4

When there is miscommunications between the microcontroller and a chip, assuming the electronics are not damaged, there could be a couple of things that can go wrong. Of course, further diagnosis is required. Typical things that could go wrong are (generally, not just in your particular case): Connections: Is the chip connected to the correct power supply? ...


4

I found that the FFT of the current waveform of the stepper often shows the natural frequency harmonics of the motor+driver system AND that during a stall extra frequency harmonics appear!!! all you need is a fast, bidirectional current to voltage conversion IC and a narrow band pass filter to detect if the extra harmonics are present.


3

You won't ever get 'exactly' 2042.8878 RPM, so going with your measurement accuracy I will assume you mean 2042.8878 +/- 0.0005 RPM. This is approximately an error of 1 part in 4 million. So let's assume you can set up a timer which counts up to around 4 million and resets, and use that for the PWM. Assuming a two pole motor, 2042 RPM is 34 electrical ...


3

From wikipedia http://en.wikipedia.org/wiki/Stepper_motor Because windings are better utilized, they are more powerful than a unipolar motor of the same weight. This is due to the physical space occupied by the windings. A unipolar motor has twice the amount of wire in the same space, but only half used at any point in time, hence is 50% efficient (or ...


3

You need to quantify : "I measured the current through (one of the 4 wires of) my stepper motor, and it's always within a few percent of 0.5 A". A 'few percent' may be all you need to detect a little extra current during stall (if there is extra current as I would also assume but would need to prove), which can be sensed and compared to normal stepping ...


2

I know this thread is old but it's high on Google results and I would like to clarify for anyone who stumbles upon it in the future an answer not yet listed: this chip is not designed to read current accurately below 0.3A and only gives 20% accuracy above that. This is not listed in the board spec sheet but rather the chip spec sheet. If you're running ...


2

I'm using a NEMA23 on my Y axis on my greatly frankensteined MendelMax. The bed was elongated to 350mm along with other upgrades, so I needed the bigger motor. It's running nice and cool at 26 volts on standard Pololu DRV8825 stepper motor controllers. Note however that CNC platforms and 3D printer platforms have only three things in common: X, Y, and Z ...


2

The reason for this is that when attempting to hold a position between positions, you are not only fighting the torque from your load but that generated by the magnets in your stepper more info here


2

As long as the steppers are running relatively slowly, let's say a few hundred steps per second, you should be fine. Your driver uses PWM to control the current through the motor windings. In microstepping mode the driving waveform at the motor terminals looks like a sine and cosine (sines offset by 90 degrees) and the driver modulates the outputs to ...


2

If you want to build something that more or less resembles CNC machine, and use a pen as a tool and draw some pictures, then you will probably be fine (as long as you can do programming and have a lot of patience to do calibration). Why is this not a common solution? Usually you want CNC to be precise and to have enough power to move a tool at reasonable ...


2

CNC controllers, in most cases, control rotary motion and the model of how this rotary motion is tranformed, by the mechanism attached to the motor, to a translational motion is implemented in the controller. You can use any method of transforming rotary motion to a linear motion as long as the model for it is pre-implemented in the CNC controller or you ...


2

Here you go. This will control 2 steppers on an Arduino. #include <Stepper.h> #define STEPS 200 // change this to the number of steps on your motor // create an instance of the stepper class, specifying // the number of steps of the motor and the pins it's attached to Stepper stepperX(STEPS, 2, 3, 4, 5); // Arduino pins attached to the ...


2

How does a controller translate a move x 20 units to moving the stepper x amount of steps and keep dimensional accuracy? If the CAD G-code says move 200 mm in the x direction, how to you translate the G-code to tell the stepper motor that 200 mm? The G-Code interpreter interprets the motion command. It applies some basic transformations on it to make sure ...


2

So you have three different questions here I will answer them separately: Q: How is Mach 3 controlling steppers? Mach 3 normally uses a step and direction interface where it is abusing the parallel port on your PC to output signals. A step and direction port does just what it sounds like, it has one pin where every transition of the signal from low to ...


1

The short answer is all components in the chain you described have some effect on the acceleration. The CAM software defines the waypoint through which the tool center point passes. (Let us ignore the setting when it outputs the contact trajectory). When the waypoints are defined and the feeds and speed for the segments are set this already imposes some ...


1

On my experience working with stepper motor and CNC shield V3 with DRV8255 motor driver, acceleration and decelaration happen on software side. So I have simple trajectory planner and PD controller to handle the error which produce control signal in form of acceleration, then I simply integral and get the velocity at that time. The acquired velocity then ...


1

The A4988 is an excellent choice to drive a stepper motor. It supports step resolution upto 1/16 of a step and can be set up so that it uses just two of your Arduino's pins. Each A4988 can drive one stepper motor with input voltages upto 35V and current draw upto 2A. Highly recommended for your project. Here is a sample pin-out you could use to drive a ...


1

That is a very good choice since DVD motor operate under 2A. I'm using the very same driver to manage my DVD drivers also NEMA23. You just need to take care about trimming the current limit very well and concern about chinese production because they differ between resistors. Note that the original StepStick stepper driver boards use 0.2 Ohm current sense ...


1

You can do that in Proteus. You can simulate a stepper motor there, but only to see the motion, it is not possible to simulate the speed, inertia, and mechanical response.


1

Here is the response from stepperonline about their closed loop stepper controller. Glad to receive your inquiry. You can't install the encoder on the output of the gearbox. This is uncorrect and forbidden. For the driver can't control the motor The encoder must install on the shaft of motor. Have further question, please don't hesitate to contact ...


1

I am not sure how you are driving your stepper motor. In case you developed your own way, you could connect an analog pin to the wires that drive the stepper motor. These should be able to detect an induced voltage if the stepper is turned without being driven.


1

So how can I connect the step and direction and enable pins of ATMega to these pins of LB1847?! You can't. The LB1847 doesn't accept those as inputs. You'll need to write your own code to send the correct signals to the LB1847. From the LB1847 datasheet, page 6 gives the "Sequence Table" for the first 32 (0-31) steps of a revolution. It looks like you'll ...


1

You can't do position control without position feedback. You need position feedback. Your comments regarding why you're not going to use position feedback ("cumbersome and inaccurate due to vibration") are totally inaccurate. There is no vibration unless you don't mount the equipment correctly. It's not any more cumbersome than anything else. If you want ...


1

The PWM signal should not be the limiting factor in achieving the accuracy you seek. For some applications, PWM signals are chopped > 100 kHz, so, given the correct DSP or microcontroller output to create the PWM, you will have as much control over the power going into the motor as you need. Most of the motion control system I've built have had PWM ...


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