I think you are still missing the point.
Even if the time changes for each movement you will know when a movement is finished. Then it will be time to turn off the laser.
Unless of course the purpose of the exercise is to have the laser ON when the motors are stationary? In which case, how do you determine when the laser has completed its job?
Thank you so much for your answer.
I think I am missing the point, because in my view, the easiest solution is to use a sensor.
Could you help me on that? Because since you and Mike think I am wrong, I think you guys are right.
Here are some other details:
The stepper motors need to deposit one layer of powder into the building chamber (the time to do this is constant, let's call it X). After the layer is deposited, we will manually turn on the laser and it will melt the powder and start to create a part (the time to do this is not constant, because we will vary the power, laser velocity, and other parameters).
After the melting is done, we need to deposit one more powder layer so we can continue the process.
Then, we point the laser to the sensor and restart the movement. Here, the laser algorithm will do this: 1. activate the light sensor and wait for the time X, 2. as soon as X seconds is passed, the laser will melt the powder again. Then, this process happens until the part gets built.
With this configuration, it does not matter how long the laser melting time is, because the axis will only move as soon as they receive the signal from the sensor.
Okay, I know that we could integrate the arduino into the laser so that everytime the laser finishes lasing, the axis movement starts again.
But don't you think that it is easier to integrate only one sensor into the arduino than it is to integrate all the diffent types of laser machines we will be using into the arduino?
I think that may be the main question.
You have said what you want to do but not made a case for the sensor.
So what action do you do to point the laser? That same action can just be used to set off the system for the next layer. Their is no need to use a sensor. If that action is a command to "go point at the sensor" then that command could be just interpreted as a "start next layer".
By the way, the real name for the selective melting you are doing, is "sintering".
Thank you for your answer. As I wrote to Robin, I think it is easier to integrate one sensor to the arduino then it is to integrate all the lasers to the arduino. Don't you think that?
Also, saying the SLM is SLS is like saying that Milling is Machining. But the Additive Manufacturing Community uses SLM for the process that I am talking about (the one in the picture).
Robin and Mike, thank you for your time and your help, and if I you think I am out of my mind and it's easier to integrate the lasers to the arduino or I don't need any of that, please say so, because I am completely new to stepper motors.