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By Daniel Dobrzynski, December 18, 2012
In the CAM field, it was always said that simple or inexpensive software solutions were applicable for performing only basic operations, and that users would reach the software’s limitations quickly. Well, I have come across at least one product (FreeMILL) that in a way contradicts the rule.
Here I review three CAM (computer-aided manufacturing) products from MecSoft:
MecSoft also provides interfaces for Rhino and Alibre, as well as export plug-ins for Inventor, SolidWorks, and SpaceClaim.
Figure 1: Example of 3-axis model in VisualMILL
Both VisualMILL and VisualMILL for SolidWorks have the same functions; the latter has the advantage of being fully integrated inside SolidWorks. I’ll begin my review of the standalone VisualMILL software, then I’ll describe the features particular to the software running inside SolidWorks, and I’ll end with a brief overview of FreeMILL.
VisualMILL and FreeMILL embed VisualCAD, an MCAD program that allows users to create geometry from scratch and to edit geometry to facilitate the CAM process. It reads the following file types: IGES, STEP, STL, Parasolid, VDA, VRML, RAW triangle, SolidWorks parts (sldprt), Rhino (3dm), and AutoCAD (dwf, dwg).
Before I introduce VisualMILL, allow me to provide an overview of the steps CAM programmers must always follow in preparing parts for machining. These steps optimize the organization and planning for programming:
The user may have to repeat all or some of these steps for subsequent operations. Let’s see how Visual Mill handles these tasks.
After installing and starting VisualMILL, I found that it had a user-friendly machining operations browser for managing the machine configuration, post, stock, and setup with a sequence of machine operations and the zero program position (steps #1 through #3). See figure 2. I was able to do configurations quickly, as they were quite logical in their procedures.
Figure 2: Example of a 5-axis model showing the machining browser and toolpath
For the machine tool definition step (step #4), I configured it manually though the interface (the settings depend of the number of axes). It’s possible to load a definition from the included library. See figure 3.
Figure 3: Machine tool definition in VisualMILL
When doing this manually, there are many options and so this will not be simple for some users. But keep in mind that we tend not to constantly configure machines, and so the time spent selecting the correct settings will save complications and delays in the future, even if the initial setup takes a long time.
In the next step, step #5, I chose the post processor, and here I was pleasantly surprised, because a wide range of post processors are available to support most of the popular machine controls, such as Heidenhain (several models), Haas, Deckel , Mori Seiki, Maho, Mitsubishi, Okuma, Siemens, and Fanuc (several models). Users, however, always ask for more, maybe because we like to have a diversity of models for certain drivers, such as Mazak and Siemens, among others.
Each post processor can be customized through file name conventions, extensions, default editor (Notepad, by default), and a very good and complete set of options to personalize the post, such as the block format, units, modes, motion, circle and helical/spiral definitions, feed rate and tool change format, spindle convention, multi axis output way, cycles, variables, and many others.
After I set the "where," I needed the "how": defining the sequence of steps for cutting the part, steps #6 through #8.
To define the stock, I had the options of inputting its corner coordinates, its dimensions, or else directly copying the model’s bounding box. I found the Align the Part and Stock function easy to apply. Then I needed to specify the material type for the stock geometry; the texture visibility can be controlled by users.
Next, I needed to define one or more setups. See figure 4. The setups depend on the orientation, to have the part aligned in the same way as it would be fixed on the machine tool for cutting. This can be set in different ways: either to Machine Coordinate System Align to Active Construction or Plane; or Set Orientation Parallel to XY or Z World; or About XYZ Axis Rotation Angle.
Figure 4: Defining the setup orientation in VisualMILL
I found this whole definition process quite simple, although this may vary according to the user’s experience. Then, I needed only to define the logical first step in the setup, the Work Zero position.
Now that I went through all of the definitions, I needed to start generating the sequence of machine operations. See figure 5. I should comment that the number of options to generate machine operations can be difficult for new users to do rapidly, but generally the process becomes dramatically faster as users gain experience with the product, and know the relevant points to be modified. In light of this, perhaps MecSoft could include some kind of template or library of predefined operations, which could be helpful to accelerate the process.
Figure 5: Toolpath editor in VisualMILL
Nevertheless, the environment is friendly and easy-to-use. Changing the sequence of operations, for instance, requires just simple operations that involve drag and drop. In my opinion, it would be a great visual help to users if each operation were to maintain an icon corresponding to its type -- similar to the objects browser or machining browser; instead, each operation is represented by the identical folder icon, along with the operation’s name. When there are many operations, I found that it took me longer to visually-locate specific types. A workaround is for users to always maintain a standard methodology for generating operation names.
Machine operations can be defined for 2-, 2.5-, 3-, 4-, and 5-axis operations. The option group structure is similar for all these types, with a main folder (specifying the name of the operation, as defined by the user) and the following subfolders:
Figure 6: Tool creation and selection
Figure 7: Dialog box for specifying feeds and speeds
Figure 8: Setting clearance options
I don’t have room to go into the details of all the parameters for the full range of operations, but I would like to describe some of them:
2.5 axes handles facing, pocketing, and profiling, and advanced operations like roughing, finishing, and re-machining. On cut parameters, I can define the cutting tolerance, direction, cut start side with the option of outside/inside for close curves, and the stepover control.
There is a complete set of parameters to control the cut levels (rough or finish), and a very good entry and exit motions settings (approach and retract). I want to highlight the folder that is dedicated to advanced cut parameters in which users can control the cut corner rounding, arc fitting, cut smooth transitions, and bridges creation.
3 axes includes not only roughing and finishing methods, but also advance machining strategies, such as specialized finishing methods for radius, spiral, and curve projection machining, along with additional powerful methods for machining complex shapes. With the cut parameters, it is possible to control deep Intol/Outtol and stock tolerances, the direction method (mixed, climb, or conventional), complete cut levels settings, and a good optimized machining with stepover and ramp control. As with 2.5 axes, there are also the entry and exit motion settings
5 axes contains roughing and finishing multi-axis operations. In this case, the cut parameters are very comprehensive, stressing cut pattern (parallel to X, Y, Z, or specified by the user), traversal cutting (one way or zig-zag), stepover, and the necessary controls of the tool axis (lead/lag and tilt angles). I found that the cut levels control has an understandable interface.
Regarding the management of entry/exit, there is a wide range of options that cover the most common ways for tool input and output, as well as transitions and connections.
Finally, I was happy to see the gouge check options, in which I could perform gouge checks for tool geometry (holder, shaft, and tip) against checked geometry, with the ability to detect collisions, and then decide on the strategy within the predefined options.
As you may have noticed, I could write many pages describing the wide
range of options, but as this is a review and not a tutorial, I will stop
here so that I can describe simulation briefly.
VisualMILL has different ways to run simulations: it allows me to control the speed, interrupts, toolpath step levels, and the stock's representation/visibility, with or without material removal.
This is, however, a neutral program code simulation, which means what we do not see the actual Gcode that the machine will receive. I couldn’t find a machine simulation, which would have been of great help to programmers, especially in cases of position changes between different operations and for processes with 4- and 5-axis functions.
Compared to a stand-alone CAM system, VisualMILL for SolidWorks saves me countless hours by automatically updating toolpaths when my model changes. Being integrated with SolidWorks means that I have just one interface to learn, saving me valuable time.
This fully-associative parametric CAD/CAM package makes VisualMILL for SolidWorks a powerful system. Indeed, MecSoft emphasizes that this add-on is very strong in three principal areas: easy to use, powerful, and affordable. I decided to analyze the add-on to determine whether the claims were valid.
Easy to Use. I verified the complete integration of the user interface. All of VisualMILL’s common functions are embedded in the main toolbar and in the command manager of SolidWorks. The machining operations browser and tools browser are integrated in the SolidWorks’ Properties Manager. This means that all major CAM functions are available in the familiar SolidWorks user interface. See figure 9.
All models are rendered inside SolidWorks’ windows, such as animations of toolpaths and cut materials. Because of the integration, all geometric CAD changes are reflected immediately on the CAM toolpath, and it can be regenerated with a simple button click.
Figure 9: 4-axis pocketing – cut levels options in VisualMILL for SolidWorks
Powerful Feature Set. As with VisualMILL, this add-in offers a range of functions from simple to complex, and the machining capabilities range from 2- to 5-axis. These are applied to native SolidWorks geometry, and so I agree with the power claim.
Affordable. The add-on is promoted as a lower-cost alternative to a stand-alone CAM program, with quick ROI (return on investment). This point is easy to check by comparing prices and functions between similar products working in the SolidWorks environment; however, features are relative to the needs of each customer, and so you will have to decide if it is economical.
I checked out FreeMILL, and found that it is a fully functional 3D milling package based on MecSoft's VisualMILL CAM software. With FreeMILL, you can import VisualMILL, IGES, STEP, DWG/DXF, Rhino, STL, VRML, and Raw Triangle files, but no proprietary CAD formats. You can run full simulations on part models, and output G-code programs to machine tools.
The product comes with over 200 pre-built post-processors. I surprised that this kind of product is free, with no limits to time, parts, posts, or lines of code. You can download the software from www.cncportal.com/downloadfree.htm, after registering with MecSoft.
VisualMILL and VisualMILL for SolidWorks are general-purpose, 2- through 5-axis CAM solutions specially targeted at SMEs (small and medium size enterprises) with a desirable combination of features, affordable price, ease of learning, and use. It does, however, lack a module for handling multitasking machines, like Mazak’s Integrex series, which complete all operations -- turning, milling, boring, drilling -- in a single setup.
Nevertheless, all the benefits are provided by the standalone software, yet you have the option to work directly in CAD environments that provide geometric interaction, such as SolidWorks, Rhino, and Alibre.
As a fan of all areas of CAM and an expert in the area, after trying both products I'm left with a positive feeling for their extensive technical capabilities, as well as their ease of use.
|Daniel Dobrzynski is a expert in the CAD/CAM industry with over 27 years’ experience as enterprise consultant. He has worked as a designer (mainly in automotive & aerospace areas of big companies), CAM programmer, post processor generator, advance machine builder for CAM simulation, PLM administrator, methodology and procedures creator. He has more than 20 years as a CAD/CAM/CAE certified trainer. . More...|