Motors, Drivers & Breakout Board Wiring

[OnezerO]

I'm undertaking my first CNC build and I need help wiring up my electronics. I purchased the motors, drivers, breakout board and power supplies as a kit so I know that they are all compatible. I have just three basic questions for now.

1. The schematic for the wiring shows that the motors can be wired in one of two ways; either (Red & Blue to A+, Yellow & Black to A-, White & Brown to B+, Orange & Green to B-) or (Red to A+, Black to A-, Yellow to Blue, White to B+, Green to B-, Orange to Brown).

What is the difference between the two methods? I suspect the difference is torque and speed but does anyone know which is which?

2. If you notice the wiring schematic only shows a single wire coming from each drivers "Enable + (+5v)" going to the 5v+ on the breakout board.

Do I also need to connect a wire from each drivers "Enable - (ENB)" to the GND on the breakout board?

Can the breakout board be powered in this way from the drivers or does the breakout board need its own 5v power supply?

If I need to provide a seperate 5v power supply to the breakout board does the power connect to the + & - that the drivers are connected to and do I leave the drivers connected to the breakout board as the schematic shows?

3. If you notice each driver lists the options for Pulse/Revolutions which I understand to be the steps. Does anyone have any suggestions on which Pulse setting I should configure the drivers to for best performance from my motors?

I have included pics of the drivers, motors and breakout boards as well as the wiring schematic and information on the drivers & motors. Please let me know if more information is needed in order to help answer my questions.

Thank you.

[doorknob]

1. The schematic for the wiring shows that the motors can be wired in one of two ways; either (Red & Blue to A+, Yellow & Black to A-, White & Brown to B+, Orange & Green to B-) or (Red to A+, Black to A-, Yellow to Blue, White to B+, Green to B-, Orange to Brown).

What is the difference between the two methods? I suspect the difference is torque and speed but does anyone know which is which?

The first wiring method is called "bipolar parallel".

The second wiring method is called "bipolar serial".

The bipolar parallel hookup requires more current but a lower voltage.

The bipolar serial hookup requires less current but a higher voltage.

Or, another way to look at it is that when using the same voltage, bipolar parallel should permit you to get higher speed from the motor (or better torque at a given speed as you increase speed).

One link that discusses this is: UniPolar vs BiPolar wiring schemes for 2-phase Stepper Motors

[doorknob]

2. If you notice the wiring schematic only shows a single wire coming from each drivers "Enable + (+5v)" going to the 5v+ on the breakout board.

Do I also need to connect a wire from each drivers "Enable - (ENB)" to the GND on the breakout board?

Can the breakout board be powered in this way from the drivers or does the breakout board need its own 5v power supply?

If I need to provide a seperate 5v power supply to the breakout board does the power connect to the + & - that the drivers are connected to and do I leave the drivers connected to the breakout board as the schematic shows?

Even though the schematic does not show a wire from the ENAB- terminal to GND on the breakout board (and the driver manual says "usually left unconnected"), my interpretation is that you should connect a wire from each driver's ENAB- terminal to that GND (if you want the drivers to be always enabled).

An alternative interpretation would be that if you want to control the driver's Enable state directly from Mach3 or EMC2 or similar software, then you would need to connect a wire from each axis' enable pin at the breakout board output to the corresponding ENAB- pin of each driver (and you would need to configure the proper enable pins in the "ports and pins" screen of Mach3, or the equivalent screen of EMC2, making sure that they are set up as active low).

That interpretation is bolstered by Fig. 1 of the driver manual. Based on that figure, my interpretation is that the breakout board is not being powered from the connection between the +5V terminal on that board and the ENAB+ terminals on each driver (that connection also goes to the PULS+ and DIR+ terminals on each driver).

Rather, the +5V connection is used to apply power from the breakout board to the input LEDs in the optoisolators within each driver. Those LEDs are turned on when the corresponding - signal (PULS-, DIR-, ENAB-) is at a low level, or turned off when the corresponding signal is at a high level. In that fashion, the signals get passed through the optoisolators without being electrically connected to the motor power supply.

The breakout board is not well documented, but my interpretation is that it must receive power through the terminal marked VDD. It is not clear to me whether the breakout board has an onboard voltage regulator (in which case VDD would want to be set to a voltage higher than +5V) or whether that terminal is simply connected directly to the +5V terminal.

[doorknob]

3. If you notice each driver lists the options for Pulse/Revolutions which I understand to be the steps. Does anyone have any suggestions on which Pulse setting I should configure the drivers to for best performance from my motors?

Your stepper motors are designed for 200 steps per revolution.

The drivers are designed to do microstepping. The pulse/revolution settings start at 400 (which would seem to be equivalent to "half stepping") and go up from there.

Generally, as you increase the pulse/revolution setting, the motion will become smoother as the microsteps become smaller and smaller fractions of the motor's physical step size, however you can reach a point of diminishing returns (and you do not necessarily get any benefit of increased positional accuracy with larger and larger pulse/revolution settings). If you choose too high a pulse/revolution setting, then your computer will have a hard time outputting steps fast enough to give you an adequate speed (in inches per minute) for your machine's axes. With the motors hooked up to your machine, you may find a "sweet spot" to set it at. I can't give you a specific recommendation for your motors and your machine's mechanical specs, but maybe someone else will chime in with their own experience.

[OnezerO]

The breakout board is not well documented, but my interpretation is that it must receive power through the terminal marked VDD. It is not clear to me whether the breakout board has an onboard voltage regulator (in which case VDD would want to be set to a voltage higher than +5V) or whether that terminal is simply connected directly to the +5V terminal.

Doorknob, thank you so much for the detailed and informative responses. I have attached the documentation for the breakout board to this post. Hopefully this will provide some information to help answer my question about how to power this breakout board. I wanted to attach this with my first post but I maxed out my attachment limit.

This breakout board is pretty basic but it was free and came with the kit. I have recently purchased another more sophisticated breakout board which has inputs for manual control but I have not had a chance to mess with it.

Right now I am anxious to get the wiring and power setup correctly to test my motors with Mach 3.

Again, thank you very much and let me know if there is any additional information I can provide.

[doorknob]

The English translation in the breakout board manual is pretty rough.

My take is that the breakout board has its own onboard optoisolators, which duplicate the function of the optoisolators within the drivers (at least for the PULS, DIR and ENAB signals). You don't really need that extra isolation (at least, for those signals), and depending on the quality of those optoisolators, you may find that they might even degrade the quality of the signals that are passed through to the drivers.

The breakout board gives you the option of wiring those optoisolators using two separate +5v power supplies to truly give you electrical isolation, or else you can wire it with a single power supply for convenience and give up on the additional electrical isolation.

If you did want to use the onboard optoisolators for electrical isolation, then you would need to use two separate +5V power supplies (one for the input side of the breakout board's optoisolators and the other for the output side of the breakout board's optoisolators). That is the configuration that the manual refers to as the "double power supply" option. To hook up the board for two separate power supplies, my best guess is that you would have to remove both jumpers JN1 and JN2, and then one power supply (I think that it's the board's input power supply) would be hooked up to terminals +5V and GND, while the output power supply would be hooked up to terminals "isolating source (+)" and "isolating source (GND)", and connect from "isolating source (+)" to the driver terminals that need +5v. (I don't understand the manual's statement: "J4 is the isolating source(GND) and Isolating source(+)" because I'm not sure where J4 is or what it is supposed to do - maybe J4 is just a header pin that may be used to tap off the isolated side's +5v power for use with some other circuitry.)

I really doubt that you want to hook it up that way.

Rather, if you leave JN1 and JN2 in place, then you only need one +5v power supply, and you can connect it to either of the +5v and GND terminals on the breakout board (because both are connected together through the jumpers). That hookup is referred to by the manual as "the case of the single power". Since the two +5v terminals are jumpered together, you can connect the +5v wire to the driver terminals from either of those breakout board +5v terminals.

I hope that is somewhat clear.

[OnezerO]

Thanks again Doorknob, you have been a big help.

I will try and find a 5V power supply lying around the house and wire it up to the breakout board. Do you have any idea how many milliamps I should be using?

Before I even look around for a power supply I am going to check out the manual for my new breakout board I just received. I think it can receive its 5V power via a USB cable from the computer.

[doorknob]

If I counted correctly, there are 17 optoisolators on the board. Each of your drivers also has 3 optoisolators, for a grand total of 26 optoisolators that you need to power. The chances are good that not all of them are going to be "on" simultaneously, but it doesn't hurt to assume that you have to power all of them at once.

If you could read a part number on one of them, you could look for a spec sheet that would give you the typical current draw. Or you could just guess at it. If each opto needs 10 mA, then that would add up to 260 mA total. If you wanted to be conservative and figure that each one needs 20 mA, then you're up to 520 mA.

You can probably easily come up with a wall wart that will give you anywhere from 500 mA to 1 amp.

[OnezerO]

I failed to ask this question in my original post.

If you notice from the pic of the motors I am using the motors are rated at 2.0 amps. I will be using 5 motors in my CNC and each power supply is capable of powering three drivers at a time with a total of 7.5 or 8 amps.

I am assuming that I should set up each driver to provide 2 amps to the motor. Is this a correct assumption?

[doorknob]

First, let me revisit an earlier statement that I made. As for the sizing of the 5v power supply to the breakout board, I made the assumption that you had 3 axes, but from the documentation that you provided (and your most recent post), you actually have 5 axes. So that is two more drivers, meaning an additional 6 optoisolators. It's not a lot of extra current, and I think that you will still be fine if you get a 5v power supply rated for something like 500 mA or 1A. But I wanted to clarify the basis for my calculations.

As for what current to set the drivers for, it is a bit hard to say, because the motor ratings are ambiguous at best. The motor spec sheet gives a current rating of 2A. Is that for a single winding, wired for bipolar serial, or does it mean something else? Maybe you can clarify that with the vendor (and maybe you can get help from an engineer who speaks some form of Chinese so that you can get an unambiguous answer). The motor spec sheets that I have seen from Keling typically have more complete info. Maybe they offer a motor with similar specs. In fact, maybe they also offer a driver with similar specs. (I believe that Keling sources their motors and drivers from China, but I don't think that their motors come from Longs Motor Co.)

I suppose that you could try setting the driver to 2A and see if you have adequate torque, and if not, consider increasing it. As I mentioned earlier, wiring the motors in bipolar parallel should draw more current than wiring them in bipolar serial.

Perhaps someone who has the same motors and drivers can share their actual experience.

[OnezerO]

Thank you so much for all the information you provided to me Doorknob. I believe that I have enough to go on for now.

I plan on using the new breakout board from now on which I hope has better documentation. I suppose I will setup the drivers starting at 2 amps and work up from there if I need to.

[Robinnn]

Hello.
I just bought this board.
Information from this theme is very helpful.
But I have some questions.
Breakout Board have 12 outputs, but unknown what maximum DC and amps of itch.
It is unknown what devices it is possible to connect to outputs (what DC and amps).
It is possible to connect spindle with Inverter to breakout board and than changing frequency?
Can I connect to outputs direct phase control Relay,Solid State Relay, Solenoid coil etc?
It is necessary to connect GND and (+) from " isolating power supply" (witch connecting to drivers) to "isolating source (+)" and "isolating source (GND)" of BOB to use the onboard optoisolators?

I saw this board that looks very similar

Sorry for my English .