Step 9: Getting those Stepper Motors Running
No reason to go further till we can move motors!
Computer with 5 volt Printer port-
Load/Install MACH3 SW
Load install LazyCAM SW
Stepper control and driver boards
This SW talks to the printer port with pulses that tell the stepper electronics what direction and how far to rotate the motors. It has an excellent and proven track record in the CNC world. It also has a lot of variable/settings that can take a while to learn. Rather than post a tutorial on MACH3, please go to the Artsoft Web site as there as several great videos on setup for Mach3 and LazyCAM
To move you along, I will include my control file as it already has settings for the machine we’re building.
Steps for MACH3
1. Install MACH3 you should have rebooted after install as required.
2. Leave the stepper controller and motors off and disconnected for now
3. Open/run MACH3 and then simply close it
4. Download my Mach3Mill.xml file
5. Make a backup of your existing Mach3Mill.xml file
6. Copy the downloaded file over your existing Mach3Mill.xml located in the “C:\ Mach3 Directory
8. Run Mach3
9. If the reset button blinks, clk it
10. Go to Config/Ports-Pins/motor output and see the setting noted.
11. The DIR Low active and Step low active are the 2 items that may be different on your controller from mine. When we get to the motors, and they don’t turn, these are the settings to click/change.
12. My XML file is set for the ¼ 20 rods with a step division of 8
13. I have attached a simple part in gcode for the 3D Printer.
14. Download it and within MACH3 load it. You may need to change the extension, but M3 will read it.
15. You should see the part in the small graphic window.
16. Clk the ZERO X, ZERO Y, ZERO Z, ZERO 4 buttons
17. Clk the green Cycle start and the SW starts the process.
18. You’ll see the progress in the small upper right window, but it is slow as the machine must cut slow.
19. For visual effect, just keep clicking the FEED RATE + arrow to speed it up.
Not for actual part cutting!
Motors and Drivers
1. Hook up the motors to the driver boards first using the supplied board and motor documentation.
NOTE: Do not power the driver boards without a motor connected or they’ll be damaged.
2. Use a few buss bars to keep track of grounds and power.
3. Use an outlet strip with a switch to turn on the power supplies.
4. NOTE: Don’t assume anything on power supply polarities. Use the meter to measure and mark polarities.
5. Hook up the 7-9 volts to all boards as needed.
The 7-9 volts is just the low level circuitry power supply and draws less than an amp. Careful, a +5 volt power supply won’t work.
6. Hook up the 12 volt PS – Again, if you don’t have a single supply, then connect the grounds together of four supplies, but the + terminal only goes to a single driver board when there are individual boards. If you have a single board with all 4 axis, then you must use a single 12 volt 10+ amp power supply
some people use a old power supply from a computer. Do a search on this site for examples.
7. Connect a fully populated 25 pin printer cable from the computer to the control board.
8. Connect the interface cable from the control board to the four driver boards if you have individual boards.
9. With MACH3 running, turn on power.
10. The motors should lock/click.
11. You should NOT be able to turn the shaft with your fingers.
12. Place a sticky note paper on each shaft. (so you’ll see them turn)
13. Use the left, right, up, down arrow keys on the comp keyboard to rotate the X and Y motors
14. Use the page up and page down to rotate the Z motor
15. Use the numeric keypad + and – to rotate the 4th motor
16. If the 4th motor does not respond, go to config/system hotkeys and A/U++ to make the + key + and A/U—to make the – key reverse.
17. Again, if the motors do not move, you may need to click and change the signal polarity (direction) as noted above.
With motors running, you’ve won the biggest CNC/3D Printer battle.
This is the part that stops most people from building a CNC machine or Printer. Take your time and check your work before turning power “ON”. Believe me, it all gets easier from here! Even the 3D Printer is easier than this initial step.
In the photo, you'll see a roundish grey unit with a knob on top. This is an Auto-transformer that I use to vary speed of the cutting tool. You will need to reduce the speed of the cutter to cut plastic, but we'll use a light dimmer as we only need ~55volts at the cutter for plastic.