# stepper motor driver ,1.6v ,3.9a

Thread Starter

#### Saeid Alipour

Joined Nov 9, 2018
11
hello everyone, I have 4 1.6 v - 3.9 stepper motor. I want to use them in 3d printer but I can't find a suitable driver for that, most of the drivers are 5 to up amper and volt. can you offer a driver to support my stepper motors or a way to build that? It's better that it can relate with RAMPS .

#### DNA Robotics

Joined Jun 13, 2014
501
I would use something like this.
https://www.mpja.com/Stepmotor-Driver-3A-Max-TB6560/productinfo/31306+MS

Typically with little stepper motors like that, to get any torque, you drive them with a higher voltage but limit the amps.
In your case, I would start with 12 volts because it is common, and start with the minimum amperage. Then slowly increase the amperage until the motor is strong enough to do the job without getting too hot. If it won't do the job without getting too hot, you need a bigger motor.
Just to be safe, put a 20 ohm resistor in series with each winding to start.

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Thread Starter

#### Saeid Alipour

Joined Nov 9, 2018
11
I would use something like this.
https://www.mpja.com/Stepmotor-Driver-3A-Max-TB6560/productinfo/31306+MS

Typically with little stepper motors like that, to get any torque, you drive them with a higher voltage but limit the amps.
In your case, I would start with 12 volts because it is common, and start with the minimum amperage. Then slowly increase the amperage until the motor is strong enough to do the job without getting too hot. If it won't do the job without getting too hot, you need a bigger motor.
Just to be safe, put a 20 ohm resistor in series with each winding to start.
its volt is 1.6 if I use 12 volts won't I have a problem?

#### DNA Robotics

Joined Jun 13, 2014
501
Stepper motors aren't very strong. 1.6 volts X 3.9 amps = 6.24 Watts. About the same as a night light that barely glows in the dark.
Lets wait for more input / opinions.

Thread Starter

#### Saeid Alipour

Joined Nov 9, 2018
11
Stepper motors aren't very strong. 1.6 volts X 3.9 amps = 6.24 Watts. About the same as a night light that barely glows in the dark.
Lets wait for more input / opinions.
thanks.

Thread Starter

#### Saeid Alipour

Joined Nov 9, 2018
11

#### BobTPH

Joined Jun 5, 2013
2,027
Stepper motors are inductive , so the current takes time to build up. The 1.6V 3.9A spec is static. If you apply 1.6V it will take a certain time to reach 3.9A and then it will stay there. But if you need to step faster than that interval, it would never get to 3.9A and you would lose torque. Eventually, it cannot step any faster.

So, to overcome this limitation, you give it a higher voltage, wait for the current to get to some set value less than 3.9A, the cut off the voltage. You then continue to turn the voltage on and off (PWM) to keep the current constant . This is all done by the driver. A driver will have a max current it can deliver and some way of setting the actual current to a lower value. A driver that can deliver up to 5A but can can be set lower is what you need.

Bob

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Thread Starter

#### Saeid Alipour

Joined Nov 9, 2018
11
Stepper motors are inductive , so the current takes time to build up. The 1.6V 3.9A spec is static. If you apply 1.6V it will take a certain time to reach 3.9A and then it will stay there. But if you need to step faster than that interval, it would never get to 3.9A and you would lose torque. Eventually, it cannot step any faster.

So, to overcome this limitation, you give it a higher voltage, wait for the current to get to some set value less than 3.9A, the cut off the voltage. You then continue to turn the voltage on and off (PWM) to keep the current constant . This is all done by the driver. A driver will have a max current it can deliver and some way of setting the actual current to a lower value. A driver that can deliver up to 5A but can can be set lower is what you need.

Bob
thanks, do I understand right? I can give higher voltage, for example 10v, and it causes lower amper and I lose some torque. It's right?

#### BobTPH

Joined Jun 5, 2013
2,027
thanks, do I understand right? I can give higher voltage, for example 10v, and it causes lower amper and I lose some torque. It's right?
No, the toque dpends entirely on the current. You need a higher voltage to keep the current up at high stepping speeds.

Bob

Thread Starter

#### Saeid Alipour

Joined Nov 9, 2018
11
No, the toque dpends entirely on the current. You need a higher voltage to keep the current up at high stepping speeds.

Bob
ok, is the driver TB6600 suitable or can you offer a driver that can relate with RAMPS?

#### MisterBill2

Joined Jan 23, 2018
3,883
Like has been stated already, probably the little stepper motor will not be adequate for much of a 3D printer. AND, using the series resistor we used to use 24 volts to drive the 3 volt steppers. That is how the inductance was over come. But caution advised here, which is that because they are inductive, big time, there is a large spike as the drivers switch off. So any driver must be able to deal with that, meaning that when they say connect a big external capacitor, do it. We destroyed a $175 driver in about 5 steps, neglecting that capacitor.. Thread Starter #### Saeid Alipour Joined Nov 9, 2018 11 Like has been stated already, probably the little stepper motor will not be adequate for much of a 3D printer. AND, using the series resistor we used to use 24 volts to drive the 3 volt steppers. That is how the inductance was over come. But caution advised here, which is that because they are inductive, big time, there is a large spike as the drivers switch off. So any driver must be able to deal with that, meaning that when they say connect a big external capacitor, do it. We destroyed a$175 driver in about 5 steps, neglecting that capacitor..
ok thank u friend .

#### MisterBill2

Joined Jan 23, 2018
3,883
ok thank u friend .
OK, I looked at the picture and it seems that my evaluation was a bit hasty, because that stepper is quite a bit bigger than the ones in printers. So now the questions are about how much speed you are going to want. The reason for the much higher voltages and big resistors is speed. At slower speeds there is not the reason to force a faster rise time on the current, which in turn will make the system more efficient and simpler. The other consideration is the size of the steps the printer will be making versus the steps per revolution for the motor. So the actual determination is not simple. Start with choosing the resolution you want from the printer, and then you will have the distance per step, which relates to the physical coupling between the motor and the print head. Unfortunately I do not see any description of the number of steps per revolution or degrees per step. Similar step motors that I am familiar with turn 1.8 degrees per step, or 200 steps per revolution. If the print head movement was 1 inch per revolution that will give a resolution of 0.005 inches per step, which is reasonable for most hobby applications. .So now you have some things to consider, or perhaps you already did consider them.
Those motors could certainly work, but not as fast as some printers run.

#### MaxHeadRoom

Joined Jul 18, 2013
19,042
The old resistor/volt drop method is rather ancient now, it is currently done using PWM controllers, there are both quite a few suppliers and designs out there for DIY.
Max.

Thread Starter

#### Saeid Alipour

Joined Nov 9, 2018
11
OK, I looked at the picture and it seems that my evaluation was a bit hasty, because that stepper is quite a bit bigger than the ones in printers. So now the questions are about how much speed you are going to want. The reason for the much higher voltages and big resistors is speed. At slower speeds there is not the reason to force a faster rise time on the current, which in turn will make the system more efficient and simpler. The other consideration is the size of the steps the printer will be making versus the steps per revolution for the motor. So the actual determination is not simple. Start with choosing the resolution you want from the printer, and then you will have the distance per step, which relates to the physical coupling between the motor and the print head. Unfortunately I do not see any description of the number of steps per revolution or degrees per step. Similar step motors that I am familiar with turn 1.8 degrees per step, or 200 steps per revolution. If the print head movement was 1 inch per revolution that will give a resolution of 0.005 inches per step, which is reasonable for most hobby applications. .So now you have some things to consider, or perhaps you already did consider them.
Those motors could certainly work, but not as fast as some printers run.
yes, this motor is 1.8 degrees per step too, the speed isn't important for me, It's my first 3d printer, I just want to run it safely and efficiently.

Thread Starter

#### Saeid Alipour

Joined Nov 9, 2018
11
The old resistor/volt drop method is rather ancient now, it is currently done using PWM controllers, there are both quite a few suppliers and designs out there for DIY.
Max.
yes I know, but I must use a drier that can supply 4 amperes and don't harm to that with high voltage.

#### MisterBill2

Joined Jan 23, 2018
3,883
yes I know, but I must use a drier that can supply 4 amperes and don't harm to that with high voltage.
Since it appears that this is a 6-lead stepper motor, intended for unipolar operation, it would be easy to use a lower powered stepper drive IC to control 4 transistors of adequate current and voltage ratings, and quite likely less expensive as well. AND it should also be possible to use the half-step mode, with 0.9 degrees per step. That will double the resolution at the expense of speed.
But still, the connection between the motor and the distance the print head moves per step must be figured out. The mechanical design will be the hard part.

Thread Starter

#### Saeid Alipour

Joined Nov 9, 2018
11
Since it appears that this is a 6-lead stepper motor, intended for unipolar operation, it would be easy to use a lower powered stepper drive IC to control 4 transistors of adequate current and voltage ratings, and quite likely less expensive as well. AND it should also be possible to use the half-step mode, with 0.9 degrees per step. That will double the resolution at the expense of speed.
But still, the connection between the motor and the distance the print head moves per step must be figured out. The mechanical design will be the hard part.
ok , thanks