RepRap to CNC Laser Engraving machine

RepRap become a CNC Laser Engraving machine and succeed in laser on off control via M104 code.

Video:
[www.youtube.com]

1.6W 808nm Laser was used. It can burn the surface of wood in 5mm/s feed rate.

What laser unit and driver did you use and how did you mount to the reprap?

Draw and print a laser mount, lens mount, and mount on X-carriage.
A 1.6W 808nm Laser with TTL control was used.
Lens is 20X convex lens.
The focus is about 40mm.
Please find the attached photos.

thanks for the info and the nice pics.

I have some questions though

a) where did you get the focusing lens
b) how did you drive the on/off of the laser? (both electrically and from the g-code command)
c) what firmware are you working with and what tweaks have you done?

... for this NIR-diodes you can use normal lenses without anti-IR-coating - he used a 'folding magnifier' (Einschlaglupe in German)

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

The lens brought from common hardware shop and cost around US$2. only. But the focus does not become a "Point" due to the bad quality of lens. Need to buy another high quality infrared convex lens. I will buy the lens from "TaoBao" (Online shopping in China).

My laser have TTL control contact point. This contact point connected to the "extruder heater" 12V supply (need to disconnect existing extruder power supply). When "heating up" the extruder, off the laser. When "not heating up" the extruder, on the laser. But this type of On/Off control similar to "NC" condition. As a result, the laser will be turned on when standby. I will connect a "NO" relay between the laser and supply later to improve the control.

I am using skenforge to generate G-Code for the laser cutting and text engraving.

The command code of exturder heater is M104 S?. ? = set point. The G-code need to replace the M101 & 103 to M104 S0 & M104 S255.

Repsnapper used to control the RepRap.

... don't blame the lens for the bad focus shape - it's most common the diode when using the direct output.

Comercial diode heads use bar-lenses and/or prisms for beam shaping, as diodes have two different diverging optical 'axes' resulting in a stripe or elliptical focus when 'only' focussed.

I'm using high power IR-diodes with an attached glass fiber with 0.1mm core diameter. Here it's enough to focus the output to a perfect round spot ... but the diameter of the spot is roughly in the diameter of the fiber core, so 0.1 to 0.15mm best ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Thanks Viktor,

Here is the parts of laser clip:
[www.thingiverse.com]

Cho.

but viktor by forcing the laser through the glass fiber, you get a nice 0.1 focusing range which is great considering that most 445nm focus around 0.4mm with the g2 lenses.
so you suggest using a glass fiber as a solution? does it consume power from the laser?

... refocussing the laser into the fiber will loose a great part of power - my IR-diodes are equipped with the fibers by the manufacturer directly at the emitter, so much lesser power losses.

But 0.4mm for the 445nm diode sounds terrible! - I've focussed my 445nm-diode with a blind and bigger lens to the same 0.1 to 0.15mm as with the IR-diodes

My estimation is, that with a 1:1 refocussing (e.g. 20mm distance from emitter to lens and from lens to focus) you're a bit bigger than the emitter size .... and with a shorter focussing distance than from diode to lens you can even get smaller than the emitter diameter.

I have a 808nm-diode with a 0.05mm fiber refocussed to 0.05mm too -- and a 'serious' fiberlaser with a fiberresonator with a core diameter of 0.05mm and 5m length, that can be refocussed to 0.005mm! ... but this is a totally different case, not comparable with diode-optics ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

I use this lense for 445nm diode:
[www.ebay.com]

Beam is focused about 6.5cm distance, and when I cut paper, cutted line is about as thin as a paper or less (under 0.1mm) .
Mine mechanics vibrates and wobbles more than that
Focused beam shape is indeed a stripe.

... with 65mm focus distance to maybe 10mm distance from diode to lens you'll get a really bad 1:6 refocussing - e.g. with 0.1mm emitter your focus diameter will be something like 0.6mm with all the bad characteristics (stripe/bar) visible.

My heads have bigger lenses with maybe 20mm to 30mm (or 1:1,5) or better, so the stripe-image when direct refocussing a diode without attached fiber will be only slightly bigger than the emitter size ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

But anyway it works
1.75 mm balsa is cutted trough about 10 mm/s.
And the "stripe" is very small, but I know it still exists.
Is it better to be longer distance focus or shorter with that small lense?
I can tune it at some range shorter to eternity.

... try to reduce the focus distance ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

below_cho Wrote:
-------------------------------------------------------
> RepRap become a CNC Laser Engraving machine and
> succeed in laser on off control via M104 code.
>
> Video:
> [www.youtube.com]
>
> 1.6W 808nm Laser was used. It can burn the surface
> of wood in 5mm/s feed rate.

Wow, looks realy good

Edited 1 time(s). Last edit at 02/09/2013 04:26AM by photonix.

Does the engraving part use x/y movement as a desktop printer (draw lines and pulses)
Or does it engrave as a plotter? I would like to have it draw lines,over the x axis and then take a y step
Down the material and draw a line over the x axis again. Like a desktop printer. Is that possible ?

Hi Hessel,
yes it's possible:
For your lines, just use INKSCAPE with the GCODETOOLS.
In Inkscape create a tool for RepRap usage.
Draw your shapes and then go to GCODETOOLS -> AREA -> and then to the tab FILL AREA, choose your settings and press generate. The generated GCODE should work for your demands

... tested a 830nm-diode with 0.05mm fiber and powers of roughly 0.5Watt and 1m/min speed for cutting a 0.3mm thick black PVC sheet:

- burning the traces with 0.5Watt and 1m/min, exhausting the fumes through a charcoal-filter:





- finished after 16 minutes (all the small gold-coins):





- partially cleaned:

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

... this is the dragon-tatoo in the 'original' size on a 300x210mm big plate for a crackerbarrel stand ... have to mill the stand to finish it ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Quote
photonix
below_cho Wrote:
-------------------------------------------------------
> RepRap become a CNC Laser Engraving machine and
> succeed in laser on off control via M104 code.
>
> Video:
> [www.youtube.com]
>
> 1.6W 808nm Laser was used. It can burn the surface
> of wood in 5mm/s feed rate.

Wow, looks realy good

Do I see the Z is lifting between cuts? It may be an illusion, but it appears to me to have a Z lift.

---

[regpye.com.au]
"Experience is the mother of all knowledge." --Leonardo da Vinci

... yes, it lifts in Z -- this is common for milling software as 'Z-clearing' ... in my software I have regularly to set this 'clearance' to zero or it will do the same ...

---

Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Hi all, what kind of software I can use for convert a picture to a reprap compatible gcode?
Thanks.

---

Motedis_kossel delta printer
Ramps1.4 for Due