View Full Version : vector engraving problem, starts with a gradient?

Linda Smith Alabama
05-18-2010, 10:37 AM
I recently got a 60 watt Chinese-made laser engraver. It vector cuts just fine and raster engraves fine, but when engraving vectors or text it sort of "fades in" on the first few rows, like there is some kind of gradient setting along the bottom. This happens in Coreldraw 12 and in Lasercut 5.1. It doesn't show up on the screen and I can't find any settings that would do that. I even tried exporting .ai from Coreldraw and importing into Lasercut and it does the same thing. Any idea what would be causing this?

Linda Smith Alabama
05-18-2010, 11:01 AM
I'll try to attach an example with text. This is the bottom line of text, there are several lines above it that engraved perfectly. I've reran the job over the same area and it does this every time in the exact same spot.

Linda Smith Alabama
05-18-2010, 11:11 AM
This is the bottom of a vector engraved logo on black & white marble. I went over this 5 times trying to get it to fill in the darker area. It starts normal, fades out for a few rows, then the rest of the logo is perfect. I'm at a loss...

Gary Hair
05-18-2010, 11:32 AM
It could be out of alignment. Try running the job from top to bottom and see what happens. If it's the same then I would suspect alignment.


Dee Gallo
05-18-2010, 12:33 PM
Did you try moving the work to another spot on the bed? Is your table level? Did you use manual focus or auto focus? Have you ever had another job fade in the same position?

Rodne Gold
05-18-2010, 12:55 PM
Looks like the tube is losing power or there is some bug in the software/firmware - see if there are upgraded drivers for it .
In the meantime - if it rasters ok , convert the CDR to a raster file and engrave that. Not the ideal solution , but it will tide you over .

Linda Smith Alabama
05-18-2010, 1:23 PM
Thanks for the suggestions.

The tube is definitely putting out less power in that area, and the same image engraves the same way regardless of where it is started on the bed. We just checked mirror alignment, and checked to make sure the table is level with the head. I'll do some more testing and try it from top-down to see if it makes a difference. I'm wondering if it is the software driver. I haven't had any luck finding an updated driver (it's a Chinese MPC03 card.) It's so strange, it cuts vectors fine and engraves raster fine.

Linda Smith Alabama
05-18-2010, 7:55 PM
Running from top to bottom does indeed make it fade in at the top instead of the bottom; it is fading in on whichever side it starts on. Does that sound like an alignment problem or software settings?

Gary Hair
05-18-2010, 8:00 PM
Since it does it at the start of the engraving, I'm thinking the tube is "warming up" gradually and that's causing the gradient. It could be a bad tube, power supply, a whole host of things "could" cause this problem. I would talk to the manufacturer and see what they say. That may be hard to do since they are in China, but that's probably the best resource you'll have for that machine.


Dee Gallo
05-18-2010, 8:18 PM
So, until you fix this problem, could you make a line or shape that the laser can warm up on but not be on the actual workpiece? If the workpiece is too big for that, could you place a piece of metal over the area to block it?

Just a thought. cheers, dee

Linda Smith Alabama
05-18-2010, 8:19 PM
Thanks for the comments, I appreciate your feedback. I've suspected that myself, but I'm not so sure because if I change from engrave to cut, the laser is hot and cutting through instantly. The problem is only when it's set to engrave.

Andrea Weissenseel
05-19-2010, 3:22 AM
I would try Dee's suggestion, just place a scrap piece in front of the actual engraving and raster a few lines. On the pictures it looks like the area is always the same size, so you know how large your "warm up area" needs to be


Rodne Gold
05-19-2010, 3:50 AM
If it engraves raster based stuff without an issue - then its not going to be a warm up problem IMHO

Hannu Rinne
05-19-2010, 4:56 AM
My other laser is also Chinese made 60W, with Lasercut 5.1 and I have exactly the same problem with it, as you can see on the attached photo !
First few rows burns compairing to rest of the engraved area - and this
is only engraving mode problem, cutting goes fine. I've tested to engrave
from bottom to the top and from the top to bottom - same situation...
Also does not make any difference with the location on the working area.
I've asked about the reason from the dealer, but so far haven't got any answer for this. I haven't had enough time to try to find the reason myself but it must be something to do with the driver. Maybe there is possible to
increase the starting speed - only what I can imagine is that the reason
causes from the slow starting speed vs. power because after few rows the engraving goes pretty smoothly...

- Hannu

Linda Smith Alabama
05-19-2010, 12:50 PM
Thank you Dee, that's a very good idea to get good results until it's fixed.

Hannu, thank you so much for posting! The fact that we both have the same issue gives me hope that it is a software problem and not a bad laser tube. :)

I played around with the engrave settings a little... changing "acc len" made a slight difference in the beginning of text engraving. Problem is I have no clue what all those settings mean, or what to change them to. Would you mind comparing settings? Maybe together we can figure this out.

I found a language.ini file for the MPC03 here with very different engrave settings than my language.ini has: http://www.scottware.net/Lasers/DriverDisk/MPC03/MPC03LV3030/MPC03-LV% (I think that is an older driver but I'm going to try it anyway.)

Hannu Rinne
05-19-2010, 5:04 PM
Hello Linda,

Of course we can compare those settings ! Honestly saying I can't remember which card I have, MPC03 or MPC6515, but I'll check it and the driver. I think that you don't have to worry about your tube - it must be some software problem ( but because I'm not any "laser engineer" I can't be 100% sure :) ). If you like, you can send me some test file to my address - harinne@suomi24.fi - with the settings you've used on it (power,speed,scangap) and I'll test it with my machine and send you the results. I can also take printscreens from the Lasercut machine settings and send those to you, so you can check them. I'll also ask about this problem from the manufacturer and if they answer, I'll let you know ! I'm sorry if my answers to you delays, reason is the time difference and my main work ( 24h is too short :) ) but I'll try to make answer as soon as I can.

Best regards
- Hannu

Linda Smith Alabama
05-19-2010, 7:06 PM
Thank you so much Hannu, I really appreciate your help! I will send you an email later. :)

I discovered today that this is not limited to engraving. If I turn the power down and vector cut a circle the ends don't quite meet. Also cutting a straight line at 100% power is longer than cutting the same line at 50%. The beginning is very slightly "fading in" but also the end is "fading out" just not as noticeable as the beginning. So now I'm totally baffled...

Hannu Rinne
05-20-2010, 1:56 AM

When you do vector cuttings, how do you export your files to Lasercut ?
You could make a test > draw a circle and save it in ai. and plt. modes.
Then open those separately in Lasercut ( with import command ) and cut
with the same settings and check if there is any difference between
these modes. Do this also with the lines... I will test with my machine
how those lines goes with those power settings you mentioned.

Best regards
- Hannu

Hannu Rinne
05-20-2010, 6:10 AM
I just got a reply from China and they think that this engraving problem is from the warming of the laser ( as Gary, Dee and Andrea mentioned ). They propose to make a little square or circle (~10mm) beside the actual engraving and start the engraving from this point so that the laser warms up enough and after this start immediately engrave the actual work...
Might be a little frustrating if you have to do this with every job :( But still it is worth of trying... I'll test this with two piece of same material so that I engrave that small circle first to the other piece and then move straight to the actual... For the line cutting problem they didn't answer yet but as soon as I hear, I'll let you know !

- Hannu

Linda Smith Alabama
05-20-2010, 2:09 PM
Hannu, thank you so much for your help! I am certain this is a software issue. This morning I upgraded to Laser Cut 5.3 and the problem appears to be fixed! There might be just a slight difference in the power at the beginning, but nowhere near as bad as it was. Since you have a similar problem with Laser Cut 5.1, maybe upgrading would helps yours too. I downloaded it from here: http://www.scottware.net/Lasers/DriverDisk/english-6090SE/

This install works with the white dongle. It assumes you have MPC6515 controller. Since I have MPC03 I just had to go into machine options and change the controller after installation.

Hannu Rinne
05-21-2010, 2:15 AM
Hi Linda,

Great to hear your problem is solved !! And thank's very much for the upgrade link - I'll test it and see how it works in my machine. And yes, as I checked my card, it is MPC6515. I also got the answer from China meaning that line cutting problem. They answered as follow;

"Thanks for your cooperation test and also for the attached photo explanation, that is almost same as our understanding of your problem, about the short of the lines with lower power, that does not mean the line is short, the fact is the unstable output of the laser light, as you can understand, with different laser power, the laser strength is not same, as the laser is not very stable at the beginning, and with a lower power, so the cutting at the beginning is not clear or visible, then, in the cutting result, it seems with different power, the lines cut seems short, actually, that is just the cutting at the beginning not visible or clear enough. Also, under this kind of situation, you can also have a check the laser light way, and if necessary, clean the mirrors and lens. that is also a good way to improve the working result. Thanks and wish the above explanation is understandable and useful for you."

Anyway, I feel that your help to me was much more better than mine to you :) I wish you good "laserings" !

Best regards,
- Hannu

Rodne Gold
05-21-2010, 2:20 AM
Wow , that "chingrish" reply is kinda garbled - what would REALLY go a long way to making these chinese lasers a lot more acceptable worldwide is if they had to hire a really good translator.

Hannu Rinne
05-21-2010, 2:42 AM
Chingrish :):):) - I can't give any comment because mine is Fingrish :):)