The DMC-III is a next generation professional desktop CNC milling machine.
*1 This micro-step controller was developed by ACT. We guarantee no lost-step errors in the normal operation. We have tested these machines at full speed (rapids rate) in all axes continuously for many hours at a time; the motors did not get hot at all, nor was there any loss of position. There are 5 processors in each controller: one for each of the three axes , one for the spindle motor control and one for the coordination of all motions. The electronic system is thoroughly tested subject to temperature variations and vibrations for reliability and lasting life. *2 Options to choose different size of motor with up to 50,000 RPM maximum speed. Any off shelf small spindle can also be easily installed in the machine. We can provide the custom made fixture to secure any spindle user preferred on the machine. *3 4th axis rotary table is a high precision table with zero backlash, 7.2 arc sec (0.002 degree) resolution.
1.1 Motion control Advanced "Bipolar sine wave" instead of "Bipolar Chopper" micro-step control algorithm is used to provide the optimal control for the step motors with no harmonic noises. This technology allows the stepper to move in micro precision without skipping pulse and remain in cool condition for many hours continuously running. The resolution for the each micro-step is 2 micron. The most common step motor is 200 steps (mechanical steps) per revolution. In order to have better resolutions for the step motor, it requires micro step controller to further divide each mechanical step. The most common technique using by all other manufacturer is the "Bipolar Chopper" technique. Bipolar chopper is to generate square waves in both directions to achieve half step, quarter step or one eight step resolutions. This number must be power of 2. Since the derivatives of the square wave are not smooth, it will also generate a lot of harmonic noises in the motor circuitry. These noises not only produce extra heat to the motor but also degrade the accuracy of the micro stepping and cause skipping pulse. However, "Bipolar Sine wave" is our company proprietary technology. We have spent 4 years research and development to finalize it. We divide each step into 10 micro steps which provides 2000 steps per revolution. This is equivalent to the most of high quality servo resolutions and reaches to the mechanical limits. We use extensive computer power to determine the exact voltage in sine wave and implement the accurate voltage and achieve the micro step motions. Since all the derivatives of the sine wave are smooth, it produces no harmonic noises. Therefore, it produces no extra heat to the step motor and guarantees 0.00008" (2 micron) resolutions. It is much better than the "Bipolar Chopper" technique using by all the other manufactures in the market. 1.2 Spindle control Light weight, high torque, variable speed, 1,500 to 12,000 rpm, brushless motors are used for the spindle driver. It is a small light weight but powerful motor. The motor has no brush to be worn out and can last long time. It is controlled by a sophistical digital control board. It senses the zero crossing of the back EMF in the circuit to determine the motor speed and uses PWM (Pulse Width Modulation) to control the timing of the firing sequence and interval to achieve the variable speed. The spindle speed can be controlled directly by the CNC software in the PC. No gears or no pulleys to be changed and no variable frequency driver (VFD) are needed. 1.3 Other features Integrated system with power supply, digital control and motor drivers into a single controller box and built-in to the machine. There are 5 CPU in each control unit to coordinate and optimize the motions for each axis to achieve the highly accurate motions (or cutting) in truly 3D or 4th axis. All axes are moving simultaneously in high precision. Built-in optic sensors in the control and motor drivers boards to protect the system in any overloading conditions. Modified Mach 3 CNC software with extensive graphic display and user friendly operation in the PC Window environment. All electronic parts are built by quality parts and minimize any possible down time. All PC board and the controller are thoroughly tested for vibration and temperature variations for lasting reliability.
1.1 Motion control
Advanced "Bipolar sine wave" instead of "Bipolar Chopper" micro-step control algorithm is used to provide the optimal control for the step motors with no harmonic noises. This technology allows the stepper to move in micro precision without skipping pulse and remain in cool condition for many hours continuously running. The resolution for the each micro-step is 2 micron. The most common step motor is 200 steps (mechanical steps) per revolution. In order to have better resolutions for the step motor, it requires micro step controller to further divide each mechanical step. The most common technique using by all other manufacturer is the "Bipolar Chopper" technique. Bipolar chopper is to generate square waves in both directions to achieve half step, quarter step or one eight step resolutions. This number must be power of 2. Since the derivatives of the square wave are not smooth, it will also generate a lot of harmonic noises in the motor circuitry. These noises not only produce extra heat to the motor but also degrade the accuracy of the micro stepping and cause skipping pulse. However, "Bipolar Sine wave" is our company proprietary technology. We have spent 4 years research and development to finalize it. We divide each step into 10 micro steps which provides 2000 steps per revolution. This is equivalent to the most of high quality servo resolutions and reaches to the mechanical limits. We use extensive computer power to determine the exact voltage in sine wave and implement the accurate voltage and achieve the micro step motions. Since all the derivatives of the sine wave are smooth, it produces no harmonic noises. Therefore, it produces no extra heat to the step motor and guarantees 0.00008" (2 micron) resolutions. It is much better than the "Bipolar Chopper" technique using by all the other manufactures in the market.
1.2 Spindle control
Light weight, high torque, variable speed, 1,500 to 12,000 rpm, brushless motors are used for the spindle driver. It is a small light weight but powerful motor. The motor has no brush to be worn out and can last long time. It is controlled by a sophistical digital control board. It senses the zero crossing of the back EMF in the circuit to determine the motor speed and uses PWM (Pulse Width Modulation) to control the timing of the firing sequence and interval to achieve the variable speed. The spindle speed can be controlled directly by the CNC software in the PC. No gears or no pulleys to be changed and no variable frequency driver (VFD) are needed.
1.3 Other features
Completed system integrated into a single piece machine weigh about 260 lbs which is movable by 2 persons without using forklift. Cast iron frame and T slot table provides rigidity and precision for all metals machining. Special designed clamp set to secure the work piece(s) directly on the T slot table for machining. No vises are required. Special designed work piece(s) holding devices for thin plate machining such as PC board drilling and electric panel machining. All parts are precision manufacture with final calibrations and alignment. The machine repeatability is 0.0001". High precision ball screw with zero backlash and the linear guided rails are used for all 3 axes. High quality ball bearings and thrust bearings are used for all 3 axes and the spindle. Light weight, high torque and variable speed (1,500 to 12,000 rpm) brushless DC motor is used for the spindle driver. No gears and pulleys to be changed. The spindle speed can be changed directly from CNC software in the PC. Belt and pulley system is used to isolate any vibration between the motor and the spindle. It provides mirror like machining surface.
Compact PC with installed Mach3 CNC software for the turnkey operation. The PC requires 25 pins parallel port with Window XP operation system. User can select to use their own PC if you are familiar with Mach3 software.
Standard ER11 spindle for tool bits up to 1/4" in diameter. User can choose from. ER11 is a smaller spindle with higher precision and higher manufacture cost. We offer the same price as ER16 spindle to our customer.
Standard ER16 spindle for tool bits up to 3/8" in diameter. User can choose from. We allow user to choose either ER11 or ER16 spindles for the same price.
Optional small high speed brushless digital motor drive M2 (2" diameter) for spindle driver. The motor speed is 1,000 to 12,000 rpm.
Small high speed motor,M2, connects to the spindle through pulleys and belt. The gear ratio from motor to the spindle is 2 for ER11. Therefore, it provides 24,000 rpm for ER11 spindle maximum speed.
Standard high torque motor, M3 (3" diameter) connect to spindle through pulleys and belt. The standard M3 motor speed is 1,000 to 6,000 rpm. The gear ratio from motor to the spindle is 2 for both ER16 and ER11. Therefore, it provides the maximum speed of 12,000 RPM for both ER16 and ER11.
Large precision T slot table built by cast iron for precision and rigidity. It provides large working space with the simple operation instructions posting on the table for users convenience.
This is the most advanced digital controller for all 3 axes and the spindle motor speed control integrated into a single box. The dimension of the box is 22" X 7" X 3.5". There are 5 CPU micro-process chips inside to achieve 2 micron motion precision and the variable spindle speed. We have spent 4 years to optimize and finalize this product through thoroughly tested. The regular power supply (120V or 240V) is used. This controller box is integrated with the machine into a single piece of the machine. No any additional box need to be connected to the machine except the PC. please refer to the technologies page for the details.We guarantee the product for lasting life.
High precision (0.00008") infra rate optic sensors are used for home switches for all axes. This is a non contact sensor which can provide precision and reliability for many years.
The emergency stop button on the machine to shut down the system.
Showing the input ports for DMC-III machine controller box: a 25 pins parallel port (printer port) for the PC, 4th axis port which can also be used for the tool sensor or digitizer inputs and Aux port for the liquid cooling pump system.
4 heavy duty handle bars provided to bolt on the machine for easily moving.
Custom made fixture to secure any spindle user choose, such as NSK 50,000 rpm spindle, to the DMC-III machine.
Optional item to install liquid coolant pump system. The coolant pump on and off is controlled through CNC program.
The machine is bolted on a wooden pallet for shipping.
The complete package, includes PC, tool box, clamp sets, colletes for turnkey system DMC-III is shipped in a wooden crate, dimension 33" X 24" X 36" (WxDxH), and total weight about 375 lbs. To unpack the crate, please remove the screws on the bottom of the crate and the entire top portion can come out as shown in the previous picture. The wooden crate is reusable for the future shipment.
