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CNC Electronics - Stepper Drivers, Motors, Power and more...

Here are the electronics that you will need to make the CNC Router move! I am offering a bundle of components as shown below. This equipment will have the power for the CNC router kits that I offer on the main sales page. This system will also enable many other CNC retrofits.

CNC Electronics Combinations

Here are a few popular combinations of stepping motors and drivers, including breakout board and power.

3 Axis Electronics Combo
(3) 425 oz-in stepping motors
(3) Drivers (3.0Amp 24-40 Volts, 1-1/64 microstepping)
(1) 36v 8.8a Power Supply
(1) Breakout board

4 Axis Electronics Combo

(4) 425 oz-in stepping motors
(4) Drivers (3.0Amp 24-40 Volts, 1-1/64 microstepping)
(1) 36v 8.8a Power Supply
(1) Breakout board

3 Axis Electronics Combo (For Heavy Gantry)

(2) 425 oz-in stepping motors
(2) Drivers (3.0Amp 24-40 Volts, 1-1/64 microstepping)
(1) 651 oz-in stepping motor
(1) Driver (6.0Amp 24-70 Volts, 1/2-1/256 microstepping)
(1) 36v 8.8a Power Supply
(1) Breakout board

3 Axis Electronics Combo (All Large Motors)

(3) 651 oz-in large stepping motors
(3) Drivers (6.0Amp 24-70 Volts, 1/2-1/256 microstepping)
(1) 36v 8.8a Power Supply
(1) Breakout board

A la carte:


Power Supplies

You will need a power supply to power up stepping motors and drivers.

Power Supply (36 Volts and 8.8 amps)
Power Supply (24 Volts and 8.3 amps)

Stepping Motors (Also called Stepper Motors)

This is the thing that actually turns and provides movement to the machine, but don't forget the driver that makes "this" thing work.

Motor (425 oz-in 1/4" dual shaft) - Datasheet for wiring specifications
Motor (651 oz-in 1/2" dual shaft) Datasheet

Stepping Motor Driver (Aslo called Stepper Driver)

You'll need this to make the Stepping Motor to work. This incredible piece of electronics translates a pulse into a high powered complex coil firing combination.

Motor Driver (24-40 volts DC, up to 3.0 amps, microstepping from 1 to 1/64) - Datasheet
Motor Driver (24-70 volts DC, up to 6.0 amps, microstepping from 1/2 to 1/256) - Datasheet

2.5 Amp Stepping Motor Driver

This stepping motor driver plugs conveniently into the 3D Printer main board. No cables from the main board to this board is necessary.

Breakout Boards

Breakout boards are the interface from the computer to the drivers. We offer two varieties of breakout boards.

Breakout Board (with relay and up to 5 axes)
Breakout Board (standard up to 4 axes but contains more input capability) Datasheet

3D Printer Main Board

This board plugs into the Arduino Mega 2560 and provides connections to the stepping motor drivers, end stops, RS-485, a ribbon connector for other functions, and a simple 12 volt terminal.


Arduino Mega 2560: $64.00

This board becomes the brain of the 3D Printer and serves as the main interface to the computer.

E-Stop (Emergency Stop) Button - 120v-10A/240v-6A

If your CNC Machine starts to run wild, or decides to destroy itself, this button could save you machine, and your nerves! This button is capable of NC (Normally Closed - red side) and NO (Normally Open - green side) operation (notice the red and green on the bottom of the button). Push the button in to engage, and twist to release.

Limit Switch

Limit switches serve as the mechanism that tells the computer the limits of the CNC machine. When one of the axes moves to an axis limit, the switch is activated and the machine stops. These limit switches are also use to inform the computer of the home position. Typically, 6 of these switches are needed, two per axis.

Single Limit Switch
6-pack

End Stop (Limit Switch)

This is a snap action switch and a little debounce circuit along for the ride. The board includes a convenient header and an LED to show its state.

20 AWG Cable - Multiple Conductors

This cable is typically used for motor wiring from the drivers to the stepping motors. There are multiple wires within the gray jacket (called conductors). The number of conductors labeled is the number of wires minus one wire, so the following will be labeled with number of wires, not number of conductors. Specs: Unshielded, stranded copper, PVC jacket material, meets CSA/CE/UL specifications, standard flex (great for use in motion applications). The individual wire insulation has the conductor number labeled so color coding is not necessary. Here is a handy link to learn about wire gauges and current handling capacity

4 Wire Cable
8 Wire Cable

Parallel Cable

This is the cable that carries the signals from the computer to the CNC electronics. If there is a 25 pin female port on the back of your computer, then this may be the cable for you. Features: Direct through connection for each pin, shielded, 6.56 feet long (2.0 Meters), beige color, lead free and RoHS compliant.

DB25 Male to DB25 Male Parallel Cable
DB25 Male to DB25 Female Parallel Cable

Breakout Boards: One of the most important components included is the breakout board. This little gem allows you to interface your computer, using the parallel port, with up to four (4) stepper drivers. Equipped with all of the wire connectors, integrated circuits for interfacing and signal processing, and resistors to protect your computer from any damage, this will keep you CNCing without a hitch.

Drivers: Will translate the signals to what the stepper motors will understand, and amplify the translated signals to turn the motors. As you can see, there are loads of information silk screened on to the case for easy wiring. That funny looking striped metal piece is for heat dissipation, since these driver chips can get hot. Specifically, these drivers will be able to accept 24 to 40 volts with current up to 3 amps. Think of amps as the muscle and volts as how fast the muscle can be brought into the motors. These also enable microstepping at half, quarter, fifth, eight, tenth, 1/25, 1/32, 1/50, 1/64, 1/100, 1/128, 1/200 and 1/256 (whew, that was tiring). It even has protection circuitry within for overheating, over voltage and over current. there are dip switches for easy current switching and this driver will accept 4, 6 or 8 lead motors. Oh yeah, the most important thing, thiese puppies have idle current reduction.

Stepping Motors: Provide the linear motion. When the driver sends a combination of current to the coils of the motors, it will turn 1.8 degrees, or tighter depending on the microstep setting on the drivers. That is, if you have half step, then the shaft will turn .9 degrees per step, quarter step .45 degrees per step, and so on and so on... These are NEMA 24 motors (standards terminology which only refers to its faceplate specifications and measurements), but don't let the size fool you, these motors can hold at 382 oz-in or 425 oz-in of torque (depending on availability). The current rating is 2.8 amps and 4.17 volts, so you will need a power supply that can be drawn at 8.4 amps, which is a nice segway to the power supply.

Shaft sizes for the NEMA 24 are 1/4" and NEMA 34 are 1/2", typically.

Wiring diagram: Wiring diagram for 3-axis using the standard breakout board

Troubleshooting Tips:

If the motors are not turning, and you are wondering why? Below is a few simple steps you can take to localize the issue. These steps assume that you have Mach3 or another control software installed and the interface requires a parallel cable.

1. To determine if there is a signal coming out of your computer, you will need to probe the port on the back of the computer and jog to see if the voltage changes. You will need a multimeter. Test each pin that you set as output. If no signal, it is a software or computer problem.

2. If there is a signal at the port, plug in the parallel cable and test the other end to see if the cable is showing output. if not, the cable is bad.

3. If there is a signal from the parallel port, probe the respective pins on the breakout board, if not, then the breakout board may not be configured properly (jumpers).

4. If there is a signal, you are half way there. Then we will need to check the drivers.


Here is a great guide that was developed by one of my customers, David W, as he was troubleshooting his own electronics:

Trouble shooting - Build your CNC - diagnostic - motors won't /don't work

This is one trouble-shooting guide to the Blacktoe CNC table based on my experience. It begins at the point when you have followed all of the instructional materials to build the table, installed Mach3 on a desktop PC, configured the motors, plugged in the parallel cable, tried to jog one of the axises... and gotten nothing. It is also assumes that you have a multimeter and the basic tools. Here are some additional resources that you will probably want to read before you get started:

Mach 3 documentation: http://www.machsupport.com/documentation.php

Here we go:

1. Before we start properly, if you haven't already, disengage the transmissions by taking the chains off the sprockets to avoid an un-expected movement that might damage you or your machine. Also, be sure you don't electrocute yourself either -- unplug the logic system when you are working in the wiring (and be careful when you are testing). Disconnect your parallel cable for now (as long as you are at it, make sure you have the right cable -- you need a Straight Thru Serial DB25M/DB25M like this one [ http://www.amazon.com/Belkin-25ft-Straight-Serial-DB25M/dp/B00004Z5W7 ]). Also, restart your machine just to make sure you are starting fresh.

2. Download, install and start up a parallel port monitor:

http://www.geekhideout.com/parmon.shtml

This will give you immediate feedback on which pins are conducting at hi and lo voltages. Remember: "In TTL circuits, any voltage between 0 and 0.8 volts is called "lo" and any voltage between 2.4 and 5 volts is called "hi"."

3. Double-check your "Ports and Pins" configuration.

In Config/Ports and Pins/Motor Output you want these values:

X, Y and Z set to Enabled

X, Y and Z set to Step Low Active

X-axis: Step Pin #: 2
X-axis: Dir Pin #: 3
Y-axis: Step Pin #: 4
Y-axis: Dir Pin #: 5
Z-axis: Step Pin #: 6
Z-axis: Dir Pin #: 7

4. Go into Config/Ports and Pins/Input Signals/EStop and click on "Active Low". Mach 3 cannot disable the EStop, so this will "reverse" the emergency stop to inactive on a lo signal (such as when the plug is disconnected). You will click this setting on and off several times during trouble-shooting as you connect and disconnect the port cable, so get to know it:

Active Lo for when the cable is disconnected
Active Hi for when the cable is connected

5. In the Program Run screen, jog the X-axis a few times back and forth while looking at the parallel monitor. You should be able to jog the X and Y axis by hitting the arrow keys on your keyboard, but if you hit the Tab button, you can bring up a jogging sub-screen that will let you jog it with the mouse. Note the location and colors of the pins on the top right corner of the array (pins 1 through 7) and how they change when you change direction. Note that pins 3, 5 and 7 will change from Lo to Hi when you alternate directions.

Red = Hi Signal (2.4 - 5.0 Volts)
Green = Lo Signal (0.0 - 0.8 Volts)

6. Confirm these values by testing the parallel port connection in back of your PC. You will need to look closely to find the pin numbers on your port because they are printed very small, but they should be back there. Insert the black probe into the #1 Pin (should be Lo) and probe each successive pin (2-7) with the red probe. Do the voltages correspond to the values being reported by the parallel port monitor? In my case, the Lo signal was 0.0 - 0.1 Volts and the hi signal was 3.3 Volts. Change directions a few times to confirm. If not, your problem lies before the parallel port output from your PC.

7. Now connect the parallel port cable to the back of your PC *but not your breakout board yet*. Re-test the voltages at the end of the cable the same way you tested them in back of the PC. It will be a bit trickier this time because you have to contact the pins instead of letting the probe be held in the holes, but it's manageable. Are you getting the appropriate voltage readings? If not, you might have a bad/wrong cable.

8. Now you can plug the parallel cable into the breakout board again and plug in the breakout board and driver power supplies -- there should be LED lights lit up on every component. You will notice that Mach 3 will go into EStop mode because you now have a hi signal going to the PC, so go back into Config/Ports and Pins/Input Signals/EStop and toggle off "Active Low". Hit the reset button and try jogging the X-axis a few times. If nothing happens, move onto the next step.

9. Check the power-supply wiring to the breakout board. Is the light on? If not you might have your circuit reversed. Is there a loop running from the 5V power supply to the "EN" pin on the board? If not your board is not engaged. Test it by placing the red probe on the 5V pin and black probe on the #2-7 output pins. If your board is engaged properly, the Hi signal output should be about 5.5 Volts (note the increase in voltage). If it is not engaged, it will be running about 1.5 Volts on each pin.

While this is by no means a comprehensive trouble-shooting guide, it should help you isolate any issues you might be having in your system and hopefully get you started a little sooner.

Good luck!

Products


Machine Kits and Plans Motion Electronics: Motors, Drivers, Power and More Bearings for Lead Screws and Linear Motion Couplings to connect motor shafts to lead screws Router Accessories End Mills Mechanical Parts