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Messages - rpt007

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LaserGrbl / Re: LaserGRBL doesn't switch the Laser ON
« on: January 17, 2018, 04:09:51 AM »
Eleks have already fixed the issue and acknowledged it was a poor design

I only got last week an SE board as I had already understood from some comments in the forum, that the Eleksmaker guys pretended to have fixed the issue on the hardware side and I want to build a bigger machine now.

Didn't have the time yet to test it a bit more with different software but T2Laser switched the Laser ON ...

To avoid getting an "old" board from stock I bought it directly from Eleksmaker to hopefully get the SE board with the fixed design and NOT via a third party seller. Unfortunately they apparently keep selling the old stuff as my board came still with the LaserON problem onboard.

Will contact them and ask for a fix - maybe I can do it by myself having an electronic laboratory at hand.

LaserGrbl / Re: LaserGRBL doesn't switch the Laser ON
« on: January 16, 2018, 12:20:13 PM »
I fixed the LaserON issue with adding a 10k pull down resistoron my l7 board as I want to use T2Laser once having paid for the license and while it has some features which LaserGRBL not (yet?) has.

My "usage sequence" is always like follows:
1. powering up (i.e. connecting the USB cable with my Laptop) while the control board is still OFF
2. starting the application
3. only then I switch the board ON
4. preparing the Laser operation
5. etch / burn

So I take care to not run into the boot sequence of the Arduino at the very start.
But, as stated above: after that sequence T2Laser and LaserGRBL behave differently on my machine and T2Laser powered the Laser ON for a couple of seconds when returning from the Laser control window to the start up window. Thus I started this thread stating that there must be a different handling of GRBL by the 2 applications.

Nevertheless all is ok now having applied the pull down resistor to my L7 board.
BTW: I also fixed the nerving hiss of my motors when T2Laser starts or switches between its two main windows by soldering a pull up resistor from D8 (=Enable Pin for the drivers)  to +5V.
See my pictures in this thread:,2942.0.html


T2 Engraving / Re: Eleksmaker L7 - 2sec Laser ON
« on: January 13, 2018, 06:18:34 AM »
I used the unused pin connector on the L7 board to test if and which resistor value would work.
First try was with a 10k resistor and this already fixed my problem. I could switch back and forth between the T2Laser main windows and the laser never came ON.
So I soldered a little adapter to make the mod easily removable if there would be a need in future. See attached picture1.

Having succeeded with the laserON issue, my engineering mind got challenged to go a bit further. At the same time when I switched between the main application screens of T2Laser I always heard my stepper motors hissing for about the same time that the Laser came ON (well, in my case only when closing the Laser Control window). The hissing of the motors occurred in both directions (from main window to Laser Control and back). Thanks to George's reverse engineering schematics of the L7 (see,523.0.html) the cause was evident. While the GRBL environment in the Arduino is settling to stable values apparently a lot of pins are floating if not being bound to a logic level via pull up or pull downs.

The stepper drivers are all using the same Arduino pin (D8 = physical pin #11) for being enabled (ENA = LOW!); so during the floating period (at least on my board) the ENA pin is or gets LOW and thus enables the motors. Luckily there is no step/direction coming up which would move the axis. To stop the ENA pin floating I simply added a 10k pullup resistor which keeps the pin in logic HIGH. The simplest way without having to unmount the pcb board was to use the +5V pin on the ICSP header (=pin#2) and D8 on top of the Arduino board. See attached picture2.

Now I can switch back and forth without LaserOn and without the steppers hissing (which means around 1A current flowing through them). The only sound which can be heard is a very short sound when the steppers got intentionally enabled by GRBL.

Laser Safety / Re: The "Ferrari" of safety ...
« on: January 13, 2018, 01:35:55 AM »
I roughly calculated the additional cost by finding the most economic sellers in Germany and ended at about 200 - 250.  But it is a professional investment in your health (smoke, laser ray). Once completed you will be protected against 99% of potential risks while operating your machine.

A wooden alternative would also be around 100+ incl. fan, hinges, power supply and some metal plate etc. As my health is worth that little investment I will copy the main construction for my laser.

Laser Safety / The "Ferrari" of safety ...
« on: January 12, 2018, 12:50:18 PM »
If you want to improve your safety around your DIY Laser machine, have a look at: and see what is possible.

Explanations in German, but the pictures illustrate what is going on.

LaserGrbl / Re: LaserGRBL doesn't switch the Laser ON
« on: January 12, 2018, 12:38:49 PM »
I suspect it has something to do with the particular MOSFET on the board.

But it is a bit strange that LaserGrbl doesn't have the same issue with this board as T2Laser has.  I have both apps on the same Laptop and can switch back and forth from one app to the other without changing anything on the hardware connection side. So LaserGrbl somehow does something different so that the Laser MosFET is not triggered.

If I am not mistaken, one can find the source code of LaserGrbl on GitHub; so if somebody with more software knowledge than me could analyse why LaserGrbl seems to be a bit more clever than its competitors.

LaserGrbl / LaserGRBL doesn't switch the Laser ON
« on: January 12, 2018, 05:38:01 AM »
... my headline might be a bit misleading as I am not reporting a software failure.
Quite the contrary:

I am using currently an Eleksmaker L7 board (no mod with a pull down resistor yet).
As others I do have the issue with Eleksmaker's software and also T2Laser that the laser is switched ON when starting or closing the apps.
Before modding my board with a recommended pull down resistor, I replaced the laser with a blue LED (and a 1k resistor in series) to avoid too much burning innocent material to test the different software packages to make sure the LaserON problem is/is not software GRBL related, as read here and in other forums.

In my given configuration I got the following test results:

1. The Eleksmaker app switches the LaserON when starting up and when I close the app ...)
2. T2Laser has the LaserON problem (1-2sec) when switching from the LaserControl window back to the initial screen (only that direction causes a LaserON issue in my configuration, others report the other way round or in both directions, when switching between the windows).
3. LaserGRBL does NOT switch my Laser ON, neither on startup nor when closing the app - without having changed anything on the hardware side!

So, at least LaserGRBL is apparently configured in a way that it overcomes the floating issue, which is due to the boot up sequence of the Arduino. So a mod is not necessary for users who only use LaserGRBL.

My next step is to solder the pull down resistor to the L7 board to see if I can persuade T2Laser to leave the Laser OFF when returning to the main window and test, if it has any impact on LaserGRBL. Eleksmaker software has already been sent to the bin.

T2 Engraving / Re: Eleksmaker L7 - 2sec Laser ON
« on: January 10, 2018, 03:00:56 PM »
OK, understood.
Thanks for your reply; will solder a 1k resistor and see what happens. Will report back here.

T2 Engraving / Eleksmaker L7 - 2sec Laser ON >SOLVED<
« on: January 10, 2018, 07:13:15 AM »
Hi all,

I carefully read the threads about the Eleksmaker Mana SE "Laser ON" fix by soldering an appropriate pull down resistor to overcome the floating state of the Nano when powering up.
My L7 board behaves like this during the startup and operation sequence:

1. L7 board is OFF
2. Start T2 Laser application (Main window)
3. Load/manipulate object to be lasered; save G-Code
4. Switch to "Control Laser" window / setup workpiece etc. and start lasering

Up to this point everything works as expected and the Laser behaves like it should imho.
But - if I forget to switch the board OFF and go back to the startup window of T2Laser -> Laser switches ON for about 2sec and burns in "zero-position" into the workpiece.

Besides of hardware workaround - isn't that also possible to maintain the Arduino in a safe Laser-control status?
Or is the control for these 2 sec not possible?

Power ON: Laser is always OFF while Arduino and

T2 Engraving / Re: vacation
« on: January 07, 2018, 05:09:38 AM »
Zax, I join in and thank you for all your help in 2017 to get me going.

Keep your good work going on in 2018.
But before jumping back into our day2day nitty gritty issues - have fun on your vacation and enjoy the computer-less time (if possible).


T2 Engraving / Re: Waste Board Grid
« on: January 07, 2018, 05:01:16 AM »

just an idea to improve the "Tick" thing.
If it would be possible to visualize the "Tick" / "Un-Tick" immediately, just when you click on an option in a dropdown menu, it would be more intuitive (=visible), THAT you either selected or unselected an option.

With the current software you have to close the dropdown and open it again to see, if the selection process really happened and what finally got activated or de-activated.



Adjusting the stepper motor current has had a sticky thread

Thanks for the information; as I am just beginning to rush through this forum, I didn't (yet) come across that thread.

Well a new 3-axe board cost only 30 USD

Well, if you trash 10 of them by not paying attention to the current limit settings it's already 300 bucks.
And: My Murphy's law says: the probability that you trash something gets higher the closer you get to a weekend where you can't quickly buy a replacement ... ;D

Could you solve your problem already?
If not, maybe the current adjustment of the motor driver(s) causes the problems.

I am a bit astonished that apparently there is no information about how to adjust the stepper motor current on the drivers which always should be the very first thing to do when using an A4988 (or the better DRV8825). Pololu has issued some very helpful information about how to set up the current limits - here is the starting point:

Before you follow those instructions you should check your motor's max. current (read the stepper motor's datasheet for that information).

Maybe this helps to avoid either killing your motors by burning them with too much current or not moving them by too less current flowing.

T2 Engraving / Re: T2Laser installation issue
« on: December 26, 2017, 01:35:28 AM »
It's actually a rare issue, I'm not sure what causes some computers to have this setting but I will add it to my website.


it has to do with the initial security level setup when you install Windows.
I upgraded from Win 8.1 to Win10 and there might have been a question by the setup routine what security level I would prefer.
Normally I take the strongest one but never had any issues with other installations as the installation process normally asks for temporary admin rights.

After any installation I always return to the default user level without admin rights. My observation is that most of the people who have run into trojan and other malware issues are running their machines on admin level all the time - unfortunately Windows comes with default user on admin level ...


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