CNC machines are controlled by sophisticated CAM software that transforms digital designs into solid parts. But not all programs are alike or produce the best results for every design.
To optimize your parts Star Rapid has invested in an additional layer of security called Vericut, the world’s leading virtual simulation software for CNC machining. Learn more about what Vericut is and why we use it to improve the quality of your finished parts.
From CAD to CAM
Every job starts when you upload a 3D CAD file of your design. A machinist then uses a CAM program such as Autodesk’s PowerMill to convert the graphic data of your 3D CAD file into a preliminary cutting program.
Each program is unique. Not only because of the geometry of the part, but also because of the choices that the machinist will make for the kinds of tools they want to use and the path that they should follow.
From CAM to Simulation
Because every cutting program is specialized, each must be verified using a virtual simulator. This identifies and solves some potential errors before there is actual raw material loaded on the work table. We also use the simulation to modify the tool path to improve the surface finish for example, or decrease the cycle time.
Programs like PowerMill have built-in simulator functions but they don’t accurately model every possible kind of machine. This can lead to potentially serious problems which we discuss below.
From Simulation to G-Code
Once the simulation is confirmed we convert it to G-code using post-processing software.
G-code is the file of line-by-line instructions that tells the CNC machine exactly how and where to move. There may be hundreds or thousands of lines of code in a program, so it’s essential that every instruction is exactly right. However, machine manufacturers use proprietary encoders and other internal hardware and software and they don’t necessarily all interpret G-code in the same way.
From G-Code to Machine
In ideal circumstances the G-code program can be sent directly to the CNC machine.
The cutting program will be cycled and a finished part emerges from a piece of raw stock. But in reality it’s not always that easy.
Potential Problems
One type of problem can happen if there’s some slight translation error between the original CAD file data and the G-code. This might make a part out of specification or with a poor surface finish. Of course, if the part is scrapped that means wasted time and money.
Another much more serious problem can occur if the program doesn’t account for every other object inside the machine’s working volume. Potential obstructions might include tool holders, vices, rotary tables, coolant lines, steady rests, etc. Accidental collision with any of these or with the worktable can seriously damage the workpiece or the machine and even endanger the operator. A collision of this kind must therefore absolutely be avoided.
To protect against this, conventional workshops tend to cycle a new program very slowly and then make a series of micro-adjustments based on a lot of back-and-forth measurements. This wastes a lot of time, and that means more expense for you.
What Does Vericut Do?
Vericut does much more than analyze G-code for potential errors, although it does that very well. It creates a virtual map of everything inside the machine that could cause a collision, and it’s able to rotate this map on multiple axes to accurately emulate the actual working environment.
This extra layer of verification protects worker safety, avoids costly machine downtime and improves process efficiency.
Vericut is optimized to work seamlessly with all major machine controllers and encoders. It enhances tool paths and greatly reduces job set-up times. It can even be used as a virtual training program to upgrade operator’s skills. Vericut has saved us hundreds of hours of production time and helps to avoid preventable maintenance shut-downs while improving tolerances.
The use of Vericut is just one of the many ways that Star Rapid is constantly investing to ensure we offer the fastest and most reliable rapid prototyping and low-volume manufacturing service in the industry. If you enjoyed this article you can learn more about CNC machining here or follow this link for more information about G-code.
