# Stepper Motor Driver VS stepper motor controller



## robotdigg (Apr 27, 2010)

Stepper Motor Driver VS stepper motor controller

What is the difference between a stepper motor driver and a stepper motor controller? Let’s find it out.
A stepper motor (or step motor) is a brushless, synchronous electric motor that can divide a full rotation into a large number of steps.
Stepper Motor Driver is a very useful unit which can help the stepper motor to replace the servo motor in some conditions and save you money. A stepper motor driver with microstepping can smooth your step motor and give you wanted torque. Jump in here, a bipolar stepper motor driver can drive 4 lead wires bipolar stepper motor, as well 6 lead wires unipolar stepper motor and 8 lead wires step motor. Stepper motor driver is an open loop system without feedback. 
After known the stepper motor driver so what’s a stepper motor controller? Let’s take it simple way, for sample, UIM240 parallel port stepper motor driver, UIM241 serial port stepper motor controller and UIM242 stepper motor controller with CAN protocol, what’s the difference there? Stepper motor controller is a programming system with a microcontroller built-in but not stepper motor driver. To me, stepper motor controller is more intelligent than stepper motor driver.:nhl_checking:


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## Titus A Duxass (Jan 6, 2010)

Hmmm, sounds like another job for the chamfer bit.


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## ctsooner (Jan 16, 2010)

I know that I'm new to woodworking, but what's this in reference to? is this just about motors used on various routers or am I missing something much bigger? I'm not an EE, but I drove the Kitty Hawk for 5 yrs and was the repair officer. I do have some very basic understanding of motors and understand some of what you are posting. Sorry about being a bit green.


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## Cassandra (Mar 15, 2006)

Maybe Tiger is working with a CNC router machine? If so, this thread belongs in the CNC section.

Cassandra


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## allthunbs (Jun 22, 2008)

Hi Tiger:



robotdigg said:


> What is the difference between a stepper motor driver and a stepper motor controller? Let’s find it out.





> A stepper motor (or step motor) is a brushless, synchronous electric motor that can divide a full rotation into a large number of steps.





> Stepper Motor Driver is a very useful unit which can help the stepper motor to replace the servo motor in some conditions and save you money.





> A stepper motor driver with microstepping can smooth your step motor and give you wanted torque.





> Jump in here, a bipolar stepper motor driver can drive 4 lead wires bipolar stepper motor, as well 6 lead wires unipolar stepper motor and 8 lead wires step motor.





> Stepper motor driver is an open loop system without feedback.
> After known the stepper motor driver so what’s a stepper motor controller?





> Let’s take it simple way, for sample, UIM240 parallel port stepper motor driver, UIM241 serial port stepper motor controller and UIM242 stepper motor controller with CAN protocol, what’s the difference there? Stepper motor controller is a programming system with a microcontroller built-in but not stepper motor driver. To me, stepper motor controller is more intelligent than stepper motor driver.:nhl_checking:


Ok, I'm going back to the early days of computers here. There are four distinct components between the "brain" of your computer and the "appendage" which is your CNC machine.

Somehow, the brain of your computer has to be told that there is something out there that it needs to work with. This is a piece of software that "connects" the brain of your computer to the next component in the "chain." This software is called the "driver." 

Now, the brain will use the driver to just push instructions in the direction given by the driver and, if told to do so, wait for a response. The next item in the "chain" is the "interface." The interface is merely a separate computer that handles communications between your computer and the CNC "appendage." It's job is to handle all of the specific instructions that each command from the brain entails. This frees up the "brain" for other things.

The interface is talking to the controller. The controller's job is to take the instructions from the interface and tell the stepper motor(s) (depending on the complexity and sophistication of the machine) what to do.

Some interfaces are merely communications and others split up the data stream and select controllers as well as pass instructions. 

The Driver handles the brain and the interface. The interface is usually dead dumb and only responds when spoken to. The controller has a whole life of software of its own. You can do almost anything with the controller. It can be smarter than the brain in your computer. 

Then there's the stepper. He's dummer than the interface by a long shot. The stepper only knows two things, he's "turned on" or "turned off." If you want to know more, you have to put a separate controller on the stepper. This adds "a little bit" of "intelligence" to the stepper. Now, he can say he stepped from 271 degrees to 272. He doesn't know what forward or reverse is. That's the controller's job. 

Up to this point, I've said nothing about the application software. There's the graphics program that draws the pretty pictures and creates the database of each line in your picture. Then there's a coversion program that takes the entries in the database and "converts" them to movement in the CNC appendage.

Oops, the CNC is too far from the computer and it's too dusty near the CNC for the computer so somehow there's got to be some sort of communications method between them because the distance between the interface and the controller is too far for the electrical pulses created by the interface.

Hmmmmmm, well, just pump up the power of the signal so the controller can hear it. Oops, that's too many wires and they keep interfering with each other. Well, we'll use "one" wire and put a radio station at each end of the wire. We'll create a protocol to manage the communications between the two radio stations. Now, the interface can talk to the controller through the radio stations whose activities are managed by a protocol.

Hmmmm, this protocol idea ain't that bad. Let's create a protocol to manage the interface and controller. 

And now starts the real sophistication in CNC. Manufacturers "blend" components and protocols to improve accuracy and speed, and sometimes to achieve both they have to make compromises. Eliminate a point of a compromise and the price goes way up. Eliminate all of the compromises and you've mortgaged your great grand children's lives.

This is accurate only as to concepts and in reality can be drastically different than what is happening. I've used author's license to create a picture. Once you start expanding your knowledge you'll fill in and modify what this tomb describes.


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## Check twice! (Feb 11, 2008)

WOW, maybe simple is best, I always like to keep things simple (it is my simple mind).

For a CNC to work, we require several components. Starting at the conception of an idea.
1. We require a program to draw our project, this can be in 2D or 3D, VCarve, Solid works, Art Cam are a few programs available. Your choice is dependent on project, cost, and what you feel comfortable with.

2. Once you have your project created the program will convert it into G code for you so the interface program such as Mach3 understands what it is wanting it to do.Now both these programs are on the same page with a common language. At this point Mach3 is in charge of the cut. It says OK I have the program ,,, what am I to do with it. Mach3 keeps sending messages but nothing is happening. Mach3 needs a controller between it and the motors. (As Ron says a motor is dumb as a fence post) The motor only understands one thing electric pulses. 

3. Then we have a controller that has the drivers built on the board. (the drivers give the impulse to a particular motor). There are several types of controllers and depending on the number of axis the controller will have drivers for each motor. The most common is a 3 axis system X,Y,Z and if a fourth axis is required it will be called A. 

4. Since Mach3 is in-charge (the controller on it's own is dumb as a post as well) it will not do anything without an order from Mach3 or similar program. When Mach3 sends a message to the controller, (it being a follower it does as it is told) and sends a impulse to a motor and depending on how far and which axis motor Mach3 wants moved in a negative or positive fashion it follows instructions.

It is like an army.
Government-- (VCarve) makes the plan and sends it to the General. 
General-- (Mach3) sends a message to the company commanders. 
Company commanders-- (Controller) sends a message to the right platoon. 
Platoons-- (Motors) follows orders and does as it is told. 

This is far from the whole process but the flow of information works in this fashion. I am not sure if this was what Tiger was getting at but the flow chart can't hurt. 

Have a great day!


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## Hamlin (Dec 25, 2005)

Cassandra said:


> Maybe Tiger is working with a CNC router machine? If so, this thread belongs in the CNC section.
> 
> Cassandra


I have to second this notion.


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## robotdigg (Apr 27, 2010)

Thanks John, you make the answers clear and simple.


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## ISHAMON49 (May 23, 2008)

What about servos?
ish


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## Check twice! (Feb 11, 2008)

Hi ish

Servos verses steppers is a debatable topic. All the information I have read on both types seems like we would be comparing apples and oranges. I believe it is dependent on who makes them as to who says one is better than the other.

Their are 3 types typically used in CNC machines. The first being steppers, the second being servos, the third being intelligent servos. They all basically do the same job but in my opinion for different styles of machines. There are pros and cons for all three.

They are all just as accurate, as I see it (debatable) but your big difference comes in at cost and setups.

Steppers are less expensive (about half the cost of servos) and set up is much easier than servos especially when replacing a motor. Steppers will also miss steps rather than try to push through and break a gear or burn up.

With servos you require encoders and the set up could be almost double the time, and with no gain in accuracy. They do come in much larger sizes than steppers and are ideal for large heavy machines, but have little or no advantage in light machines.

I have used steppers but not servos so my info on servos is limited to what I have read.

Manufactures will try and say theirs are better, and I believe each has it's own strength and weakness. I use steppers because of their cost and ease of set up.

Just my opinion, not a scientific study,


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## ISHAMON49 (May 23, 2008)

Hi Check twice,
I beleive that you are absolutely correct. Application and environment should drive the decision making process as it relates to the steppers vs servos debate; and cost as well.

I have have found, though my years of practical experience (with servos, millimg and turning ISO parts for world class industries), that encoders rank very high when one seeks the weakess link in a servo system. I have also found this to be true relative to large format printers, plotters and simular servo driven devices.

It remains a joy to work with my stepper systems. 

ish


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## Metalhead781 (Jul 27, 2010)

Cassandra said:


> Maybe Tiger is working with a CNC router machine? If so, this thread belongs in the CNC section.
> 
> Cassandra


i thought this was the cnc routing section:jester:


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## Cassandra (Mar 15, 2006)

Hi Randy:

I believe that this thread originally was in a different sub-forum and has been moved to the CNC sub-forum. As a consequence, my comment became irrelevant.

Cassandra


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## Check twice! (Feb 11, 2008)

Now Cassandra, would you have got Randy to reply with a funny, if your comment was irrelevant? 

You were right at the time, it was a new post. 

Have a great day gentlemen.


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## Cassandra (Mar 15, 2006)

Check twice! said:


> Have a great day gentlemen.


What about us ladies? :sarcastic:


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## ISHAMON49 (May 23, 2008)

Greeting to all,

I was trying to generate a little humor with my "What about servos question?". I had a general feeling that the debate was rooted in motion control. To that end, all were clearly accurate and informative. I'm feeling a little guilty for taking the servo detour.

Please forgive me.

Thank to all
ish


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## Check twice! (Feb 11, 2008)

Cassandra said:


> What about us ladies? :sarcastic:


OK, Ladies and gentlemen, as I remove foot from mouth and slowly insert other. 

We all know what the word "ass/u/me", sorry. I should never assume and look before I speak. My bad. :bad:

Have a great day,,,,, people.


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## Check twice! (Feb 11, 2008)

ISHAMON49 said:


> Greeting to all,
> 
> I was trying to generate a little humor with my "What about servos question?". I had a general feeling that the debate was rooted in motion control. To that end, all were clearly accurate and informative. I'm feeling a little guilty for taking the servo detour.
> 
> ...


Be happy, no wrong, sometimes a detour has some great scenery. I have enjoyed the scenery and the company. 

Enjoy the day and keep "creating" and "posting", I enjoy your work and our chats. 

Chat again.


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## Dorisz11 (Aug 31, 2010)

robotdigg said:


> Stepper Motor Driver VS stepper motor controller
> 
> What is the difference between a stepper motor driver and a stepper motor controller? Let’s find it out.
> A stepper motor (or step motor) is a brushless, synchronous electric motor that can divide a full rotation into a large number of steps.
> ...


Check out the video I posted!


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## jeremy budgen (Oct 9, 2010)

John 

When i first built a cnc machine i used size 42 steppers with gecko drives and deskcnc setup, i found that this setup is a simple way to get going as all seem to connect very easily with each other.

My machine was a 9` x 6` flat bed machine with gearboxes attachen to the x and y axis for good torque, when the machine was jogging in the x axis, i could not hold it back that how strong it was.

I have since disassembled the machine as i have a factory built machine now, i am current looking into building another cnc that has falt bed vacuum and also a lathe attached to one end.


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## Check twice! (Feb 11, 2008)

jeremy budgen said:


> John
> 
> When i first built a cnc machine i used size 42 steppers with gecko drives and deskcnc setup, i found that this setup is a simple way to get going as all seem to connect very easily with each other.
> 
> ...


Hi Jeremy

Did you consider putting a fourth axis into your new build. Scott and I are planning to leave the space to add the fourth axis in our new build at a later date. This may give you the versatility of the lathe and CNC router. Just a thought!

It is great fun building and overcoming the many pitfalls that seem to pop up during a build. Good luck with your new build and hope you post it (with photos) I always enjoy the many ways people overcome the pitfalls and their final result. 

Hope we chat again.


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## jeremy budgen (Oct 9, 2010)

John

I forgot to mention that yes i will have an indexer stepper mounted to one side of the lathe and a normal motor attached to the other, so when i need the the normal motor i just engage the pulley belt to the variable pulley on the lathe and when i need the indexer i engage the toothed belt on a special chuck that has a toothed geared pulley attched. Also i am going to have a fixed cutter attached to the bottom of the z axis, the same you get with a normal copy lathe, which will do the initial lathe work..


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## jeremy budgen (Oct 9, 2010)

John

Just remember to have enough travel on the x axis so that the gantry can pass over the end of the routing table..


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## medkellogg (Mar 12, 2012)

*Servo vs Stepper*

Adding a bit more about stepper motors and servo motors or servo mechanisms...

Stepper motors are constructed to divide a single rotation into multiple steps and do not employ any positional feedback. The signal to the stepper tells it to go "x" amount of steps, which equates to a rotational distance, where it stops. As stated above they generally are not able to provide as much torque or power as a servo motor.

Servo mechanisms are designed with a motor, which when turned on by a signal, will begin to rotate. The second part of the servo mechanism is a method of feedback telling the controller how far the motor has moved, and when the required distance is reached it will turn off the motor. A garage door opener is a servo mechanism with feedback telling it when the door has opened or closed.

Obviously there is a bunch more complexity to both stepper motor and servo mechanism systems, but hopefully this will capture the basics.


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## frank133 (Mar 31, 2014)

Great Thread! It helped me with my motor.
I got my motor at Motion Marketplace


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