How Can I make steps smoother

Hi guys!

I'm making a star tracking mount for my camera.

There was some products I can already buy and use but buying isn't cheap and definitely not fun

I bought a arduino nano
Nema 17 1,7A 200step motor
DRV8825 driver.

I use this very simple code;

void setup() {
pinMode(8, OUTPUT);
pinMode(9, OUTPUT);
digitalWrite(8, LOW);
digitalWrite(9, LOW);
}

void loop() {
digitalWrite(9, HIGH);
delay(1000);
digitalWrite(9, LOW);
delay(1);
}

Every second = 1 second.
I use some other gear part to make it slower but stepper motor too powerfull.
Every step like hitting with hammer.
To much vibration = blurry photo

Is it possible to make it smoother

Thanks for ideas already.
Cheers!

Using the DRV8825 driver you can set the microsteping up to X32. That will make the motion much smoother. Have you tried that? Refer to this Pololu page for how to set the microsteps. You will need to adjust your delay to get the speed that you want.

Some stepper links:
Simple test code
Stepper basics

Yes I heard about microstepping stuff but I just bought arduino and don't know how.
On Pololu web site says set HIGH/HIGH/HIGH but doesn't show how to do it.

Is it on board? or software?
both way I have to ask how.

I'm looking on youtube videos but couldnt find any instruction

set the physical pin on the DRV8825 module to +5V to make it high.

For 5V logic +5V = HIGH, 0V = LOW.

I guess i did it

Made some modification on code

void setup() {
pinMode(8, OUTPUT);
pinMode(9, OUTPUT);
pinMode(2, OUTPUT);
pinMode(3, OUTPUT);
pinMode(4, OUTPUT);
digitalWrite(8, LOW);
digitalWrite(9, LOW);
digitalWrite(2, HIGH);
digitalWrite(3, HIGH);
digitalWrite(4, HIGH);
}

void loop() {
digitalWrite(9, HIGH);
delay(10);
digitalWrite(9, LOW);
delay(1);
}

also connected MO M1 M2 to D2 D3 D4

I guess this method making driver hotter.

There was a small cooler on driver but still hard to touch after 10-15min work

It is normal for a stepper motor and a stepper motor driver to be hot - uncomfortable to touch.

Have you set the current limit on your DRV8825 to 1.7A to match your motor?

If, as you suggest, the motor has more torque than your project needs you may find that it works equally well with a lower current setting and that would allow everything to run cooler.

...R
Stepper Motor Basics
Simple Stepper Code

In normal full step mode yes driver geting hot.
But in 1/32 microstepping mod even more hotter.

Yes this motor is very powerfull. I'm looking for smaller models but they don't have high resolution like this.
I need very slow speed.

I found a small 200step motor in China.
With microstepping I think that will be very good for me.

Also I found TMC2100 driver. According to peoples; it's very very smooth I think. That will be important.

sebatiantr:
Yes this motor is very powerfull. I'm looking for smaller models but they don't have high resolution like this.
I need very slow speed.

Have you tried reducing the current like I suggested?

If you need low speed the best solution is step-down gearing - perhaps with a toothed belt drive because they don't suffer from backlash.

Also I found TMC2100 driver. According to peoples; it's very very smooth I think. That will be important.

I don't see how it can be smoother unless it has a finer level of microstepping.

...R

Robin2:
Have you tried reducing the current like I suggested?

If you need low speed the best solution is step-down gearing - perhaps with a toothed belt drive because they don't suffer from backlash.

I don't see how it can be smoother unless it has a finer level of microstepping.

...R

Yes I made the current setting early but didn't make any change now.

I never use TMC2100 or any other driver or Arduino before.
This is my first experience.

Acording to this video TMC2100 very smooth and silent.

TMC2100 can go 1/256 microsteping.

People says when the DRV8825 getting hot it may skip steps.
I even feel some oddness about pulses. Sometime pulses are not clear and sharp.
I like to try TMC2100 and see how its going.

Another topics.

I have Nema 17 1.7A 7,4V 200steps stepper motor.
On spec and theory it's says every step 1.8 degree.
Is it reliable? or is it depend on power source like AC/DC motors.

sebatiantr:
TMC2100 can go 1/256 microsteping.

That will be smoother

People says when the DRV8825 getting hot it may skip steps.
I even feel some oddness about pulses. Sometime pulses are not clear and sharp.

it is easy to write some code to test for missed steps. I suspect the unevenness is because a micro-step that lands on a full step position will be more precise. Microsteps (with all drivers) are achieved by balancing the pull of the magnets between two full-step positions.

I have Nema 17 1.7A 7,4V 200steps stepper motor.
On spec and theory it's says every step 1.8 degree.
Is it reliable? or is it depend on power source like AC/DC motors.

It will be reliable - it is physically built into the motor.

...R

Use a geared motor. Use a belt drive to damp the vibrations. Give the belt pulleys a 4:1 ratio to increase the overall gear ratio.

Don't worry about the driver or motor getting hot. Unless you have a limited battery capacity and need to save power.

Hello guys.

Yes MorganS I will use at least 2 or 4 gear to avoid vibration and making much more slower rotation.

Now.
I bought a TMC2100 driver.
It's awesome.
I guess this is Chinese copy but still awesome.

With DRV8825 I can feel the pulse unstableness (maybe not right word)

With TMC2100 I have a heat problem again but not the driver. Motor getting really hot this time.

I try with Nema 14 7.4V Pololu stepper motor.
First vref was 0.7V an motor was burning after 1-2 min later. Driver was cool without any heatsink

Then I reduce vref to 0.3V motor was hot but ehhh... Also driver a little hot without any heatsink

I guess we calculate the vref x 2 = current limit.
On Pololu web site says Nema 14 "Current rating: 280 mA per coil" Should I set 0.15V or 0.28 for both coil?

Also another thing bugging me.
Right now I'm at home and using a cheezy 12V 2.5A power supply for external power for motor.
But in my mind I like to use this battery "Sony NP FW50" 7,4V 2000mAh. It's also fit my camera so I can use it both way and easy to charge in my bag with USB powerbank.
But this 7.4V will change my vref setting right?

sebatiantr:
I guess we calculate the vref x 2 = current limit.
On Pololu web site says Nema 14 "Current rating: 280 mA per coil" Should I set 0.15V or 0.28 for both coil?

There are two vital things missing ...

A link to the datasheet for the stepper motor.
A link to the datasheet for the motor driver.

...R

Motor was easy;

Like I said TMC2100 probably a made in China copy (white board).
Last night I couldn't find the proper paper but looking it now.

Robin2:
That will be smoother

it is easy to write some code to test for missed steps. I suspect the unevenness is because a micro-step that lands on a full step position will be more precise.

What I think you are saying is that there is position and torque ripple with microstepping, but its the
best you can do and inherent to the motor itself.