CAM System Simulations: Break pixels, not $100,000 machines.

Integrated directly into the CAD-CAM software, simulators are no longer reserved for the expensive systems. Affordability combined with advancements in computer hardware and graphics capabilities have made simulators accessible to job shops of all sizes.

What features should have you implementing simulators into your machining process today?

• 1. View and proof cut paths from any angle
• 2. Set machine travel limits and detect over travels
• 3. Check for part errors – including machine, tool, and tool holder collisions
• 4. Utilize you machine’s kinematics to visually see your machine tool in action
• 5. See exactly how the part will look cut on your machine at any point during the machining process in a virtual environment
• 6. Set up an unlimited amount of virtual machines that match the machines in your shop
• 7. Assign transparency levels of the simulated machines for enhanced part viewing ability
• 8. Accurately calculate cycle times
• 9. Use dynamic viewing functionality for better inspections
• 10. Identify machine-part deviations to know where tools were unable to machine within the associated operations.

The big picture benefits include less time wasted on machine errors, fewer parts scrapped, and general peace of mind knowing you have more control over your machining process.

Identifying the Machined Part Deviation

In setting up the simulation, the user can define deviation tolerances with color assignments. When the operator runs the simulation, any areas where the tool left excess material will be clearly identified. This works for both milling toolpaths and drilling operations.

In addition to color identifiers on the virtual part, the CAD-CAM software will list any deviations in a customizable deviation analysis tab. With two ways to identify deviations, the user can easily determine ideal surface finishes and any problems associated with the current tool selection and size.

Advanced CNC Machine Simulation

The simulation feature is designed to provide realistic virtual machining, which includes importing the kinematic features of the actual machine in the user’s shop. Machine creation begins with defining each element of the machine to be used, such as the linear and rotary axis attributes. Next, parameter values are established, including the moving direction and limits. This is essential data for the CAD-CAM program to generate accurate g-code for the NC programs. For each element, geometry files (.stl) are added to define what appears in the simulation window.

Once the machine data is entered, the user can save the machine for future use and machine simulations are now possible.

One thing’s for certain, CNC machine simulation is NOT a fluff feature. Its empowering designers and operators with the tools necessary to increase workflow efficiency, reduce machining errors, and most importantly, increase profitability.

Dreambird's comments

EDGECAM, a software solution for milling, turning, mill-turn and multi-axis equipment, offers strong simulation capabilities. The Simulator program offers full simulation of the machine tool and machining process for lathes and milling machines, as well as collision detection for common machine collisions, helping you to avoid expensive collisions, optimise the cutting process and reduce cycle time.

Simplified block graphics are created by default and their dimensions can be parametrically adjusted to suit the machine tool configuration.

Optionally, you can substitute the parametric graphics with your own fully detailed graphics by modelling the machine tool in a solid modeler. Elements of the machine tool such as heads and turrets are represented as graphics. The 'Machine tree' provides an easy-to-use method of controlling the display and kinematics of each machine tool component. The graphics are positioned in an axis configuration built into the Machine Tree (such as upper ATC on the B Axis, B Axis on the Y Axis and so on, or Table on the C Axis, C Axis on the A Axis and so on).

There are also graphics for fixtures, such as tool mounting blocks, and chucks that you can store in a library for use in the machine tool simulation.

The machine simulation setup is contained in the code generator, as created in Code Wizard. For correct simulation you need to specify details such as the axis configuration and the home positions.