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Topics - rpt007

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General Discussion / Any CETUS 3D users here?
« on: March 05, 2018, 03:59:49 AM »
Hi all,

I recently bought a Cetus 3D MKII printer. I am very happy with the first prints. They look somehow better than the pieces I saw from my neighbour's MakerBot, which is around 10times more expensive ... (You can imagine the jealous expression in his eyes).
The only thing I am not happy with is that the Chinese manufacturer uses a closed source controller, so the Cetus can't print G-Code oob. But I am waiting for the delivery of a smoothie board which will serve as 1:1 plugin replacement board. I expect a bit of tweaking to get the new board work with a 3rd party slicer, so I was wondering if somebody here has already done something  similar with his Cetus and share the knowledge and experience.


T2 Engraving / Prevent fading by inserting cool down pauses
« on: February 20, 2018, 03:55:21 AM »
Hi all,

triggered by the discussion here:,2994.msg34602.html#msg34602 I think that fading most likely has two issues (provided that there is no mechanical problem on parts of the axis - which leads to higher friction and the stepper drivers draw more current):

1. overheating of the laser driver (if the heatsink - if available at all - is too small and can't transport the heat from the diode)
2. weak power supply, which isn't able to deliver enough current over time and when more power is drawn by the drivers when friction increases

Question @Zax: Would it be possible to put in "user configurable cooling down pauses" into the "normal" g-code, similar to the feature built-in T2Laser when preparing multi-pass cuts? E.g. after every 5min of sending code to the laser a cooling down pause of 2-3min, continue for another 5min, pause etc.

Hope, my GEnglish is understandable for native speakers.


EleksMaker Mana SE / Mana SE modifications
« on: January 29, 2018, 09:36:55 AM »
I know, that this topic is not new, but I thought I could give new users a short and comprehensive idea how to modify their Mana SE boards in order to
install some remedies to the problems when the Arduino Nano's pins are temporarily floating (e.g. when switching between T2Laser's two application panes), so

1. solve the LaserON problem (10k resistor between GND and S-pin)
2. solve the hissing of the motors (they get shortly enabled = get current flowing through their windings, luckily without getting DIR & STEP pulses) by a 10k resistor between +5V and D8).

I also hotglued and soldered male connectors to the board to wire 3pin homing switches (the ones which come with the LEDs), so that they are connected to +5V, GND and D9 of the Nano. You could also just use GND and D9 when using switches not soldered on the board with an LED. In the case that you are using these LED equipped switches +5V is needed and then you MUST REMOVE the NC-pin of the switch!! see:,1494.msg21588.html#msg21588, reply #77.

In the first pictures you see the modified homing switches which I use and a blue LED with a 1k resistor in series, plugged into the motor output connector. This allows me a very safe testing instead of having the laser connected all time.

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 / 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 / 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

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