GRBL Settings

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sanremo
Messages : 20
Enregistré le : 16 avr. 2021 19:53

GRBL Settings

Message par sanremo »

Hi,
I did all steps building the machine, made the main checks for movement and everything works fine as well as I see for the first time.
Except the speed and homing!

Right now I had to setup the GRBL settings and I'm not sure if everything is correct and in this case I want to ask for a basic check.
Reason is I do not understand all of them, even though I read the Grbl v1.1 Configuration on Github many times.

1. Speed:
Cause I build the machine with different stepper motors and stepper drivers as usually (They were include on a complete machine part set)
I had to try out the parameters for steps, max. rate and acceleration for many times until the motors move the desired length.
Now it works but the machine movements are very slow, especially in X and Y axis.
The suggested value in the manual of "4" for the microsteps was not possible with my stepper drivers and I had to encrease them to "32".
I want to stay with the microsteps as low as possible but with values of 4, 8, or 16 microsteps the motors do not move at all or very slow.
What is the right way or parameter to increase the movement speed?

2. Homing
I do not understand the set-up and starting procedure of homing? How can I do that :?:
And I do not even know if the parameters $22 - $27 are correct or not?!

My Grbl configuration is enclosed.
Thanks for help.
config.jpg
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mstrens
Messages : 2611
Enregistré le : 27 févr. 2018 12:58

Re: GRBL Settings

Message par mstrens »

Your values for $110 and $111 are quite low.
You can try to increase them to 5000.

For $27, if you do get an alarm 8 when you perform a homing, you can keep the value 1
If you get an alarm 8, then increase the value up to 2 or 3.
sanremo
Messages : 20
Enregistré le : 16 avr. 2021 19:53

Re: GRBL Settings

Message par sanremo »

Hi,
okey, thanks for help.
I'll try the higher values.

Regarding the homing. I do not know the setup sequence of homing?!
Just push the button "Home" and the machine make the rest for itself?
I've read the instructions for $23 "homing dir invert" and it tells me machine is moving in positive direction to locate zero-position.
My limit switches in x is on left side (means for me in negative direction), in y in the front (also negative direction) and z on the top (positive)
Will this work or is here anything to change?

Thanks
mstrens
Messages : 2611
Enregistré le : 27 févr. 2018 12:58

Re: GRBL Settings

Message par mstrens »

I expect you have to use $23=3
See here the doc
https://github.com/gnea/grbl/wiki/Grbl- ... nvert-mask

here an extract
By default, Grbl assumes your homing limit switches are in the positive direction, first moving the z-axis positive, then the x-y axes positive before trying to precisely locate machine zero by going back and forth slowly around the switch. If your machine has a limit switch in the negative direction, the homing direction mask can invert the axes' direction. It works just like the step port invert and direction port invert masks, where all you have to do is send the value in the table to indicate what axes you want to invert and search for in the opposite direction.
sanremo
Messages : 20
Enregistré le : 16 avr. 2021 19:53

Re: GRBL Settings

Message par sanremo »

Hi,
first, I increased $110 and $111 - it works. Machine is fast enough.
Thanks for the tip!
Homing sequence is also fine.
Machine stops ca. 3mm before the switches after pushing them in the front left corner.

Okey, but now I have the next problem with the z-probe.
After touching the probe, machine stops, has an Alarm and is locked.
Display tells:
4. Probe init fail
9.Locked (Alarm or Jog)

Whats the problem?
sanremo
Messages : 20
Enregistré le : 16 avr. 2021 19:53

Re: GRBL Settings

Message par sanremo »

Problem solved!
I think it was a missing contact on the z-probe.
Now it works!

Thanks!
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