Need Help!- Engraving Problem

[g1r9a6d8y]

Hi, been studying this forum for the last couple of weeks and everyone seems very helpful.... anyway to the problem

I have a DC-K40III machine running NewlyDraw 1.5 software, i've had some success engraving and cutting different materials but sometimes have a problem with the head movement in both X and Y. On some bmp files especially with lots of detail the head will move erratically all over the cutting area and also sometimes stalls and sticks in one position with the laser light still active and burns a hole through the material. I use CorelDraw to convert jpg images to B&w(1 bit) for the raster engrave. If i import the original jpg image and raster engrave that its fine but there is no shading detail so waste of material really.

Could this be a data transfer issue ?(I have replaced the original parallel cable)

Controller, driver or stepper motor issue or maybe a mechanical issue ?

Any help would be greatly appreciated, thanks

[Pierke]

Hello,

try the same file again with a lower speed.
I think that the speed is to high for your stepper motors.

Pierke

[zax15uk]

It could be caused by a software problem due to the scanning.

When you convert the file are you dithering it, and generating a file of the correct size?

For example, if you are going to output it as 6" x 4" with a scan gap of 0.10mm then the image should be 1524 pixels by 1016 pixels.

Another possible cause is you are running the machine too fast, 12cm/s is probably the maximum you should run.

Does it work ok on big vector jobs?

Zax.

[g1r9a6d8y]

Originally Posted by zax15uk It could be caused by a software problem due to the scanning. When you convert the file are you dithering it, and generating a file of the correct size? For example, if you are going to output it as 6" x 4" with a scan gap of 0.10mm then the image should be 1524 pixels by 1016 pixels. Another possible cause is you are running the machine too fast, 12cm/s is probably the maximum you should run. Does it work ok on big vector jobs? Zax.

Hi Zax, when converting the image from jpg to bmp i resample the image to make it the size i want and then select a dpi of 300 for horizontal and vertical, either increase or decrease the contrast and brightness to make it look a bit washed out, then turn it to B&W with a jarvis conversion method then export it, When the export window comes up everything is as it should be but its still exporting as RGB 24, should i change this to B&W and tick the dither box or just export as default and see what happens ?

[g1r9a6d8y]

Originally Posted by Pierke Hello, try the same file again with a lower speed. I think that the speed is to high for your stepper motors. Pierke

Thanks for the reply but i have tried different speeds, both faster and slower and i have also changed the direction it engraves too, from left to right with small steps on the Y axis downwards and up to down with small steps across the X axis (hope you understand what i mean). Really want to get this machine working properly as its my first even if it means changing boards

[zax15uk]

Yes you want to save as B&W, no need to dither as you are already doing it with the Jarvis conversion.

Why are you using 300dpi? The laser can do 127 (0.2mm), 254 (0.1mm), 508 (0.05mm) etc.

25.4 / Scan Gap = DPI

I would start at 127 dpi for most materials, although some may look better at 254 dpi.

The flow you should follow is: first set the image size correct THEN dither, if you re-scale after dithering you destroy the file. Save without any further conversion, so the final image size should match the pixels per inch the laser is configured for.

If you want to send me a bmp file to check, PM me and I will give you my email address.

The laser should be scanning in the X-axis direction (moving the head) and stepping each line in the Y-axis (moving the beam). This allows the fast movement and acceleration with the lower mass.

Zax.

[g1r9a6d8y]

Hi Zax, thanks for the advice about SCAN GAP, I tried an image with a gap of 0.2 and it engraved all the image but without any detail..... I then lowered the gap down gradually and tried other engravings using the same image, at 0.15 still no detail so i lowered it again to 0.125 and this is where the head would start moving erratically again. I done 2 engravings of the same image and gap settings to see where on the image it starts messing up and on 2 seperate engravings it was always in the same place ?????

Now i am really confused

[zax15uk]

It sounds like a memory or buffer problem, probably made worse due to the conversion from pixels to laser.

I would create the image correctly at 203dpi (scan gap 0.125) and test it.

Zax.

[adayofjoy]

Originally Posted by zax15uk It sounds like a memory or buffer problem, probably made worse due to the conversion from pixels to laser. I would create the image correctly at 203dpi (scan gap 0.125) and test it. Zax.

is scan gap and line gap the same thing?
my settings are scan speed, cut speed, scan delay, cut delay, and line gap

[g1r9a6d8y]

Originally Posted by zax15uk It sounds like a memory or buffer problem, probably made worse due to the conversion from pixels to laser. I would create the image correctly at 203dpi (scan gap 0.125) and test it. Zax.

Cheers Zax, i'll try that, i thought that NewlyDraw would recognise the dpi automatically and change settings accordingly, i am beginning to hate this software lol

[g1r9a6d8y]

Originally Posted by adayofjoy is scan gap and line gap the same thing? my settings are scan speed, cut speed, scan delay, cut delay, and line gap

I hope what you are saying is correct, my software doesn't say scan gap either so i am presuming line gap is the same thing and thats what i am changing

[zax15uk]

Originally Posted by adayofjoy is scan gap and line gap the same thing?

Yes.

In ND1 it is Scan Gap, ND1.5 it changed to Line Gap but they're the same.

Zax.