High Performance Servo System
The Control has two main improvements that directly impact servo system performance: 1) higher motor resolution and 2) faster servo response time. High motor resolution improves programmability for both input and outputs across the board, even in Jog, and provides better finishes and accuracy. Add in a faster servo response time – 16x faster in fact – and you have a high performance servo system.
AC Motor Resolution
The Legacy, as with most controls, has a best case minimum resolution of .0001″ with the proper motor hardware. With AC motors, the Control has a minimum resolution of  .00001″ or 10x the resolution.
DC Motor Resolution
The Legacy has a best case minimum resolution of .0001″ with the proper motor hardware. With DC motors, the Control has a minimum resolution of .00005″ or 2x the resolution.
Servo Response Time

The heart of the NXGEN servo system is the motion control board. The control board uses a high-speed RISC-processor which has a servo response time of 0.062 ms (16 kHz) — 16x faster than the Legacy servo controllers. This speed greatly increases the servo reaction time.

The difference is even audible. For example, on any machine with the Legacy control paired with Glentek brushless motors and amplifiers, the servos generate a “whining” buzz when not in motion. Now with our control, using the same servos, that “whine” is significantly reduced, in fact almost gone.

Servo Stiffness

The inability to move to or hold position under load (weight/mass and cutting force) is measured as “following error” from the required position. A motor overload alarm occurs when this error becomes too large. In one test, to demonstrate the improved stiffness, we performed a static torque test. The test compared the original Legacy servo control board with the NXGEN system, using the same brushless motors and amplifiers while applying a 20 inch pound load at the motor shaft. The Legacy control measured .0004″ position deflection. With the NXGEN control, we measured only .0000125” deflection.


Servo stiffness directly relates to the ability of the servos to accurately control the machine slides while standing still or during motion resulting in more accurate and better finishes.

Servo Stability – Zero Following Error

Having a higher stiffness is one of the features that enables us to achieve a true zero following error. The combined features previously described 10X Resolution, 30X Servo Stiffness and 16X Faster Servo Response, enable the motion control to significantly reduce following error. In most cases the servo system operation has zero following error. Without the normal servo lag as with most machines, now your parts will be consistently more accurate, even as you speed up the feed rates. Our goal is reducing your part cycle time without sacrificing accuracy.

While others worry about saving seconds during tool change time, we look to saving all the minutes during machining time!


Normally with CNC controls, you will see the position “dither” back and forth +-.0001” while “servoing” to hold position. With our new designs, using the standard AC motors, our Control achieves a stability of +-.000010, a factor of 10x better!

iSMOOTH – Intelligent Smooth Servo Motion
Smooth Acceleration and Deceleration makes it much simpler to maximize performance and reduce part time without damaging the machine. With our newly developed iSMOOTH servo control, we can ramp up/down, during multiple moves, regardless of the number and size of the moves.

This velocity graph shows in red the acceleration taking place while making N1,N2 and N3 moves, then decelerating N3,N4 and N5 moves. This results in a smoother velocity during acceleration and deceleration as shown above. Even during G8 mode with ramping turned off, changes in velocity are automatically ramped up or down to maintain smooth motion regardless of the move length or feed rate. It automatically maintains the proper acceleration and deceleration profiles.

With the Legacy and most other controls, in G9 ramp mode, the machine would “bang” during a starting move or stopping move (N1 and N5). The G9 ramp was limited to one move and was especially a problem with small moves when a longer ramp is more desirable. This was also the case when applying a change in velocity that requires ramping during profile motion.
Using the latest advanced velocity algorithms reduces the “bumps and bangs” for G1, G2 and G3 feed moves as well as with rapid moves. The velocity ramp profiles are selectable and adjustable on-the-fly. While other high end controls might have similar features, most are very complicated and almost impossible to use, we strive to make it as easy as possible. As such, this feature has only two settings: ON/OFF and what velocity ramp to apply.
NURBS Interpolation*
Non-Uniform Rational B-Splines provide free-form surface machining more integrated to the CAD system instead of line segment limitations. NURBS retains the closest possible mathematical definitions of the part, providing better accuracy and smoother reproduction of the CAD surface. No longer are you restrained to using only XYZ data points with a typical .0001″ rounding limitations.
*NURBS is available as an option only. Inquire for more information.
Accuracy has a direct relationship to surface finish. Improving the part finish reduces any required hand polishing.  That’s less cost for you.
High Speed Block Processing

The ability to process small moves and not become buffer bound, causing the machine to pause or stop, is termed “Block Per Second Throughput” and it is measured by how many moves the control can process within one second. With the Legacy control, the fastest speed was 250 blocks per second in G90, 1000 blocks per second in G91.1 mode. With the NXGEN, we have three modes for Advanced Surfacing: No Ramps, Buffer, and High Speed.

Standard Speed

The 511 block look-ahead with motion data pre-buffering increases the processing time up to 1900 blocks/second. The Legacy’s performance averaged at 250 blocks/second (depending on hardware and year), making the NXGEN perform 7.6x faster on average.

High Speed (Option)

The Legacy’s maximum processing speed was using the command G91.1 for high speed incremental moves at a speed of 1000 blocks/second. The NXGEN has a high speed optional mode of 5000 blocks/second. That’s 5x times faster than the Legacy G91.1 or 20x faster than the average speed of 250 blocks/second.

iRAMP – Intelligent Feed Forward Ramp Control

Automatically accelerate and decelerate before interpolation. The iRAMP control feature uses a 511 block look-ahead buffer to determine when it needs to slow down for a direction change. The look-ahead will automatically generate at G9 ramp when needed then switch back to G8 mode. Simple to use, simply turn it on or off in the middle of the program or modify settings on-the-fly.

This diagram shows red dots where the control would automatically generate a ramp. This allows maximum high speed machining to be easily achieved by automatically ramping without slamming to a stop and banging at the start. The programmer is relieved from the normal complication of adding G9 and G8 in the program.

The iRAMP feature allows increasing feedrates without concern of excessive “slamming” into corners and thus reducing the cycle times without damaging the machine.

Spline Interpolation

Create a Bi-Cubic Parametric Spline through original programmed points and use less data points (linear moves) to achieve a smooth finish.  The motion control board interpolates in-between the original programmed points as it cuts the part. Requiring less linear moves simplifies the programming while actually providing the best possible finish.
The diagram below shows typical shape before and after the Smoothing function.

See these results for yourself