Hi

Thanks for the replies, whilst I await spare components to replace burnt out ones I have purchased a Maestro.

I noticed this in the Power Wiring section.

“The positive wire from the power supply goes to the terminal marked + which is the one nearest the stepper motor connector side of the board. “

The last part of this statement no longer applies as a comment, as the Maestro Vin is the other way round.
Where the Vin - pin is nearest to the stepper side of the board on a Maestro.

Lloyd
P.S Should I have created a new topic for this enquiry?

Hi

I have removed U2 and there are no shorts between any of the pins.

But me thinks this one, U11 has gone as well.

So, In theory I can feed 3.3v from the external connector for the rest of the board and it might work.
If it does not work then I can remove this chip. I wont need 5v and then the Bed, E0 and E1 PWMs will be inoperable.

But, at least if the board still works after that then I could move this board onto my laser cutter as a motion control system.

3.3v from my PSU is the next step with current limit.

Lloyd

Hi
Thank you for your words of sympathy.
I had indeed seen the USB isolators described in the article and may purchase a few.
I don't do that many USB upgrades and use the web interface for control.
So, I might just stick to using a laptop on battery power.

I have checked U2 and it has blown, massive bubble in the casing.
Without thinking you might potentially offer a solution I have purchased a replacement U2 to see if this is the only component gone.
They are only 10s of pennies after all.

Also, the current melted the track around the USB connector destroying the ground wire.
It might be a good idea to make this a bit more meaty on future PCBs
I also removed the connector, so as to remove any potential as a short.

I might apply 3.3v to the expansion strip to see if the board will boot. If this is OK, then I will refit U2 otherwise I will discard the board as failed.
Unfortunately, my soldering skills were not so delicate with the USB port and took the ground pads of the PCB on the connector side.

If the board is alive after the previous described attampts at repir and if I ever need USB in the future then I will apply wires to the 2 resistors for D+ and D- and knock up a temp USB connection with a cutdown USB cable.

If you wouwld like to see pictures for forensic study then I can post some.

Hello David.

I recently had cause to reinstall the firmware on my Duet2 1.04 board.
So, I re-read the page https://duet3d.dozuki.com/Wiki/Installing_and_Updating_Firmware for guidance.
The Duet2 was already installed in a printer and so powered by a mains PSU.
The printer was powered off at the time, I plugged in the USB cable and performed a Bossac install.
Without thinking I turned the printer on to check if the install had worked using the web interface.

At that moment in time the magical whiff of blue smoke along with a crackling sound was heard from the USB connector.
Power was rapidly turned off and the USB cable removed. Which was extremely hot to the touch.

Without understanding in full the ramifications of my actions and to recover my printer from a now fried Duet3 I retreived a Duet 06 board and tried to do the same upgrade this is now toast as well.

Further investigation revealed an informative page on the duet3d site https://duet3d.dozuki.com/Wiki/USB_ground_loops which details ground loop effects in the USB cable when two maisn powered pieces of equipment are connected. I beleive this was my problem born out by the very hot USB cable and melted pins on the USB connector.

Please add a mention of this danger and URL to the section at the top of the 'installing and upgrading firmare' pointing out this danger.

I hope by adding this warning I can prevent others from doing the same as I have.

Needless to say I now have a Maestro on its way from oozenest.

Lloyd

Hi David

The M3/M5 commands work and I can now cut using those.
I have also worked out the G2 arc command and this works well as well, firmware version 1.20 for reference.

Would upload a picture but not sure how to do that on this site.

Lloyd

Thanks I will try that tomorrow.

No I was hoping that once I had the vector stuff going I could work out how to PWM the heater0 output and then use that to vary the power to the laser. At least that would then give me the ability to cut and engrave at different power levels.

To engrave bitmaps would need some sort of work flow that will enable me to move the head at a fixed speed and vary the heater0 PWM as the head is moving, or just do lots of small movements at different power levels, "that would just be messy".

My work flow for cutting and vector engraving uses Fusion 360 CAM with a gcode plugin, I expect to have to program a new plugin based on the one I am using to optimise the gcode output to the Duets gcode.

Lloyd

Hi everyone

I have one of the Classic Blue and White 60W Chinese laser cutter/engraver.
The Chinese controller board eventually failed and I decided to upgrade it with one of my Duet 0.6 boards.
I have had some success with the Fan0 output via the M571 code, but I would like to investigate the RepRapFirmware using the Laser mode as described on the gcode for Duet3d wiki page.

I have would like the following functionality X axis, Y axis, an enable pin (FAN0-) along with a correctly configured PWM pin not sure which one yet, maybe a heater.

So I have a standard setup for cartesian XY motion with endstops and a diode from FAN0- to laser PSU IN pin.
This has been proved to work with M571 style configuration.

So, I want to use the following to allow the FAN0- pin to be used as an enable.

M106 P0 I-1 ; disable Fan0 and allow it to be reallocated
M452 P20 R255 F200 ; Enable laser mode, use pin 20 (Fan0)

Is this correct and should I then be able to see the FAN0- output go on/off when ever there is a G1 controlled movement?

I also expect to put a M4/5 commands around the gcode to enable the PWM of the pin and so its strength
M4 S255 ; PWM full strength
M5 ; PWM off

Does this sound right? at the moment after homing the head the laser is not fired when I manually issue the commands from the console:

M4 S255 ; enable laser at full strength
G0 X0 Y0 ; Move without firing
G1 X0 Y100 ; Move whilst firing
G1 X100 Y100 ; Move whilst firing
G1 X100 Y0 ; Move whilst firing
G1 X0 Y0 ; Move whilst firing
M5 ; disable laser

Any input would be useful.
Thanks

Lloyd