Cartesian and Build Environment

[silver2row]

Hello,

I have been learning about iosender w/ my current board. grblHAL breakout board is the board in question...

Anyway, outside of the board, I am trying to get my cartesian laser set up. I am having issues.

First off, part of it is me. My 18" * 18" build environment on the cartesian needs a new set up. The end stop needs to be situated a bit better. So, I can hand click the end stop to handle zeroing the machine for builds...

1. Is there a way to set the size of the machine build environment?
2. This seems like it is needed.
3. I have not found the correct parameters for setting the cartesian build envelope which is 18" 18" or roughly 458mm 458mm.

Seth

P.S. I found the side menu options of iosender. It acts like it will scroll the XY outer perimeter of the build piece but w/out my cartesian 458mm * 458mm, I am sort of lost. Also...

This error: feed rate has not been set or is undefined keeps coming up when trying to maneuver around the build environment.

[phil-barrett]

I'm not sure I fully understand what you are asking. X, Y and Z max travel can be set in Grbl settings ($130, $131 and $132). This is mainly for soft limits ($20). Your limit switches (used with hard limits and homing), if positioned at the point of maximum travel and you have hard limits turned on ($21), will stop the machine when it reaches them. Hard limits, will need max and min switches for X and Y plus a max switch for Z if you use Z. Generally, homing uses min switches on X and Y, max on Z.

The feed rate error is due to the requirement that when you use G1, you also need a feed rate (Fxxxx) as well. So, G1 X10.5 will give you an error but G1 X10.5 F1000 will be fine. Note that once you have specified a feed rate, you don't have to repeat it. After you entered G1 X10.5 F1000, you can use G1 X0 and not get an error.

Also, G0 (rapids) don't need a feed rate specified. It uses your max rate in Grbl settings ($110, $111, $112 for X, Y and Z, respectively).

Hope that helps. Feel free to ask more questions.

Phil

[silver2row]

Hello...thank you. So, when I set $130 X458 and $131 Y458, it sets my boundaries of how far I can travel...okay.

Also, I need to set Feed Rate at some interval. Okay. F500 will accomplish this idea. Okay...

I cut out homing for now b/c of my location issues on the cartesian plane. It seems my Y_Axis keeps stopping short of the homing end stop switch which is the min switch. The X_Axis min end stop works but b/c the Y_Axis end stop stops prematurely, the X_Axis never homes, i.e. hence me cutting out homing for now.

Seth

P.S. What is a normal feed rate for a cheap machine? I have good drivers but my motors are silly and my machine motors can handle the frame easily. The frame is cheap. I have been working w/ this cheap machine to get better acquainted w/ grblHAL and iosender for use on Windows 11 machines.

[silver2row]

Also sir,

I do this...

1. $130 X458
2. $131 Y458
3. G0 Y25 F25

After number 3. has been applied, the machine goes on forever and not just 25mm at a feed rate of 25.

Is this due to not having homing set up and the limit switches being set up?

Seth

P.S. Okay...I set up homing now and my limit switches are working. The machine now has homing. The XY commands still do not listen correctly. I command it to G0 X25 F25 and it moves until the machine hits a non-limit switching part of the machine frame.

Please send guidance. I set up $130 X457 and $131 Y457 and then command the machine after homing it. Blah, I am stuck for now.

[silver2row]

Update

I read one of your articles on your website, sir. Nice! Imperial was used on the software for CAD/CAM while the iosender source used metric. Blah. Okay. I will figure this out. Sorry for harassing you.

Seth

[terjeio]

P.S. What is a normal feed rate for a cheap machine?

Impossible to tell, acceleration plays a role as well the hardness of the material you want to cut, depth of cut and the size of the tool... If not cutting you may try increasing the both the max feed rate and the acceleration until the motor stalls and back off from the values where stalling occurs.

Is this due to not having homing set up and the limit switches being set up?

Not really. G0Y25 commands movement to the absolute position 25mm, how large the actual movement will be depends on the position the movement starts from. If the starting position is not 0 it can be smaller or larger.

Have you calibrated your axes so that steps/mm matches the machine? Most steppers produces one turn per 200 steps. E.g. if you have stepper drivers set to 8 microsteps and a screw that produces 2mm movement per turn then the steps/mm setting should be 200 * 8 / 2 = 800 steps/mm. If the machine is belt driven the math is a bit more complicated.

[silver2row]

Okay...

No, I have not calibrated the machine and I am unsure about the motors so far. I will replace these motors soon.

I will read the info. soon on calibrating my axes and the belt drive math. Thank you. It is belt driven.

Seth

update

I got the machine to listen finally, home, and the laser turned on. Yea boy! And okay about the math portions of the motors and steps per mm. Thank you for reminding me. I come from trying to 3D Print at times. So, I am sort of familiar w/ the lifestyle of motors, steps/mm, and belt driven mathematical calculations for hobs, gears, and belts. Again, my machine is cheap so far.

So, the motors might be 0.9 degree and not 1.8 degree. They are not labeled, cheap machine, and I will need to replace them w/ something more labeled w/ datasheets.

[phil-barrett]

This might help you calibrating. You don't even need to work through the gearing for your belts - just use your initial guess and adjust from there.

Your motors are probably ok and even if they are 400 steps/rev the tuning process with take care of that. In fact 400 steps/rev means that you can reduce the microstepping by half. That, in theory, means you will have more torque at a given RPM. (though it probably doesn't matter for laser CNC with a light load.)

[silver2row]

Okay...thank you guys/gals. I appreciate the assistance in this endeavor. I will go to the grbl site and review things.

@phil-barrett , I am reviewing the docs/blog now. Thank you! I see, I see, I see.

[silver2row]

So, is it $100 X400 and not $130 X400 for stating the maximum travel the X_Axis will handle on my machine?

I see your post here but then read and reread the blog you referenced. Each seem to be different...

Seth

P.S. I just reread it... Sorry. I see now. $130 is for soft limits while setting the soft limits may help, I have minimum hard limits which might be tricky. But I will use $130 X400 for the X_Axis. Again, sorry.

[phil-barrett]

FWIW, to set the X soft limit, you send $130=400 to Grbl via MDI in your GCode sender.

[silver2row]

Right. Okay, I was misreading what was typed out. You are right.