Dear all.
Firts at all, excuseme for my bad english.
I has bought the big easy driver v1.2.
I need to position a stepper motor with big easy driver and i find this problem:
I send to motor 3200 pulses in clockwise and next other 3200 pulses in counter clockwise.
I use arduino uno.
But the motor don´t position in the same place every time that i move it. There is an error of positioning and i don´t know how find the solution.
I read the big easy driver´s manual.
Motor data
2 phases, 1,8º step, 8 wires, hibrid stepper motor
1,3 Nm; 1,5A; 3,6 ohms; 5,4volts; 10mH.
Can you help me?
thank you so much.
But the motor don´t position in the same place every time that i move it. There is an error of positioning
This means you are skipping some pulses, this can happen if you are running the motor too fast.
Thanks very much, Grumpy_mike.
It´s possible what you say, because I need high speed and i am sending pulse width 100 microseconds.
I read that big easy support pulse width 1 microsecond, but it doesn´t work in my case.
What can i do for running motor faster?
Do you have same idea?
Thank you very much.
It is not the pulse width but the time between pulses that is important.
If you need to run fast without skipping then you need to ramp up the speed at the start and ramp it down when it approaches the end.
You don't say what is the voltage of the supply to the motor. Generally you need a high voltage to get fast movement.
...R
Thank you very much for your help.
I´m going to study what you say for put it into practice.
Thank you for give me light.
Hello, Robin2.
Thank you very much for your help.
The voltage of the supply for the motor is 12 volts.
If i supply with 24 volts can i get running the motor faster?
Thank you very much.
Yes you can get it going at a higher speed with a higher voltage but you have to have the correct sort of driver, one known as a chopping regulator.
What are you using?
The OP says he is using the Big Easy Driver, which is a chopper-style driver.
@Jose: To what value have you set the winding current limit? Big Easy Driver stepper motor driver
Yes I missed that thanks.
It says:-
It can take a maximum motor drive voltage of around 35V,
So upping the voltage as well as the current can make the motor run faster without missing steps. However ramping up ( and down ) the speed is still the best way to get the maximum speed.
The AccelStepper library does acceleration sequencing, which is essential for high
performance stepping (however I think it has quite a low maximum step rate).
If you try to instantly accelerate to a high speed the motor it won't manage it, and
this will lead to mis-stepping and position errors. Its simple physics (T = I dw/dt)!
Than you Grumpy_Mike.
The big easy driver use the A4983 (DMOS microstepping motor driver with translator).
I copy from 4983 datashhets:
" The A4983 includes a fixed off-time current
regulator which has the ability to operate in Slow or Mixed
decay modes.
The translator is the key to the easy implementation of the
A4983. Simply inputting one pulse on the STEP input drives
the motor one microstep. There are no phase sequence tables,
high frequency control lines, or complex interfaces to program.
The A4983 interface is an ideal fit for applications where a
complex microprocessor is unavailable or is overburdened.
The chopping control in the A4983 automatically selects the
current decay mode (Slow or Mixed). When a signal occurs at
the STEP input pin, the A4983 determines if that step results
in a higher or lower current in each of the motor phases. If
the change is to a higher current, then the decay mode is set
to Slow decay. If the change is to a lower current, then the
current decay is set to Mixed (set initially to a fast decay for
a period amounting to 31.25% of the fixed off-time, then to a
slow decay for the remainder of the off-time). This current decay
control scheme results in reduced audible motor noise, increased
step accuracy, and reduced power dissipation. "
Thank you.