[pedroman]

Everyone here has heard my story about the laser I purchased via Frank in Texas from Rabbit Laser in China. The only real downside outside of the software was that my spare tube that I ordered came in busted (poor orientation in the box) so I have had no spare.

Well Frank came through along with a new company Dean at www.the-lasersedge.com who is reselling the Rabbit line here in the states. They had ordered several systems and had a replacement tube shipped with them into the US for me. The tube was REALLY well wrapped, shipped standard FedEx Ground and arrived in one solid piece! THANK YOU THANK YOU THANK YOU!!!

This really goes far proving that Frank, Dean and Rabbit are serious about taking care of the US customer base. I can't tell you how pleased I am with how it worked out. Frank if I can help you in any way please let me know.

My nickel recommendation for what it's worth but I'm HAPPY!

Pete aka Pedroman

[ArturoV]

Everyone here has heard my story about the laser I purchased via Frank in Texas from Rabbit Laser in China. The only real downside outside of the software was that my spare tube that I ordered came in busted (poor orientation in the box) so I have had no spare.

Well Frank came through along with a new company Dean at www.the-lasersedge.com who is reselling the Rabbit line here in the states. They had ordered several systems and had a replacement tube shipped with them into the US for me. The tube was REALLY well wrapped, shipped standard FedEx Ground and arrived in one solid piece! THANK YOU THANK YOU THANK YOU!!!

This really goes far proving that Frank, Dean and Rabbit are serious about taking care of the US customer base. I can't tell you how pleased I am with how it worked out. Frank if I can help you in any way please let me know.

My nickel recommendation for what it's worth but I'm HAPPY!

Pete aka Pedroman

Pete,

I wish I was in your shoes. I have had some problems with my machine since the start and I am wondering if you ever had problems with your motherboard? Can you tell me a little more on your machine? I still cant get it to work properly. I have problems with the location of were the laser begins. It doesnt want to start were I have it in the drawing. Can you help me?

[lamicron]

Arturo, what machine do you have? Try to reset the software,sometimes it does'nt get all the files.. if you want I have other software,you can give a try..

[ArturoV]

Well got it going!
Works great.

Is there any way I can send grayscales images to the lasercut software?
It only recognizes 2 bit images( black/white)?

thanks,

Arturo, what machine do you have? Try to reset the software,sometimes it does'nt get all the files.. if you want I have other software,you can give a try..

[lamicron]

Try to export it, not save (from corel) in .AI and after import it to lasercut . Also can do it to PLT.
Of course you need AI installed in your PC.

Luis

[ArturoV]

Try to export it, not save (from corel) in .AI and after import it to lasercut . Also can do it to PLT.
Of course you need AI installed in your PC.

Luis

I only export from Corel (laser doesnt work from corel) to lasercut 5.0 but still get only 2-bit bitmap error. I guess It cant read grayscales? Any other alternatives to get grayscale images engrave?

[lamicron]

I have this instructions, from a manual, hope you can use it,

Steps in CorelDraw(12 & 13):
->import the image
-> select the image
- -> select Bitmaps Menu
- -> select Mode
- -> select Black& white 1-Bit
->select conversion method [stucki] and vary the intensity

Steps in Photoshop:
->open the image
-> select image Menu
- -> select Mode
- -> select Grayscale
-> select image Menu
- -> select Mode
- ->select Bitmap
->select method [Diffusion Dither] and output 300 pixels/inch

[ArturoV]

I have been able to make decent black and white images(2-bit). But I would like to do grayscale images(8-bit) with more detail and better quality. Is it possible with the kind of Software I am using( lasercut 5.0) ? I get an error when I try to engrave a grayscale image(8-bit).
Thanks,

[Micheal Donnellan]

I have been able to make decent black and white images(2-bit). But I would like to do grayscale images(8-bit) with more detail and better quality. Is it possible with the kind of Software I am using( lasercut 5.0) ? I get an error when I try to engrave a grayscale image(8-bit).
Thanks,

anyone know if its possible.

[glintid]

anyone know if its possible.

All laser engravers are two bit, ie. bitmap devices similar to a fax when it comes to outputting non-vector images. The laser can be on or off at a specific power level. I think that the power level is varied by varying the pulse frequency too. so, we rely on software to convert multi-bit images to and convert them to 2 bit images. Some more expensive lasers have the ability to convert in the driver. Rabbit lasers (I have the 6090SE) requires the user to convert the image in a software program like Photoshop or Photograv or other image editing program. Typically, the image is converted to a half-tone made up of black dots of varying sizes and spaces to estimate the "grey scales" of the original image. This enables the laser to burn the image into the substrate.

The problem I had at the beginning is that I used a speed that was too great. The result was that the laser didn't have enough power, or didn't linger in one spot long enough to create the dark shadow areas of the image. The result being that the highlights and the mid tones of the images werefine but the areas that were supposed to be dark were mid tones or appeared solarized (reversed from their original tone). The solution is to adjust the speed and the power down until you get the shadow areas to read correctly. I found this by trial and error, it's not mentioned in any literature.

First, create a sample of grey shades from 5% to 95% and process it in your software and convert it to a 2 bit image. Then try varying power/speed combinations for each material used to get results that reproduce the sample as accurately as is practicable. You'll learn a lot from this exercise. I know I did and, I quickly found that the max speed quoted for the 6090SE is severely limited by the laser power.

This phenomenon I found is not always linear. In other words, the 5% to 80% shades are accurate but the 90% is not reproduced.

Experiment, experiment, experiment, that's all I can suggest and , record your results for future reference.

[ArturoV]

All laser engravers are two bit, ie. bitmap devices similar to a fax when it comes to outputting non-vector images. The laser can be on or off at a specific power level. I think that the power level is varied by varying the pulse frequency too. so, we rely on software to convert multi-bit images to and convert them to 2 bit images. Some more expensive lasers have the ability to convert in the driver. Rabbit lasers (I have the 6090SE) requires the user to convert the image in a software program like Photoshop or Photograv or other image editing program. Typically, the image is converted to a half-tone made up of black dots of varying sizes and spaces to estimate the "grey scales" of the original image. This enables the laser to burn the image into the substrate.

The problem I had at the beginning is that I used a speed that was too great. The result was that the laser didn't have enough power, or didn't linger in one spot long enough to create the dark shadow areas of the image. The result being that the highlights and the mid tones of the images werefine but the areas that were supposed to be dark were mid tones or appeared solarized (reversed from their original tone). The solution is to adjust the speed and the power down until you get the shadow areas to read correctly. I found this by trial and error, it's not mentioned in any literature.

First, create a sample of grey shades from 5% to 95% and process it in your software and convert it to a 2 bit image. Then try varying power/speed combinations for each material used to get results that reproduce the sample as accurately as is practicable. You'll learn a lot from this exercise. I know I did and, I quickly found that the max speed quoted for the 6090SE is severely limited by the laser power.

This phenomenon I found is not always linear. In other words, the 5% to 80% shades are accurate but the 90% is not reproduced.

Experiment, experiment, experiment, that's all I can suggest and , record your results for future reference.

That's what I figured. Try and error. Sometimes the only way to learn.
Ive done a couple of test now and I still cant figure out what the "scan gap" and "expand scale" boxes do? It would of been nice if somewhere in their stupid manual it explained the differences.

Anyways, Thanks for your advice!

[SkipW]

I think the scan gap is the distance between passes, or resolution. The higher the number, the greater distance between passes of the beam. It should probably be named "span gap".

Hope that made sense.

SW

[ArturoV]

I think the scan gap is the distance between passes, or resolution. The higher the number, the greater distance between passes of the beam. It should probably be named "span gap".

Hope that made sense.

SW

Does that mean the higher the number the lower the resolution is? Any idea what "expand scale" do?

thanks,

[SkipW]

Yes, the higher the number, the lower the resolution. (why didn't I say that?)

I don't have a clue as to what the expand scale does, sorry.

Skip

[glintid]

The scan gap is the distance the laser moves vertically (the Y axis) between passes. I think the Rabbit laser software expresses the distance as a fraction of a millimeter, ie. 0.1 is 1/10 mm etc. Because I am used to resolution expressed as standard numbers DPI (dots per inch), I converted mine and keep a chart near my computer. For example 300dpi is 300/25.4 dp mm which equals 11.811 dpmm. To convert it to distance between dots (passes) in mm you invert the number. So 1/11.811 = a scan gap of 0.084mm. I did this conversion for all the common usable resolutions which are 600, 500, 300, 250, 200, 150, 100, 75, 50, 40. Easier for me to remember than .084. When engraving photos, you want to use a scan frequency that is a multiple of the dot screen applied to the photo to convert it to a 2 bit .bmp file. This avoids a moire which is interference which is resultant when two lined patterns are superimposed and are out of phase. Like placing two pieces of screen material together at a slight angle.

If that seems simple, hold on to your hat. There is another variable affected by Scan Gap, power. It's actually logical. The laser spot on any material is not a crisp circle. The burn microscopically varies from material to material. It's similar to the pattern of a flashlight on the wall with an intense centre fading out to the edges. When engraving an image made of dots, the resolution is maintained by definition between the "black" zones and the unburned "white" zones. Some marerials .are inverted.

Each material is different. When the scan gap is close, the edges overlap which doubles the power at that point on the material. As the centre spots get closer, as you can imagine, the effect can be quite a dramatic increase in power. This sound efficient but in reality negatively impacts the image resolution, tending to blur it. So dependng on the burn rate of the material, you may have to increase the scan gap to get the optimum resolution. Wood for example requires a much wider scan gap than anodized aluminum.

Some brittle materials like glass, granite and marble don't burn but tend to microscopically fracture from the heat of the laser. (I think marble and granite fracture, open to correction). Anyway, if the scan gap is too close and the laser overlaps too much, the glass heats up and fractures through the area between dots resulting in a blurred, low res image. Some acrylic too tends to melt the whole surface when the dots are dense in the shadow areas and you loose resolution completely in the shadows resulting in a throw away.

These are just a few things I have learned by myself with trial and error and reading some scientific stuff on lasers and how they interact with materials. From this one realizes that laser focus and optics can make a huge difference. I have been thinking of getting an optically better (more expensive) lens for my laser to see if this in fact makes a difference to the resultant dot pattern. By the way, I experiment on plain, cheap brown card for the basic settings. It engraves quickly and holds a photographic image quite well.

Anyone suggest a source in Canada (or the US) for the lenses?

[MacGyver]

I've searched a bit, but haven't come across anything vastly cheaper for optics. You can always go with the ol' standby of Edmunds, but also consider using Thor Labs... they're optics seem reasonably priced (comparatively speaking, of course).

[SkipW]

The scan gap is the distance the laser moves vertically (the Y axis) between passes. I think the Rabbit laser software expresses the distance as a fraction of a millimeter, ie. 0.1 is 1/10 mm etc. Because I am used to resolution expressed as standard numbers DPI (dots per inch), I converted mine and keep a chart near my computer. For example 300dpi is 300/25.4 dp mm which equals 11.811 dpmm. To convert it to distance between dots (passes) in mm you invert the number. So 1/11.811 = a scan gap of 0.084mm. I did this conversion for all the common usable resolutions which are 600, 500, 300, 250, 200, 150, 100, 75, 50, 40. Easier for me to remember than .084. When engraving photos, you want to use a scan frequency that is a multiple of the dot screen applied to the photo to convert it to a 2 bit .bmp file. This avoids a moire which is interference which is resultant when two lined patterns are superimposed and are out of phase. Like placing two pieces of screen material together at a slight angle.

If that seems simple, hold on to your hat. There is another variable affected by Scan Gap, power. It's actually logical. The laser spot on any material is not a crisp circle. The burn microscopically varies from material to material. It's similar to the pattern of a flashlight on the wall with an intense centre fading out to the edges. When engraving an image made of dots, the resolution is maintained by definition between the "black" zones and the unburned "white" zones. Some marerials .are inverted.

Each material is different. When the scan gap is close, the edges overlap which doubles the power at that point on the material. As the centre spots get closer, as you can imagine, the effect can be quite a dramatic increase in power. This sound efficient but in reality negatively impacts the image resolution, tending to blur it. So dependng on the burn rate of the material, you may have to increase the scan gap to get the optimum resolution. Wood for example requires a much wider scan gap than anodized aluminum.

Some brittle materials like glass, granite and marble don't burn but tend to microscopically fracture from the heat of the laser. (I think marble and granite fracture, open to correction). Anyway, if the scan gap is too close and the laser overlaps too much, the glass heats up and fractures through the area between dots resulting in a blurred, low res image. Some acrylic too tends to melt the whole surface when the dots are dense in the shadow areas and you loose resolution completely in the shadows resulting in a throw away.

These are just a few things I have learned by myself with trial and error and reading some scientific stuff on lasers and how they interact with materials. From this one realizes that laser focus and optics can make a huge difference. I have been thinking of getting an optically better (more expensive) lens for my laser to see if this in fact makes a difference to the resultant dot pattern. By the way, I experiment on plain, cheap brown card for the basic settings. It engraves quickly and holds a photographic image quite well.

Anyone suggest a source in Canada (or the US) for the lenses?

glintid you are the man !!! Thanks for that awesome explanation and for the formula for converting scan gap into resolution. You've saved me many hours of work.

Skip

[glintid]

glintid you are the man !!! Thanks for that awesome explanation and for the formula for converting scan gap into resolution. You've saved me many hours of work.

Skip

Hey no problem Skip, I was asking the same questions not so long ago.