Increase current for Motor Shield

Hi all,

Motor Spec :-
https://www.lazada.com.my/-i11946315-s14673488.html?spm=a2o4k.order_details.list_image.1.3f9149fbjgCQTA&urlFlag=true&mp=1

Adafruit Motor Shield V1 Speck :-

I'm trying to do a XY table where i have to run 2 Stepper motor but the shield could not provide enough current for both the stepper motor.

Is there any solution to increase the current? I have to use the shield because time is limited and I'm in a place where latest component such as Shield V2 is not available and mostly have it can only be obtained through online websites.

Is it possible to stack two Motor Shield or solder another two L293D on the bottom of the shield?
The place here also sell L298N, can I like use two of L298N for each of my stepper motor?

Please help as this is my first Arduino Project

That shield is really not suitable for driving that type of motor. It's like putting petrol (gas) in a diesel engine. It will run for a while but not very well and it's going to get damaged.

Look for anything with an A4988 or DRV8825 chip in it. Those two chips are both very good at driving stepper motors of that size.

While you're waiting for the stepper drivers to arrive on the back of a camel (and a spare motor to replace the one you're going to burn up) can you increase the voltage of your power supply? That will increase the current.

I had a similar problem with the adafruit motorshield, their bus speed is too low and can't run 2 stepper fast at all. I would recommend the A4988 as stated above. I realize you said you are stuck with the shield, but frankly I learned the hard way that those shield really are not that useful. Are you looking for higher speed (rpms)?

Hi,
Stepper specs

Specifications

  • Environment Temperature: -20~50��.
  • RH: 90%MAX
  • Mounting Position: Axis horizontal or vertical installation
  • Direct-current winding resistance (25��): 2.3Ω±10%
  • Wnding inductance: 3mH±20%
  • Cogging torque: 12mN.m REF.
    - Holding torque: ≥300mN.mᆪᄄI=1.5Aᆪᄅ
  • Max. no-load starting frequency: ≥1500pps
  • Max. no-load running Frequency: ≥8000pps
  • Temperature rise: <80K
  • Step Angle Accuracy: 1.8°± 5%
  • Rotary inertia: 38g.cm2
  • Motor Weight: 0.23Kg/PC REF.
  • Insulation resistance: Cold insulation resistance should be more than 100mΩ (between the Motor stator core and Terminal)
  • Dielectric strength: The space between the Motor stator core and Terminal should be able to withstand AC600V/1s without breaking down.
  • Leakage current is less than 1mA.
  • Size (L * W * H): ca. 42 * 42 * 34mm / 1.65 * 1.65 * 1.34 inch

You will need a stepper controller that has a current limit facility.
The Adafruit unit does not have the current rating or the current limiting facilities.
Tom… :slight_smile:

Its a low impedance stepper motor, you cannot drive those with a DC motor shield.

You require a current-controlling stepper driver like a DRV8825

MorganS:
That shield is really not suitable for driving that type of motor. It's like putting petrol (gas) in a diesel engine. It will run for a while but not very well and it's going to get damaged.

Look for anything with an A4988 or DRV8825 chip in it. Those two chips are both very good at driving stepper motors of that size.

While you're waiting for the stepper drivers to arrive on the back of a camel (and a spare motor to replace the one you're going to burn up) can you increase the voltage of your power supply? That will increase the current.

Really appreciate this useful information thanks mate =)

ScoobyDoo:
I had a similar problem with the adafruit motorshield, their bus speed is too low and can't run 2 stepper fast at all. I would recommend the A4988 as stated above. I realize you said you are stuck with the shield, but frankly I learned the hard way that those shield really are not that useful. Are you looking for higher speed (rpms)?

Yeap i'm trying for higher speed as the motor is not behaving as how it suppose to be. I'm totally getting over this shield as it is not useful at all for me

TomGeorge:
Hi,
Stepper specs

You will need a stepper controller that has a current limit facility.
The Adafruit unit does not have the current rating or the current limiting facilities.
Tom... :slight_smile:

Thank you so much for the information as i'm really new to this motor thingy

MarkT:
Its a low impedance stepper motor, you cannot drive those with a DC motor shield.

You require a current-controlling stepper driver like a DRV8825

Thanks for the info =)

As for the power supply, how much should i be getting? i know the formula is V=IR but what is the value of my R ?

The proper stepper controllers do not act as a resistive load. They are more like switchmode power supplies. So you are on the right track by calculating it as power instead of current.

The datasheet specs highlighted by Tom will give you want you need. The DC resistance of the stepper coil is the useful number, along with the max current. Multiply by 2 as there's 2 coils in the stepper but they are never both on at once so multiply by √2 instead (about 1.4).

Then your 12V supply needs to give that amount of power to the stepper driver, plus a little more.

MorganS:
The proper stepper controllers do not act as a resistive load. They are more like switchmode power supplies. So you are on the right track by calculating it as power instead of current.

The datasheet specs highlighted by Tom will give you want you need. The DC resistance of the stepper coil is the useful number, along with the max current. Multiply by 2 as there's 2 coils in the stepper but they are never both on at once so multiply by √2 instead (about 1.4).

Then your 12V supply needs to give that amount of power to the stepper driver, plus a little more.

So the calculation should be, 1.5 A (max current) x 2.3 ohm x √2 = 4.879 V

I should get a power supply that can supply 6V? Or I can get a 12V power supply then step it down to 6V?