Vector issues and picture engraving on black tumbler

swb2120 · April 16, 2025, 12:50am

Cloudray 60W MOPA fiber w/ SL-1064-200-290 lens

I have a picture of a Rolex watch face that I have cut out and attempted to turn into a vector in AI and some other online sites to no avail. Because I couldn’t get the image to vector correctly I started to burn as an image. I watched both parts of the LE videos on engraving images but I couldn’t get the image to hold all of the features as I was using the adjust image function in LB. I have used both cylinder correction and a rotary to burn the image but still loose details in the photo as it burns the powder coating of to the SS. If there is something I am missing when conducting the image trace to create the vector or a step I am screwing up in burning an image I would appreciate any support. Thank you for your time.

Also if anyone can shed some additional insight on the cylinder correction and lens working area I would love to hear some additional information on laser distance, I’ve heard 2mm closer with the 200 lens to have the image burn on sides with same intensity as if the laser focus was at exact height for optimal engraving. I have switched to 420 lens and if gives you a bigger work area but still failing to engrave on sides as well as it does right on top if set at proper focus. Thank you again.

MikeyH · April 16, 2025, 1:14am

That looks like a 12mm+ drop from the center to the sides. getting a consistent burn that far around the mug would require the rotary.

My experience is with diodes, so what I say may not apply…
You show a scan angle of 45 degrees, but you should do the scanning with the Xaxis.

You do not say what your dot size is, so I do not know if 504 DPI is appropriate. I would lower this until I got unburned traces, then bump it back up a little. If you could lower it to say 318 DPI ,you would save a lot of burn time.

I seem to remember that a CO2 4" lens gives a big dot and a 2" one gives a small dot. @jkwilborn will correct me if I got this backwards.

jkwilborn · April 16, 2025, 7:58pm

@MikeyH is correct, the longer the lens the larger the spot and deeper the depth of focus (dof).

He’s also correct in that a scan angle other than 0/90 depending on the rotary position is the best option for the least amount of movement.

@MikeyH probably doesn’t know as he’s never had any reason, is that a galvo can position the X/Y orientation independent of what axes you’re using. As long as you’re scanning along the rotary axes, you should be OK.

These are common fiber lenses from Cloudray, you can also relate it to spot size. You can compute these as there are many on-line calculators.

I use the lens notation as a basis. In the chart they do no have a 290mm lens, so I’m not sure about which lens you actually are using.

There is usually an F number, such as F420mm that covers 300x300mm area.

Also notice that there is two F210mm with different coverage area, because of the change in scan angle.

I have four lenses, an F100mm (70x70mm coverage), F160mm, F254mm and an F420mm.

I’m not sure what you issue really is, I don’t see anything unexpected, maybe my old eyes just don’t see it. There are black, no color and mid range densities that have to be taken into account for this to lase well as an image.

All of these seem to be around areas of the mug that don’t change much in diameter.

Defocusing by how much depends on the lenses dof or it’s focal length. It makes your spot size larger. This may require more power.

I think the most suspect is your art work. This would be easy, clean and very fine if done with vectors. I think what you see are parts left over in your original art photo.

Did I help at all or was it just more confusing?

swb2120 · April 17, 2025, 12:04am

Mike and Jack,
Thank you both for taking the time to answer. Jack it has already helped in the understanding of DOF and how to calculate the engravable area. Mike the 12mm note you gave was spot on and already helped in the image burn. Jack the problem with the photo burn is the lose of details in the hour hand of the watch as the engrave goes deeper. I have attempted to make the image into a vector and it doesn’t retain its details and that’s why I’m using a photo. I am going to continue to burn with trial and error to find the right settings and hope to post an update soon. Thank you both again!