Low voltage Stepper Motor driven by Arduino

Other Hardware Motors, Mechanics, Power and CNC
1

Hello People,

i have a problem to understand how to power up a stepper motor. For my project i choose http://tinyurl.com/lae4vac this one.

Manufacturer Part Number: 17HS19-2004S
Step Angle: 1.8°
Step Accuracy: 5%
Holding Torque: 59Ncm(83.6oz.in)
Rated Current/phase 2.0A
Phase Resistance 1.4ohms
Voltage 2.8V
Inductance 3.0mH±20%(1KHz)
Weight 400g

Can i drive this on with a L298n on 12V. I really dont understand the power-supply-problem. If not what would be an alterative to connect this one to an arduino. I have already a motorshild from ladyada with the L293d, but i think it is a bit to "weak".

Thank you

2

2A is past the range that can be comfortably driven with anything cheap, alas.

Your best bet is DRV8825 module, you might get up to 2A without too much
heating (fan cooling advised).

L298 - no chance at all, this is a motor requiring current drive, not voltage drive.

BTW why did you select a low impedance motor? Do you need the speed performance?

3

The Thread stepper motor basics may provide some useful background.

...R

4

Jo,
thank you so far...

The link was great. I figured out that i could use one of those A4988 with heatsink, if i choose a other motor. Is it right that i have to adjust the current to the maximal level of the motor by hand? And how could i do that? Measure the current flowing though the motor? Or can that destroy one of the components, if the current skrew is set to a high level.

If i choose this motor:
Model: 17HS4417
Frame Size: Nema 17
Step Angle: 1.8 degree
Voltage: 3.4V
Currrent: 1.7A/phase
Resistance:2.0 Ohm/phase
Inductance:3.0mH/phase
Holiding Torque: 4000G-cm=40N.cm
Rotor inertia: 54 g.cm2
Detent torque: 0.22 kgcm
Leads Number:4
Weight: 0.24KG
Length: 40mm
Motor shaft:5mm

Is it possible to power the driver with 12V, and it will make a constant current?
I chose the other motor because of the relative high torque, nothing else.

thanks
hendrik

5

The Pololu A4988 web page explains how to set the current limit.

Assuming you have read stepper motor basics I don't understand this question

Is it possible to power the driver with 12V, and it will make a constant current?

...R

6

indeed i read it...
just wanted to make sure, i understood it correctly

7

hotto:
indeed i read it...
just wanted to make sure, i understood it correctly

I still don't understand your question.

A stepper motor cannot run with a constant current - it needs a series of pulses of current. I guess the current will be constant when the motor is stationary.

...R

8

The OP means will the A4988 provide current drive - yes it does, and you can power it
from 24V for better performance (higher max speed).

1.7A is still high, the DRV8825 is still seemingly the best performing single-chip driver,
with the A4988 try using 1A drive only. You will need some cooling (tiny fan perhaps)
to get the best from the A4988.

Hopefully in the future someone will bring out a shield based on the DRV8711
(see http://www.ti.com/tool/BOOST-DRV8711) as that promises to fill the gap between single-chip drivers and
industrial stepper drivers (expensive). The DRV8711 needs 8 external MOSFETs
but can easily then deliver 5A or more without cooling required, from what I've
seen of the specs.

The issue is MOSFET on resistance - the single chip drivers are all limited to on-chip
DMOS MOSFETs, which at best have 200 to 300 milliohms of on-resistance, whereas
discrete external MOSFETs are available down to < 1 milliohm (10 milliohm for
the cheaper devices).

9

What i meant was that the driver limits the current to an adjustable level. Ofcause the current is not stable while stepping.

My idea is to set the 8825 in this http://m.ebay.de/itm/251739070525?nav=WATCHING_ACTIVE board. Apply a heatsink and put a pc- fan in top. Better safe than sorry, or as we germans say: safe is save :wink: