Base Y Axis X Axis Z Axis

Base Table Specifications: Table Work Area: 1160 in 2 Maximum Part Weight: +18 lbs Table Supported by Rail: in x 1 in Y-Axis Rail Design: Length: 38 in Weight Supported: 40 lbs Length and Weight was significant Guide system selected: Supported rail Y Axis

X Axis Designed Considerations: 5.5 lb cutting force 10 lb tool head 100 lb.in moment due to weight 75 lb.in moment due to cutting force Design Specifications: X-Rod Diameter: 1.18 in (30mm) Rod Spacing: 4 in Supports 37.8 lbs/rod Maximum deflection: in System Loads: lbs, lbs, lbs Alternative Design: 4 Rods with lbs/rod Rod Diameter : 1 in Cost increases x Rod 1: Rod 2: y Rod 3: 22.53

Z Axis Z-Axis Design Considerations: Minimize moment about x-axis ballscrew Guide system selected: Versa rails Moves tool head closer to center of x-axis Alternative Design: 2 Guide Rods Increases moment

Ballscrew Drive Specifications: Lead: 0.2 in/rev Diameter: 5/8 in Supports: Ball bearing & Thrust bearing block assembly Thrust Forces: Acceleration 28.9 lbs -Static friction and acceleration force Constant Velocity 18.8 lbs -Only kinetic friction

Tool Head Options: Spindle Paste dispenser

Motor Drive Assembly Purpose: Power Motors to drive ballscrews, providing motion in 3 dimensions

Motor Design Requirements Provide a minimum 20oz.in of torque at a speed of 4 in/sec. Required to move each axis. Be cable of providing a minimum torque safety factor of 100%.

Motor Specifications Motor sizes: 276 oz.in (X-axis & Y-axis) 166 oz.in (Z-axis) Motor Requirements: 2.8 amps/phase Voltage of approx. 48 volts for a torque of 80oz.in at 4in/sec.

Motor Driver Considerations Requirements: step and direction inputs to move motors Cable of driving motors at a minimum of 2.8 amps. Surface mount chips to save space. Selected: Allegro A3986 [micro-stepping sequencer]

Motor Driver Considerations Other design requirements Low power dissipation: Mosfet H-Bridge with very low on resistance. (.050 ohm) Current sense resistor: very low resistance (.043 ohms) Traces :2 oz vs. 1 oz copper. – To Provide low trace inductance to reduce high voltage spikes from destroying chips. Provide low power dissipation for motor traces. Power Transformer selection: provide power to motors that would fit into small cabinet with minimum stray magnet fields. System monitoring and fault identification: fuses and LEDs added to aid trouble shooting and protect circuit

Features Pulse width modulation, MOSFET H-Bridge Motor size from 2 to 4.7 amps Optical Isolation for all inputs Full, Half, 1/4, 1/16 step resolution Over Current Protection Over temperature and under voltage protection Fuse Blown Indicators (3 LED’s) 5 V supply Good LED Outputs to Controller Drive Board Ready Signal Drive Board Fault Signal Motor Power Supply Ready Signal

Ethernet Microprocessor ENC624J600 (Microchip Technology) Communication Controller PIC24FJ256GB110 (Microchip Technology) Motion Controller PIC24HJ256GP610 (Microchip Technology) PIC24HJ256GP610 PIC24FJ256GB110 ENC624J600

24 bit 100 pin micro-processor is used to control the communications for the CNC. Any data that comes into the the Controller board goes thorough the Communication micro controller. Specific requirements: 1 – SPI 2 – UART 8 – Data Pins 16 – Address Pins Connections to the Com controller: RS232 Serial USB to Go Ethernet VGA(Output)

64 pin micro-controller specifically for Ethernet implementation. No programming was needed for this chip. It comes pre-configured to take Ethernet data. This micro chip connects directly to the Com Controller Specific Requirements: 1 – SPI External Connections: RJ45 Connector

24 bit micro-controller used to take the data from the communication micro chip and distribute Data to the motor driver board. Specific Requirements: 2 – SPI (to communication) 1 – UART (to Pendent) 8 – Data Input Pins 4 – External Interrupts

Case Screen

Requirements – LCD Screen – Four buttons for accessing different function screens, accepting a command, canceling a command, and switching the axis between y and z on up and down directional buttons – Four buttons to change direction on x, y, or z axes – Feed pot dial to increase or decrease feed/speed rates

Casing – Upper section will have a width of 5 inches and a length of around 2.5 inches Placement for LCD Screen, Function button, Accept Button, Cancel Button, Axis Switch Button, and Feed Pot Override – Lower section will have a width 3 inches and a length of 3.5 inches Placement for X, Y, and Z directional buttons

System Diagram – LCD Screen – PIC 24 Microcontroller – DB9 and MAX32 Receive and transmit information from main controller system to pendant system – Voltage Regulator Input of 5 volts to make controlled output of 3.3 volts – Feed pot/Potentiometer Control of feed/speed rate – Clock chip Steady, constant flow of information – Switch buttons

PCB Layout – Top Layer LCD Screen Top four buttons are function, accept, cancel, and axis switch Bottom four buttons are four axis direction movement – Left and right control x axis – Top and bottom control y or z axes – Bottom Layer Remaining Components Tightly packed to prevent losses Connector at bottom to attach to main controller system

Screens – Main Screen Upper left box contains current x, y, z, and acceleration axes Lower left box contains circles for limit switches which will either be red/green to show on/off Upper right box contains current adjustment of feed pot ranging from % of the rated value Lower right box displays the current state of the machine which can be jog, idle, or run – Other Screens All Sub Screens Offsets Screens- Home, Park, Work Offset 1, Work Offset 2 Soft Limits Screens- Upper and Lower Parameters Screens- Machine Parameters, TCP/IP Configuration, Communications Port Flash Drive Screen

Mechanical Total$ 2, Electrical Total$ Grand Total$ 3, The Mechanical Total comprises of: Frame Bolts Ballscrews Rods Shafts The Electrical Total comprises of: Circuit Chips Driver Boards Controller Boards Pendent

Step #Step DescriptionHours 1Place parts on boards4 2Table Assembly20 3Gantry Assembly15 4Tapping and Drilling13 5Electric Box Assembly8 6Assemble Systems4 7Testing5 Total Hours69 Each component requires different time frames to finish each subassembly. The construction is simple once all subassemblies are finished, and the machine can be fully assembled in a 4 hour period with a three man team. The machine is ready for operation after testing is complete.

Dr. Haibo Wang- Faculty Technical Advisor Mr. Mark Hopkins- Technician/ Field Engineer for Allegro Micro-devices Mr. Howard Everton- President of Norva Plastics Barb Saathoff- Representative from Dytronix Tim Attig- Mechanical Shop Machinist