Deeper Engraving on Border when Rastering

[Chris Thomason]

I have had a Rayfine 9060 100w for a couple months and have been very pleased with it so far. This forum has been a great resource for me as I begin to learn how to use the machine.

I was raster engraving some wood yesterday and got an unexpected result. The left and right borders around what I want to engrave are quite a bit deeper than the middle. It looks like the laser power is starting too high and leveling off after a very short amount of time. Has anyone encountered this before? If so is there a setting to mitigate this that I am missing?

Sorry for the low quality pics couldn't get the phone to focus.

[Mike Null]

Chris

Welcome to SMC.

Does the font have an outline? If so delete it and try your job.

[Chris Thomason]

That was my fist though as well but I converted it to an all black bmp file and got the same results.

[Mike Null]

Do you have the ability to view your file in wireframe view. If so you can see whether the outline is still there even though it shouldn't be.

[Chris Thomason]

I am not familiar with wireframe view. Is this an option in RDWorks or another program? Thanks for your help.

[Mike Null]

It is an option in CorelDraw. I have no knowledge of RD Works.

[Matt McCoy]

You might try rotating the grain 90 degrees to troubleshoot the material first.

[Kev Williams]

Looks to me like it ran a raster pass then followed up with a vector outline pass- If you have any type of 'raster + vector' checked in the engraving setup, this will happen. You can't remove the outlines, aka the toolpath, from a vector file because that's what vector art is, toolpath lines for the machine to follow or reference from. Bitmaps don't have lines, only colors, which are converted to halftone dots. If you converted to a bitmap file, then you would've had to have engraved it in 'image' or halftone mode. Glass lasers have on/off issues on the edges, but usually it's a fade in/fade out thing and not too noticeable most of the time. Your outlines aren't fading, they're very 'specific'. Different to be sure!

[Chris Thomason]

Thanks for the suggestions. I'll try different material and engraving orientations tonight. If I do one direction scanning I may be able to find out if the extra power is from when the laser turns on or off.

I had the min and max power both set at 30 could a range of power help mitigate the issue?

I don't think it is a border issue with the text in the file, only the vertical lines have the extra border depth. The horizontal ones are correct.

It also is not doing raster then vector engraving. I notice the borders forming during the raster pass.

[Dave Sheldrake]

It's DC strike

When a DC tube fires it sends max current to the tube to initialise it, that causes a higher than normal blast of energy from the tube as the mark starts.

There is no way to stop it as it's the physics of a DC laser tube

[Chris Thomason]

I tried several more options and settings. The cause seems to be the laser power jumps up too high when starting to form the beam. I did a test with one direction engraving and only got the deep outline at the beginning of the cut.

This one was also with the grain perpendicular to the engraving.

[Chris Thomason]

Thanks Dave. Didn't see your response before. Appreciate the education. I will have to adjust power and speed to try to get a better looking result.