Ramp up/down CO2 power output at corners - in sync with acceleration

As my laser tube ignites beginning with 8% power and the movement
at the beginning accelerates for the first millimeters and slows down
at the end ==> the darkness at both ends looks too strong.
This effect shows especially with thin plywood or thicker paper.

How are the Lightburn parameters correlate to the Ruida parameters,
and where can the speed or acceleration synced to the power output?

You description doesn’t include if you are doing a scanning operation or a vector.

If you’re scanning, the Ruida will make sure the head is over the image before it lases.

If you’re doing vectors then the min/max on the layer and the start speed in the controller will determine how power is applied…

Any speed <= start speed, you get min power…

As far as I can tell, this graph shows how that’s changed depending on settings.

Does that help with the question?

:smile_cat:

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Yes - that’s a good advice!
I will experiment with start speed and acceleration values
for the RUIDA controller settings in LightBurn.
For line drawings and line cuts on 3mm plywood
I’m using 80 mm/sec speed and 10% of 60W for lines
and 40% of 60W for cuts (2 times to reduce dust).
Up to now the first and last half mm is too strong with my settings, yet.



Also tricky with lines on thick paper:

I will try to set different valus for RUIDA settings and min/max speed to test.
Ruida_Settings_Min+Max+Start_Speed

I usually set my start speed to around 5mm/s

image

Let us know how it works out…


The lines look rather thick, like out of focus thick… is this intentional?

:smile_cat:

The thickness of the lines may be caused by magnification/scale of photo.
Another factor could be that the airflow from compressor thru the nozzle
could be a little too weak - especially when burning wooden material.

With the new setting of START SPEED it looks like this on paper:

What I’m still struggling with is the setting of MIN POWER and MAX POWER.
When cutting a line in Plexiglas (Polymethylmethacrylat, PMMA) the ramp
at the beginning and at the end is extremely steep, while the cutting depth varies a little. (Settings: 10mm/sec with min. 8% and max. 70% power)


OK with this slow speed. And I’m not a physicist nor RUIDA engineer who can calculate the theoretical settings for the values of acceleration to get a constant power per square mm over the whole contour on paper.

==> But I’m happy already with the output by now.

Probably I should get deeper in the dependencies of the settings in the RUIDA controller…


Over all it makes fun to work with LightBurn software as one can get faster results with less circumstances than with a CNC milling machine.

Ditto - :poop:, I’m just guessing myself :crazy_face:


Not sure what I’m looking at in the photo other than a piece of acrylic… I know you know …

What does the artwork look like and mode are you in, line/fill?

:smile_cat:

OK - I should explain the power-timing ramp example a bit more precise.
As I’m also only guessing it is not so exact by now :wink:
2024-05-06_Power_Ramp

And the side view of the Plexiglas sheet shows some varying effects.
So cutting Plexiglas seems to be best with min and max power to be equal.
A different power setting for both parameters makes more sense for me when engraving prictures.

With Plexiglas I’m using line drawing, engraving and line cutting in three steps.


Here it is not easy to set the origin right after reversing the material.
So I have fun to make some experiments…

If you’re using image or fill, minimum power is not used, only in line mode is minimum power used…

If you’re engraving into the plastic and not through, how are you setting up your machine?

Trying to figure out how you are making the parts with depth…

If you don’t mind posting your .lbrn2 file, I’d like to take a look…

:smile_cat:

For creation of illuminated knobs I used original Plexiglas 4 and 6 mm.
Other translucent material showed irregular edges. And using PVC
may be dangerous to life. I used clear or opaque Plexiglas to test.
I spray-painted the front-side two times (three times recommended)
with the letters to engrave later on.


KeyCap_02.lbrn2 (6,8 KB)
Key-Schrift.lbrn2 (62,6 KB)

Engraving the backside led to 2 mm depth. Beside the challenge of
positioning it centric it is critical to avoid liquefaction - especially when
using OFFSET FILL method. So several pathes with lower power
and pauses between the threads may deliver cleaner results.
The illuminated switch should fit to the backside. And PMMA tends
to melt around 100 degrees Celsius.
Engraving the backside delivered 2 mm depth.


To glue two pieces of PMMA with superglue worked but showed cracks.
Now I have put ACRYFIX glue in a syringe what works good.

Cutting in PMMA is much stronger to have equal values for MIN POWER
and MAX POWER. And if the edges are burned stronger because
of speed acceleration and deceleration does not matter.
This is different when drawing lines on paper or wood.

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