In the world of computer-controlled milling equipment, there’s always been something of an understanding when it comes to work envelope and precision: as the ability of a machine to achieve ever smaller numbers when it comes to positional accuracy and repeatability goes up, the size of the work envelope (and therefore the largest part you can physically fit in the machine) must go down. Now, like any rule of thumb, there are exceptions to this out there – but these exceptions generally carry with them one significant caveat: they’re expensive as all get-out. Enter DATRON MLCube LS Large Format Milling Machine with linear scales.
There are many legitimate reasons that this convention has become the norm. In ball-screw-driven machine tools, using a ball screw with a very tight pitch to achieve stellar accuracy and repeatability usually results in a decrease in the maximum rapid rate – which is a real bummer if you need the machine to move large distances. Technologies such as linear motors are capable of moving very fast over long distances, but sacrifices often need to be made when it comes to resolution and accuracy of the encoders that feedback the motors motion to the machine’s control system. Even linear scale technologies, while being readily able to increase a numerically controlled machining system’s ability when it comes to accuracy and repeatability, must by default be an additional piece of hardware which accompanies the linear motor or ball screw/linear guide system. Any additional hardware, as any engineer will tell you, is subject to damage, misalignment, or in the case of milling equipment -contamination from the chips, dust and coolant that are part of the milling process. It would seem that the combination of large, capable, precise, and economical has been an elusive one in machine tool industry.
Fortunately, this very problem that the DATRON MLCube LS has been created to solve.
Linear Scales for Precision in Large Format Milling
The ML Cube LS represents the latest in a long lineage of ever improving portal/gantry designed CNC milling equipment from DATRON. Building on the success of the DATRON MLCube, which provides 3 m/s2 acceleration, advanced dynamics and jerk control, 0.1 micron resolution, and the ability to exercise up to 60,000 RPM across its 60“ by 40” work envelope, the MLCube LS makes the significant addition of an integrated linear scale system on X and Y axes.
To avoid the hurdles common to achieving tight accuracy across a large area, DATRON engineers have employed a unique combination of technologies that together present a robust and highly precise positioning system: the integrated measurement system. This integrated system marries the accuracy and repeatability advantages of the external linear scale, with the well-established and optimized mechanics of the ball screw-driven / linear guide axis. In the same way that unifying a servo motor with the associated ball screw by eliminating the drive belt, the ball screw/linear guide/linear scale system benefits in its operation and longevity overall by combining components and optimizing the system.
Benefits of Large Format Milling Machine MLCube:
Benefits if this unification are numerous, but in the case of the MLCube LS the most significant benefits show themselves where they matter most:
- System is free of wear or maintenance
- Highly resistant to contamination
- Exact positional measurement is achievable even under dynamic load changes
- Effects of thermal expansion are essentially eliminated
- Scale system is completely free of external influence by magnetic fields or electromagnetic vibration
- Positional accuracy is improved by 50% compared to the same machine without linear scales
But at the end of the day, the real question is: Why should I care about this machine? Well, fortunately, that’s the simple part:
With a starting price of just under $250,000 including typical options and a positional accuracy of ±25µ across nearly 17 square feet of workspace, the MLCube LS arguably offers the most capability, across the largest work envelope, with the highest degree of positional accuracy, for the least amount of money.
DATRON MLCube LS can be configured with a vacuum table or pneumatic clamping system to hold aluminum stock for parts like these.
So whether you need to produce a few very large and precise parts, or you need to batch machine hundreds of small precise parts in one long unattended machining session – the MLCube LS offers advantages that are not easily matched.