This is a follow up to the Easy to Build Desk Top 3 Axis CNC Milling Machine Once you get the machine all put together its time to make it go.
So it's time to drive the motors. And here I've put together a circuit that I think is the absolute cheapest and easiest way to control stepper motors with step and direction signals. It works with many of the free or low cost softwares that produce step and direction signals through the parallel printer port. I'll explain how it works but for those of you who just want to get on with it... The_Next_Step
But I would suggest for those of you who are unfamiliar with circuits to do it on a bread board (see pictures). This way you can easly correct any mistakes and try different things.
This schematic is just to control one motor so for the milling machine you need 3 of these circuits and 3 motors.
From Left to right and top to bottom. I try to draw schematics so that positive voltages are toward the top and ground or negative volge is toward the bottom. Inputs are to the left and outputs to the right. Fist off the voltage that you are going to use to run the motor needs to be stepped down and regulated for the logic chips. I used a 6.2 volt Zener to do this because it's low enought for the logic chips to receive the signals from your printer port and high enough for the outputs to drive many of the standard power FETs, so you may not have to use logic FETs like the schematic shows. So the resistor R1 drops the voltage, the Zener diode regulates it to 6.2 volts and the capacitor C1 filters out any noise from the motor, and this voltage powers the two IC's.
The first IC (CD4516) is called an up/down counter. One signal from the printer port will tell the counter if it will count up or down and the other signal, called step, will increment or decrement the counter by one count. Now were only going to use two outputs from the counter Q1 and Q2. With this binary counting method there are only 4 combinations of output from the counter: 00, 01, 10, and 11. These lines are fed to the A and B inputs of the other IC (CD4028) which decodes these combinations to 4 seprate outputs.
I did a trick here using the C input to work as an Enable input. If the Enable(optional) is connected to the parallel port and the computor tells it to shut off all of the outputs to the FETs will go low(Off). So the four outputs of the decoder drive the FET transistors and the FETs drive the four poles of the motor.
Now everybody wants to know what the light bulb is for. Its not so much whether you use a bulb or a resistor, its that a bulb comes with a socket. You can get these wedge base light bulbs from 1 watt to 20 watts. Start with may be a 4 watt bulb and if you find you need a little more beef you just pull it out and put in a 10 watt bulb. It's really handy. And I found it's good to have some voltage drop there as kind of a ballast for the motor windings. The diodes catch some of the current that comes out of the motor each time the FET transistors turn off. The diode feeds this current back to the supply.
When you get the circuit up and running find a power supply that puts out more voltage than you really need and then change out light bulbs till you get it running smoothly. Some of my stepper motors are 5 or 6 volt and some are 12 volt but it all works out.
So it's time to drive the motors. And here I've put together a circuit that I think is the absolute cheapest and easiest way to control stepper motors with step and direction signals. It works with many of the free or low cost softwares that produce step and direction signals through the parallel printer port. I'll explain how it works but for those of you who just want to get on with it... The_Next_Step
But I would suggest for those of you who are unfamiliar with circuits to do it on a bread board (see pictures). This way you can easly correct any mistakes and try different things.
This schematic is just to control one motor so for the milling machine you need 3 of these circuits and 3 motors.
From Left to right and top to bottom. I try to draw schematics so that positive voltages are toward the top and ground or negative volge is toward the bottom. Inputs are to the left and outputs to the right. Fist off the voltage that you are going to use to run the motor needs to be stepped down and regulated for the logic chips. I used a 6.2 volt Zener to do this because it's low enought for the logic chips to receive the signals from your printer port and high enough for the outputs to drive many of the standard power FETs, so you may not have to use logic FETs like the schematic shows. So the resistor R1 drops the voltage, the Zener diode regulates it to 6.2 volts and the capacitor C1 filters out any noise from the motor, and this voltage powers the two IC's.
The first IC (CD4516) is called an up/down counter. One signal from the printer port will tell the counter if it will count up or down and the other signal, called step, will increment or decrement the counter by one count. Now were only going to use two outputs from the counter Q1 and Q2. With this binary counting method there are only 4 combinations of output from the counter: 00, 01, 10, and 11. These lines are fed to the A and B inputs of the other IC (CD4028) which decodes these combinations to 4 seprate outputs.
I did a trick here using the C input to work as an Enable input. If the Enable(optional) is connected to the parallel port and the computor tells it to shut off all of the outputs to the FETs will go low(Off). So the four outputs of the decoder drive the FET transistors and the FETs drive the four poles of the motor.
Now everybody wants to know what the light bulb is for. Its not so much whether you use a bulb or a resistor, its that a bulb comes with a socket. You can get these wedge base light bulbs from 1 watt to 20 watts. Start with may be a 4 watt bulb and if you find you need a little more beef you just pull it out and put in a 10 watt bulb. It's really handy. And I found it's good to have some voltage drop there as kind of a ballast for the motor windings. The diodes catch some of the current that comes out of the motor each time the FET transistors turn off. The diode feeds this current back to the supply.
When you get the circuit up and running find a power supply that puts out more voltage than you really need and then change out light bulbs till you get it running smoothly. Some of my stepper motors are 5 or 6 volt and some are 12 volt but it all works out.
Remove these ads by
Signing UpStep 1: The Circuit Board of Appeals
OK here's what your all looking for. I made a simple PC board layout that includes 3 motor driver circuits connected to a 25 pin D sub Parallel printer port connector. Here's a picture of the layout. At the top of the picture you see a place for a voltage regulator. You can use that or you can put a resistor and Zener Diode in its place(like the schematic shows). On the right edge is a place for the 25 pin D-sub connector that connects to the parallel printer port. You just jam the PC board between the two rows of pins and solder it.
On the left side are places for the lamp sockets. You need to look over the schematic to see where some of the parts go but it's all there.
On the left side are places for the lamp sockets. You need to look over the schematic to see where some of the parts go but it's all there.
Visit Our Store »
Go Pro Today »
Small error in Port Setup printscreen of Tom.
Option 1: set pin 14 Reverse = True (instead of False)
Option 2: set pin 4, 7 and 14 on NU (as Enable is optional). You can than use pins 4,7 and 14 (reverse=true) for something else.
See pictures.
Regards,
Dirk
Could be done.
What software and mechanics will you use ?
Regards,
Dirk
I've looked further and in KCam4 you can only connect 4 motors.
X, Y, Z and A.
And yo have to check if there are pins available on your parallel-port
Pins 1, 16 and 17 are available in the KCam4 software but you have to check if they are hardware available.
Also you have to check if Pronterface is capable of stearing your motors via the parallelport AND via pins (not bit's = processor needed).
This last one can be probably done by exporting to KCam4 and use KCam4 for driving your motors.
Why you need 5 motors ?
X, Y, Z = OK, the spindle you can mis-use to control the fluidwire.
Therefore you need 4 outputs.
Regards,
Dirk
Just tested the following:
Tom has foreseen pins 4, 7 and 14 as pen-enable (optional).
If you put NU in the port-setup of KCam4 in the place where you could enter 4, 7 and 14 everything is still working (because of the flag Motor Enable --> Always On).
Therefore you can use pins 4,7 and 14 (wrong IO-address in KCam4 !!!, &H37A instead of &H378) to control your 4th motor.
Succes,
Dirk
What is the brand and type of the 3D printer ?
So I can see more specs.
A 3D printer is probably just a bunch of steppermotors which work with special software (like e.g. Pronterface).
Is a bit a X-Y-Z-milling machine but with a fluid instead of a spindle with drill ?? Or am I wrong ???
Regards,
Dirk
Regards,
Dirk
The bulbs mentioned are simple car or bicycle ones.
Depends on the powersupply voltage.
Regards,
Dirk
i use 60n06 as mosfet
stepper motor 4.6A
i use power supply 17v
i make limitation circuit for current
but i have two problem
1- 60n06 Heated so much i put heatsink but nothing change
2- voltage across motor is only 1.4v
i don't know why
i use 17v supply voltage
please help
Your ic's should have 3V -> 5V input to work (see datasheet).
If not, check your power supply and part R1 (resistor 1K).
Regards,
Dirk
how powerful are the steppers?
Depends on the motors and powersupply, not the circuit.
Regards,
Dirk
Thank you
+ from the pcb to lamp 2, mass from lamp 2 to motor 2.
....
Do not want to be smart and put all together.. does not work !!! Tried this before :-(
So you need: 3 x 5 wires per motor + 2 for the spindle = 17 wires.
Regards,
Dirk
firstly thanks for your Instructables.
have built the stepper control your design rev 2/11/07...cheep stepper. CD4516 and CD4028.
have built two boards so far.
for both boards, on slow clock test runs fine in forward, but misses Q4 output on the CD4028 every 2nd pass in reverse (tested with LED's) ie: direction to ground.
Apart from this every thing else works ok.
have You come across this before ? , if so, what is the cause / fix.
Regards
Doug
Already replaced the CD4028 ?
Also checked the pcb ?
Re-tip the solderpads whith your solderpin.
Perhaps a very small mistake ?
Regards,
Dirk
Mostly 37xBh.
This must be the same as in KCam4.
Regards,
Dirk
KCam4 just puts pin's high/low. That's all.
The high/low's are translated to on/off trought the fet's.
No programming involved.
Simple.
Regards,
Dirk
THANKS, ED
Use the RFP12N10L Fet's.
Perfect for the job.
Regards,
Dirk
Otherwise (perhaps already) you may crash the motors.
As Tom mentioned,use a simple powersupply (3 - 4,5 - 5 - 6 - 7,5 - 9 - 12) Volt switchable.
Regards,
Dirk
Attached a sketch with markups.
Thanks in advance.
regards,
sanjay
You mixed up the R1 (1K resistor) with C6 (capacitor 220uF).
Regards,
Dirk
No.: 57BYGH420
Frame Size: NEMA23
Step Angle: 1.8 degree
Voltage: 3.6V
Current: 2.0 A/phase
Resistance: 1.8Ohm/phase
Inductance: 2.5mH/phase
Holding torque: 12.6Kg-cm 132oz-in , with unipolar (For Bipolar connecting, the holding torque is 185oz-in)
Rotor inertia: 300 g-cm2
Detent torque: 0.4 kg-cm
Number of wire leads: 6
Weight: 0.7KG
Length: 56mm !
does it hold Nema23 ?
Thank you in advance!!!
I built a circuit board am I'm quite sure its exactly the same, I've tested it and it seems to be working fine.
My question is, when I load up Kcam, and switch on the single step mode and bring up the parallel port I/O display window (the window showing the high or low state of the pins) to test the board, It shows that the step bit is always on high state. when I click on a direction it briefly switches to low state then goes back to high state and remains there. Even if i invert the bit it remains the same.
Should it not pulse i.e. go to high state briefly when a button is clicked and then switch off again?? has anyone experienced this problem or is this the correct way to drive the motors.
I'm not sure what the specs of my motors are yet and thus cannot test if they work, but the output pins on the board do switch in the correct order and thus believe that the reason for my motor not responding is because of this.
Any help would be greatly appreciated!
below specification of motor
05 hp
240VDC
1500rpm
pmdc
we are making the pm dc steeper motor system with out vfd.
kindly suggest.
Regards
Mahesh Ganpate
altempowerltd
india
I am asking about computer safety ?.
It will not burn cpu or ram or any part of my computer,by residual current from motor?
t hank you