Hard Limit Switch install/configuration in Lightburn

Hello
sorry for the google translator.

I connected 2 limit switches to the board
(X and Y). But I can’t get the Lightburn one
Performs homing. If I press the switch, I get one
“Alarm1” and must reset. Which settings do I have in
Lightburn make the switches work and
Lightburn does a homing automatically?

The Board is an SainSmart 3-Achsen-GRBL-USB-Treiber-Controller-Board DIY-Graveur-Control-Board für GRBL
the limit switches are switched from com to no

Nice greetings
Torsten

The limit switches need to be setup up in the firmware of the board, not in Lightburn.
You can do that by modifying the $values via the console tab.
$21=1 would switch on the function to utilze endswitches.
You also need to check the type of switch by $5 (0 are normal swiches which are norma open and 1 would be optical)
In addition you need to set the homing direction by modifying $23, this is a bit tricky, as this is done by a bit mask:

Setting Value Mask Invert X Invert Y Invert Z
0 00000000 N N N
1 00000001 Y N N
2 00000010 N Y N
3 00000011 Y Y N
4 00000100 N N Y
5 00000101 Y N Y
6 00000110 N Y Y
7 00000111 Y Y Y

its a bit shiftet, but I guess you can figure it out.
With $22 Homing cycle is switched on.

Thanks for your help
The error messages are now gone.
When I click on “Home”, only the X motor jerks briefly.
Then it takes a moment and I get that
“Alarm 9” error.
I made all the settings as described by you.

I tried the $ 23 mask - unfortunately without success.
The limit switches are connected as specified by the laser board.

If at least the axes would move
I could do something with it, but only the X axis
jerks briefly. Then it takes a moment and I get that
Alarm 9.

Anyone else an idea.

Alarm9 is homing failed. Which is no surprise if the axis are not moving.
Pls. check what values you have for
$24 and $25
These values handle the speed it uses to home.
$25 is the fast homing speed and $24 is the slower one for the second search.
It sound like your motors are stalling.

Pls. Also check $110 and $111, these are the max. Speed for X and Y.
All values are in mm/s

Unfortunately it wasn’t.
I have even reduced the values to 20mm / sec.

Did you start from the middle of the bed?

Yes i have

Could you pls send a picture how you connected the switches to the mainboard? Maybe they are wron connected.

By the way, are you german and in germany? The name of the board is in german.
If so, look into the facebook forum of lightburn. You will find me there and can send me a message per messenger and we can discuss this in german. But if we find the solution, we should post it here as well.


The switches work.
I also shot it at the connection.
No change. Just a short jerk on the X axis.

Switched as in the data sheet of the board.
From Com> NO

Sorry - but i am not at Facebook.

I have a self-made CNC milling machine
(runs under EMC² / Linux) - No problems with the
Limit switches.

I have two 3D printers (ANET A6 and ANET A8M Dual Color):
Limit switches? No problem (operating system: Mariln).
Unless the direction had to be adjusted…

So it’s not my first CNC project.

Whats going wrong ? The board ? The configuration.

If it’s on the board, it would be nice if someone
a board could recommend what would work with a PWM laser of at least 15W (a 10W laser at the moment).

I still don’t have the laser under control via PWM,
but that’s a different topic (the 2W laser also ran without problems via PWM - without Limit Switches).

Anyone else have an idea?

Nice greetings
Torsten

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