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*****You can see more of my projects and updates to my current projects on my website: Colvins.ca*****
***For Support on this Project, Please use the forum on my website. Just go to http://colvins.ca and click the forum link on the side bar.***
I am 14 I have always wanted to build a cnc machine but because inexpensive parts are hard to find in Canada I have had trouble trying to build a decent cnc controller. The purpose if this Instructable is to show that anyone can build a cnc controller using an old scanner. The scanner I used was an old OpticPro scanner. I had previously extracted the stepper motor and experimented with it but not considered it for a cnc controller. All of the controllers on the Internet had a large number of expensive transistors or were ridiculously complex. I finally stumbled across this controller and realized I could build it. By reusing the parts from the old scanner and making the case from recycled cardboard, I am cutting back on my impact on the planet. Also, because this controller is so simple, it only needs one power suply, so, it only needs 1 12 volt (for both the logic and the motors), instead of 1 5volt (for the logic) and 1 12 volt (for the motors). This saves energy, especially when you run it for a long period of time.
If you don't already know what a cnc machine is, it is a machine that uses special motors called stepper motors to moce an object a percise distance. The difference between a stepper motor and a regular DC motor, is that stepper motors "Step", not spin. if you don't understand, refer to this artical. There are two types of stepper motors. There is Bipolar, and Unipolar. Bipolar motors have 4 wires. Unipolar motors can have 5, 6 and 8 wires. The difference between these two types of motors is that unipolar motors have 4 coil inside that, when energized in a certain order, allow it to step forward and backwards. This makes them easy to control and is why we are going to use them in this instructable. Bipolar motors only have two coils that can be energized in forward, or reverse. To drive a bipolar motor you need two H-bridges. Because of this, bipolar motors motor controllers are much more complex.
***For Support on this Project, Please use the forum on my website. Just go to http://colvins.ca and click the forum link on the side bar.***
I am 14 I have always wanted to build a cnc machine but because inexpensive parts are hard to find in Canada I have had trouble trying to build a decent cnc controller. The purpose if this Instructable is to show that anyone can build a cnc controller using an old scanner. The scanner I used was an old OpticPro scanner. I had previously extracted the stepper motor and experimented with it but not considered it for a cnc controller. All of the controllers on the Internet had a large number of expensive transistors or were ridiculously complex. I finally stumbled across this controller and realized I could build it. By reusing the parts from the old scanner and making the case from recycled cardboard, I am cutting back on my impact on the planet. Also, because this controller is so simple, it only needs one power suply, so, it only needs 1 12 volt (for both the logic and the motors), instead of 1 5volt (for the logic) and 1 12 volt (for the motors). This saves energy, especially when you run it for a long period of time.
If you don't already know what a cnc machine is, it is a machine that uses special motors called stepper motors to moce an object a percise distance. The difference between a stepper motor and a regular DC motor, is that stepper motors "Step", not spin. if you don't understand, refer to this artical. There are two types of stepper motors. There is Bipolar, and Unipolar. Bipolar motors have 4 wires. Unipolar motors can have 5, 6 and 8 wires. The difference between these two types of motors is that unipolar motors have 4 coil inside that, when energized in a certain order, allow it to step forward and backwards. This makes them easy to control and is why we are going to use them in this instructable. Bipolar motors only have two coils that can be energized in forward, or reverse. To drive a bipolar motor you need two H-bridges. Because of this, bipolar motors motor controllers are much more complex.
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Signing UpStep 1Required Parts
The parts that are required for this project are:
In the scanner:
-1 stepper motor
-1 uln2003 chip
-2 steel rods
For the enclosure:
-1 cardboard box
The tools:
-Hot glue gun and glue
-Wire cutters/strippers
-Scissors
-Soldering tools
-Paint
For the controller
-1 DB25 port (recycled from previous project)
-some wire
-1 dc barrel jack (recycled from old RC car)
For the test rig
-1 threaded rod
-1 nut to match your threaded rod
-various washers and screws
-scrap wood (recycled from previous building projects)
For the control computer:
-1 old computer (I used an old laptop)
-1 copy of TurboCNC (get it here)
In the scanner:
-1 stepper motor
-1 uln2003 chip
-2 steel rods
For the enclosure:
-1 cardboard box
The tools:
-Hot glue gun and glue
-Wire cutters/strippers
-Scissors
-Soldering tools
-Paint
For the controller
-1 DB25 port (recycled from previous project)
-some wire
-1 dc barrel jack (recycled from old RC car)
For the test rig
-1 threaded rod
-1 nut to match your threaded rod
-various washers and screws
-scrap wood (recycled from previous building projects)
For the control computer:
-1 old computer (I used an old laptop)
-1 copy of TurboCNC (get it here)
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http://www.instructables.com/file/FZ0WAKRGT19NJTB/?size=ORIGINAL
From the page:
http://www.instructables.com/id/Parallel-Port-Break-Out-Board-BOB/step3/Whyd-You-Make-it-This-Way/
Which should have been in my image library but having looked through it a half of a dozen times I'm a bit tired of that now. So those links will have to suffice. Fire the webmaster! Or more fitting in this case, web disaster.
The riser cable is of course the flat gray ribbon cable plugged into the printer cable.
how can i use the CNC version to drive a bipolar motors ? can i do that ?
thank you , great work
http://www.pololu.com/catalog/product/1182
Even my drivers own it handily:
http://www.instructables.com/id/TB6560-Microstepping-Bipolar-Chopper-Stepper-Motor/
Though with built drivers so cheap not worth the trouble building.
To use the cnc machine, you will need to design the item you would like to make in a CAD program such as AutoCAD or Google SketchUp.
Once the item is designed, you must load the item into a CAM program such as MasterCAM or CamBam. In the CAM program, you can create the toolpaths, and then export your model as G-Code, which is what the cnc machine reads.
Finally, you import the G-Code into your CNC program, in this case, TurboCNC. TurboCNC will then control your machine and cut the object out. Hope this helps.
By the same token, I've got boxes of little Nema 23 40 oz steppers that only suck 0.4 amps(400 ma) and by setting my harbor freight minilathe clone(soldby cummins tools) up with the gibs rather loose, I can drive that lathe using those 40 oz stepper motors and this circuit.
And no, I'm not pulling 36" per minute rapid travels or cutting at .015 feed per revolution in hard steel.
Think 5 inches per minute rapid travels as the torque curve of stepper motors starts at it's highest and goes down as the pulses per second increases.
After all, you're not going to built a hurco vertical machining center using this circuit.
This circuit is designed to be built for pocket change and run a little homebrewed cnc mill, router, or lathe for hobby use.
Regular Linux cannot do CNC as the standard kernel is not realtime. This distribution is based on Ubuntu but has the custom software in it to work:
http://www.linuxcnc.org/
You may be interested in a couple articles I put up on this site about my CNC project:
http://www.instructables.com/id/TB6560-Microstepping-Bipolar-Chopper-Stepper-Motor/
http://www.instructables.com/id/Parallel-Port-Break-Out-Board-BOB/
I use EMC2 myself.
If you get it working, let me know, and I will add it to the last step.
To use the cnc machine, you will need to design the item you would like to make in a CAD program such as AutoCAD or Google SketchUp.
Once the item is designed, you must load the item into a CAM program such as MasterCAM or CamBam. In the CAM program, you can create the toolpaths, and then export your model as G-Code, which is what the cnc machine reads.
Finally, you import the G-Code into your CNC program, in this case, TurboCNC. TurboCNC will then control your machine and cut the object out. Hope this helps.
i want to make a 3 axis cnc machine, so how would i wire it for the 3 stepper controllers? and then using the info mentioned in the last step, it would work just fine?
also, how would i use the cnc machine after that, just like a regular one or do i need a specific program?
To use the cnc machine, you will need to design the item you would like to make in a CAD program such as AutoCAD or Google SketchUp.
Once the item is designed, you must load the item into a CAM program such as MasterCAM or CamBam. In the CAM program, you can create the toolpaths, and then export your model as G-Code, which is what the cnc machine reads.
Finally, you import the G-Code into your CNC program, in this case, TurboCNC. TurboCNC will then control your machine and cut the object out. Hope this helps.
Btw, the ULN2803 is compatible with the ULN2003. So it should be in that sense. The only real reason it wont work is because of the software.
-Nadav
http://www.instructables.com/id/TB6560-Microstepping-Bipolar-Chopper-Stepper-Motor/step4/Its-a-runner/
Sorry I could send the PCB format?
thanks