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Quality of Laser Engraving - Pulling my hair out!!!!

Posted: Wed Sep 06, 2017 1:03 am
by jwk87
Hi all,

We have a NC-1390 Laser Cutting Machine. which is a 80w machine. I am trying to engrave a scanned photo onto granite and it appears to lack detail in the engraving on the granite.

I have changed the settings many many times on the machine to attempt to get a good engrave but just cant seem to manage it.

This is the source file that we are using (file size we are using is a larger file size then what I have attached here).
couple.jpg
couple.jpg (48.66 KiB) Viewed 4413 times
We are using the software that has come with the machine from china it is RDWorksV8.

The settings I have used that has created our best engrave thus far is.
scan settings.jpg
scan settings.jpg (59.13 KiB) Viewed 4413 times
I have it set as x-unilateralism as it only does one engrave then returns and engraves again, instead of engraving and then engraving on return seems to be a better quality engrave.

The laser is set at 5mm.

This is the image that we put into the machine - it is a gray scale and has been inverted and is in a Bitmap format.
couple_nobg.jpg
couple_nobg.jpg (32.76 KiB) Viewed 4413 times
This is our best engrave so far on black granite but it does not show enough detail and seems to be flat in quality and not a true scan copy of the image.
image2.JPG
image2.JPG (122.36 KiB) Viewed 4413 times
I really dont know where to go with this now to make a better engrave. I have tried by just loading the source file with the background and still that lacks detail.

Any ideas and tips would really be helpful, secondly what does the second power setting actually do and should that be at a different setting to power setting 1.

I look forward to any replies.

Thanks

Jason

Re: Quality of Laser Engraving - Pulling my hair out!!!!

Posted: Wed Sep 06, 2017 7:25 am
by LINUS
The picture no setting,a leading cause of bad engrave effect.And laser soft setting is no good at engrave.
You don't need set second power.
Let me recommend a few laser engrave tutorial
https://www.youtube.com/watch?v=6rYtFaRngAk
https://www.youtube.com/watch?v=XFy39AZJvL4

Re: Quality of Laser Engraving - Pulling my hair out!!!!

Posted: Wed Sep 06, 2017 11:22 pm
by jwk87
Thanks, I had seen the first youtube clip before, but not the longer second one.

I dont really understand when you say
The picture no setting,a leading cause of bad engrave effect.And laser soft setting is no good at engrave.
Thanks

Jason

Re: Quality of Laser Engraving - Pulling my hair out!!!!

Posted: Fri Sep 08, 2017 11:26 am
by terry corder
HI,I tried to attach a bitmap of your photo but not allowed to. If you can PM me perhaps I can get it to you that way,

Re: Quality of Laser Engraving - Pulling my hair out!!!!

Posted: Sat Sep 09, 2017 2:41 pm
by closeracing
Try this. Invert color/click set output resolution/set resolution to 300/check Dither/set frequency to 70/check dot graphic/apply to source

Re: Quality of Laser Engraving - Pulling my hair out!!!!

Posted: Thu Sep 14, 2017 4:36 am
by jwk87
Ok,

Thanks for the responses, dont really understand the difference between net and dot graphics.

Having watched those clips from the previous post, I understand the resolution and the net graphic dither and making the circles more rounded and closer together.

I attempted another photo of the same couple on the wedding day. The picture is a black and white image. It is a BMP file loaded into RD Works.
NAPOLI.jpg
NAPOLI.jpg (428.18 KiB) Viewed 3885 times
My BMP settings are set as follows
1500 resolution 70 net graphic.jpg
1500 resolution 70 net graphic.jpg (301.57 KiB) Viewed 3885 times
My Burn Settings are set as follows
engraving settings.jpg
engraving settings.jpg (58.21 KiB) Viewed 3885 times
This is the end result I get.
output.JPG
output.JPG (480.39 KiB) Viewed 3885 times
If I change the power to less than 12 it wont engrave, if I put it up higher say over 20 or so it just gives a great white blob on the tile.

The image has engraved ok, but it is too light and very dull. This would be suitable if it would engrave a lot darker so I can actually see it and basically make it brighter.

Any suggestions??

Thanks

Jason

Re: Quality of Laser Engraving - Pulling my hair out!!!!

Posted: Thu Oct 12, 2017 12:19 pm
by closeracing
I have a 60w laser and for most images starting at 20 is too high. RDworks doesn't have the greatest dithering process, but if you read the manual it says dot graphic dithering is for higher quality. With net graphic you can see a pattern in the engraving.
You would benefit a lot from a program like Corel to massage the images before sending them to RDworks.
I just looked at your settings again, try 300 dpi with the interval set to 0.0847, dot graphic and see if that makes the faces clearer. 1500 dpi on granite is way too high.