Help with L298N

[bjwx2]

Can anyone tell me which wires from controller are attached to pins labeled "input", thanxhttps://www.cnczone.com/forums/attac...d=396692&stc=1

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[john-100]

if you can not download the instructions for your L298N board from the supplier

try comparing your board with the L298N dual H bridge data sheet from

https://www.st.com/en/motor-drivers/l298.html


how are you using the L298N?

normally the 4 inputs connect to the outputs of a L297N


L298N PDF data sheet
L298.pdf
see page 8 for connections to L297N

John

[bjwx2]

Thanx for the reply, not much on electronics schematics, trying to run nema 34 motors thru a grbl controller, suppliers data sheet doesn't designate the wiring for the input connections.

[CitizenOfDreams]

Four logic signals, TTL level. What kind of controller are you connecting it to?

Edit: As far as I understand, grbl works with STEP/DIR stepper drivers. L298N is just a dumb H-bridge.

[bjwx2]

Using this controller with L298N H-bridgehttps://www.cnczone.com/forums/attac...d=396708&stc=1

[bjwx2]

OOPS, this controllerhttps://www.cnczone.com/forums/attac...d=396710&stc=1

[john-100]

can you post the part number of the controller & link to the manual ?


looking at the photo
it looks like a version of an Arduino board using an Atmel micro controller

on the red stepper driver boards you can see the location of the step & direction pins


to use the L298N board you need to add the L297N to convert it into a working stepper motor driver

why did you want to use the L298N instead of the A4988 stepper driver

John

[bjwx2]

I guess what I don't understand is why I can't drive the stepper motors directly from the controller. The motors will move, but don't seem to be getting enough power, btw the controller has A4988 drivers. The supplier I bought this from only furnished me this for schematic, thanxhttps://www.cnczone.com/forums/attac...d=396714&stc=1

[john-100]

I have not found your Laser Engraver Controller or its schematic

without the details of the control IC used its hard to say what current you can take from any of the boards outputs
but its going to be limited to around 20ma at most

using 2 pins to drive a A4988 stepper driver for instance to control 35V at up to 2A for the motor
it will simplify the software to control the stepper motors

as the A4988 has an up / down counter controlled by the step & direction inputs
and a translator to generate the correct switching sequence to power the motor coils depending on the microsteps you are using

also the A4988 controls the motor current - see the potentiometer on the module to set the current
( its not the motor supply voltage divided by the coil resistance )



what is the motor part number of the motor your using ?

Nema 34 only gives the size of the end of the motor 86 x 86mm ( the length varies with the torque)

with the part number to look up the data sheet it will indicate the motor current you set the stepper driver to

as the motor supply is limited to the 12V input to the Laser Engraver Controller
the motor inductance needs to be low

look for the data for the A4988 stepper driver module you have to see how to set the microsteps

it has five selectable step modes: full, 1/2 , 1/4 , 1/8 1/16

the motor current is set by the tiny potentiometer on the board

you need to know what the motor needs
and have the setup instructions for the A4988 stepper driver module you have

different manufacturers fit different values of current sense resistors
so the voltage you set the potentiometer to
will varies for the same motor current

John

[hfjbuis]

I guess what I don't understand is why I can't drive the stepper motors directly from the controller. The motors will move, but don't seem to be getting enough power, btw the controller has A4988 drivers. The supplier I bought this from only furnished me this for schematic, thanxhttps://www.cnczone.com/forums/attac...d=396714&stc=1

You can drive steppers (4 lead) using this board. But to run a Nema34 stepper at full power, you probably need more current delivered from the driver. However, if you set the current pot to max, it will not kill your motor. The driver will probably heat up very fast and then shutdown to prevent damage. But the stepper should run for some time at a modest speed, with reasonably power.
If you want more power, you could use the same board connected to external drivers having their own power supply. Than you can run this heavy Nema34 stepper at full power.

A L298 is has a max current of 4 A for both coils. The A4988 driver has the same max current and can drive 4 wire steppers. Changing to L298 has no advantages!

[bjwx2]

Thanks! I appreciate your kind responses!

[bjwx2]

What drivers would you recommend?

[john-100]

what is the part number of the motors ?

you need to find the data sheet for the motors to find out
what current they are designed for and the inductance of the coils

then you can find stepper drivers to match the stepper motors

the square root of the motors inductance in mH x 32
gives you an idea of what is the ideal supply voltage for the stepper drivers


for example
the 23HS8430 stepper motors I have
have an inductance of 3.5mH and has a rated current of 3A

with the 3.5 mH inductance the ideal supply voltage is about 60V
using a Gecko Drive G540 with a maximum of a 50V supply would limit the maximum motor speed

stepper driver boards using the THB6064AH is an alternative to the Gecko G540 but is still limited to 50V

avoid the infamous TB6560 boards


John

[bjwx2]

85BYGH450 C-060
How about tb6600?

[hfjbuis]

85BYGH450 C-060
How about tb660?

Wow, this is an 6A 8 mH stepper capable of delivering 12 Nm.

I don't think you can get the max torque/speed out of this beast unless you spent more money on the driver(s) and power supply then on the total machine. I can not image you need such powerful stepper.

I can run a nema23, 2Nm, 3A , 3.5 mH stepper using a very cheap (6 $) TB6600 driver, 26 Volt power supply and 4 micro steps at 1200 RPM and still have torque. I suggest you try this TB6600 driver with your current power supply and then decide where to go from there.

check this video

[john-100]

having searched for your 85BYGH450 C-060 stepper motors



the 6A current and 8mH inductance limits the choice of stepper drivers you can use to get the most from the motors

if you use the rule of thumb square root of inductance x 32 = supply voltage

the square root of 8 x 32 = stepper driver supply voltage

2.8 x 32 = 90V

using a driver that can not supply 6A will reduce the torque the motor can produce and
a supply voltage of less than 90 V will reduce the maximum speed you can step the motor

the faster you step the motor the higher voltage needed to force the current to build up to 6A
in the time available between steps


John

[bjwx2]

Switched to NEMA 23 steppers and tb6600 drivers, still only getting 5V to motors, apparently I'm missing something here, am attaching photos, perhaps someone can take these photos and
show me how to wire this, understand, I am a novice at this.https://www.cnczone.com/forums/attac...d=397116&stc=1

[hfjbuis]

If the stepper turns, you have connected the A+,A-,B+,B-, Step, Enable and Dir pins the right way.

You have to power the TB6600 driver directly from the 12 Volt power supply. Or if you have, use another power supply.

The power supply (+ or Plus or VCC) goes to the VCC input of the TB6600. Most of the time, this is the centre connector of the round power supply output pin.
The power supply (- or Min or GND) goes the goes to the GND input of the TB6600. Most of the time, this is the outer of the round power supply output pin.

If you have a voltmeter, check the voltage (polarity) before you make the connections to the TB6600 (you must have a voltmeter otherwise you couldn't know the TB6600 was powered by 5 volt supply).

Let us know the results.

[bjwx2]

ooops, I have NOT connected the step, enable and direction wires, furthermore I have no idea where these are on my board, I have the power supply (30V 6.5A) connected properly and have the +5v connected, really appreciate your time and help with us!

[hfjbuis]

On the "old" driver boards, you can see witch pin is the step, dir or enable pin. You have to remove this A4988 board! To get the stepper running (for testing), you only need to connect the step pin.

Give it a try!