To align the worksheet exactly I installed and red laser diode parallel to the laser beam after the last mirror.

The wiring was easy, I just use an available fan2 connector and the 5V my BTT SKR 2 board offers and connect this directly to the laser diode.

To activate the pin I add in config.g

; Tools --> red dot Laser
M950 F2 C"fan2" Q100                             ; create red dot laser as 2 on pin fan2
M106 P2 S0 C"RED Laser" H-1                 ; set red dot laser to off on startup --> controlled by macros

To use it I create two macros, first LASER ON with the following content:

G10 L2 X0 Y0                        ; Reset workplace coordinates to zero

; Move laser head by red laser offset
G1 F5000 X{move.axes[0].machinePosition + 14.5} Y{move.axes[1].machinePosition + 8.5}

M106 P2 S0.7                        ; switch on red laser diode to 70% brightness

and the LASER OFF which contains:

; move main laser headto current red laser position
G1 F5000 X{move.axes[0].machinePosition - 14.5} Y{move.axes[1].machinePosition - 8.5}

; set the current position as X and Y zero position
G10 L20 P1 X0 Y0

M118 P3 S"Workplace zero set"

; switch of red laser
M106 P2 S0

To find the right values for your offset here is an SVG which you can use to engrave a 50x50mm raster:

To get your values just engrave the raster and then run LASER ON macro, place the red dot in direction where your ZERO is configured (mine is front left) and then fire your laser, then read the offset and change the values in LASER ON and LASER OFF macro.

Hopefully someone else find this feature useful too

@chrishamm tried your fix --> some of the dial buttons are not functional all the time!

After homing Z the nozle is positioned at 5mm and the move down Z-0.05 works one time only and then the Z-0.05, Z-0.5, Z-5 are not working but Z-25 works

--> my bed to have a nice mark now!

@mrehorstdmd
After adding a level shifter from 3.3 to 5V the servo now works, even when there is no GND connection between the board and servo PSU

Jay point me to your reverse protection circuit, but I am based in Austria and need to build that at my own for only my four servos which would cost the same as four 36V 154W MeanWell PSU's which I use to drive them on my KillerBee.

I think a flow sensor and a thermistor would be the best solution, if any of them are triggered the laser should be pause the job.

Same for the lid switch.

@sindarius @jay_s_uk

I grab the latest from here:
https://github.com/Duet3D/DWC-CNC/releases

Awesome!

You dit a great job!

I get the Information that the SKR 1.4T board with his LPC chip do not have a hardware PWM just Software PWM which can not handle more than a few hundred Hz, so I changed the 1.4 by an SKR 2 with n STM chip and now I can run the laser with 500 hz and get this quality when I connect the laser to the bed mos fet which is also software driven:

After reducing the Laser power in Lightburn it looks like:

After changing the laser connection from bed mos fet to the e1heat mos fet which is hardware PWM driven I was able to revert the laser settings to 5kHz and got this result after reducing the laser power again:

This are my Lightburn settings for the result above:

I now also do an engraving test with an picture I found in Internet, the speed limit for the SKR 2 so far seams to be 250mm/s, at 300mm/s the head stops in the middle of an move and at more than that it either lost his reference and hit in my case the right machine limits.

The first 10mm of engraving works as expected even at 500mm/s but then it stops, so this seams for me some sort of CPU power / cache / code issue.

Maybe @dc42 there is some chance to cleanup / improve the code for laser usage beyond the proof of @gloomyandy s test version?

But at 250mm/s I get this engraving quality which looks great for me:

@mrehorstdmd
After adding a level shifter from 3.3 to 5V the servo now works, even when there is no GND connection between the board and servo PSU

Jay point me to your reverse protection circuit, but I am based in Austria and need to build that at my own for only my four servos which would cost the same as four 36V 154W MeanWell PSU's which I use to drive them on my KillerBee.

@mrehorstdmd manny thank's for your reply!

I will test that within the next days and come back to you!

@mrehorstdmd Hello,
I try now to wire up a JMC iHSV57 Servo to an RRF board, maybe you are so kind and help me to wire / set it right?

this are the axis config line:
M569 P0 S0 R1 T4.0:5.0:6.0:11.0 ; physical drive 0 X goes backwards

The board is sourced with 24V, the Servo with 30V.
Wired on the Servo to the board are
ENA+ > ENA
DIR+ > DIR
PUL+ > STP
ENA- > GND
DIR- > GND
PUL- > GND

GND of the servo input is also wired to the signal GND

The servo just flashes in one second interval infinite, the JMC 1.7.6 sw is working either but I have no clue which parameter needs to be set either in the servo or RRF to make it working.

Many thank's in advance for all your support!

@chrishamm tried your fix --> some of the dial buttons are not functional all the time!

After homing Z the nozle is positioned at 5mm and the move down Z-0.05 works one time only and then the Z-0.05, Z-0.5, Z-5 are not working but Z-25 works

--> my bed to have a nice mark now!

To align the worksheet exactly I installed and red laser diode parallel to the laser beam after the last mirror.

The wiring was easy, I just use an available fan2 connector and the 5V my BTT SKR 2 board offers and connect this directly to the laser diode.

To activate the pin I add in config.g

; Tools --> red dot Laser
M950 F2 C"fan2" Q100                             ; create red dot laser as 2 on pin fan2
M106 P2 S0 C"RED Laser" H-1                 ; set red dot laser to off on startup --> controlled by macros

To use it I create two macros, first LASER ON with the following content:

G10 L2 X0 Y0                        ; Reset workplace coordinates to zero

; Move laser head by red laser offset
G1 F5000 X{move.axes[0].machinePosition + 14.5} Y{move.axes[1].machinePosition + 8.5}

M106 P2 S0.7                        ; switch on red laser diode to 70% brightness

and the LASER OFF which contains:

; move main laser headto current red laser position
G1 F5000 X{move.axes[0].machinePosition - 14.5} Y{move.axes[1].machinePosition - 8.5}

; set the current position as X and Y zero position
G10 L20 P1 X0 Y0

M118 P3 S"Workplace zero set"

; switch of red laser
M106 P2 S0

To find the right values for your offset here is an SVG which you can use to engrave a 50x50mm raster:

To get your values just engrave the raster and then run LASER ON macro, place the red dot in direction where your ZERO is configured (mine is front left) and then fire your laser, then read the offset and change the values in LASER ON and LASER OFF macro.

Hopefully someone else find this feature useful too

@dc42 sorry to bring up this rather old topic, but since fast laser engraving is now possible this feature is an other must have for using RRF on laser cutters.

Please include this in the next release.

Many thank's!

@o_lampe no, I am not use M593 currently (https://duet3d.dozuki.com/Wiki/M593)

Would this improve it also?

I now also do an engraving test with an picture I found in Internet, the speed limit for the SKR 2 so far seams to be 250mm/s, at 300mm/s the head stops in the middle of an move and at more than that it either lost his reference and hit in my case the right machine limits.

The first 10mm of engraving works as expected even at 500mm/s but then it stops, so this seams for me some sort of CPU power / cache / code issue.

Maybe @dc42 there is some chance to cleanup / improve the code for laser usage beyond the proof of @gloomyandy s test version?

But at 250mm/s I get this engraving quality which looks great for me:

Today I get an test firmware for my BigtreeTech SKR 2 board to improve the raster engraving quality and speed dramatically!

This is on trotec laser "plastic" aluminium / black 1.6mm

The 500mm/s made with the test firmware and the others below with the stock firmware https://github.com/gloomyandy/RepRapFirmware/releases/tag/v3.4.0beta5_1

With default firmware and 150mm/s on an 70 x 23 mm size work sheet I do get such results:

(each vertical line of the ruler is 0.5mm)

this are the lightburn settings for that:

with the test firmware and at the speed of 500mm/s and changing from LINE+FILL to FILL only as increasing the laser power I get this now:

Here are the lightburn setting for that:

So hopefully this major improvement made by @gloomyandy will be available in the future to the RRF release at least when it is in laser mode!

I get the Information that the SKR 1.4T board with his LPC chip do not have a hardware PWM just Software PWM which can not handle more than a few hundred Hz, so I changed the 1.4 by an SKR 2 with n STM chip and now I can run the laser with 500 hz and get this quality when I connect the laser to the bed mos fet which is also software driven:

After reducing the Laser power in Lightburn it looks like:

After changing the laser connection from bed mos fet to the e1heat mos fet which is hardware PWM driven I was able to revert the laser settings to 5kHz and got this result after reducing the laser power again:

This are my Lightburn settings for the result above: