any idea why ......

[Graham Taylor]

........... on the simple grid attached, when I engrave it into aclear acrylic the horizontal lines are engraved thicker than the vertical lines even though I have used the same line for all?

It is like this on various power and speed settings and I have no idea why - hopefully it is something simple that someone can suggest and if so, be my guest to call me a muppet

grid 1.JPG

It is an RGB Black, 1.0 pt in weight
grid 1 settings.JPG

[Joe Pelonio]

I have had that happen when doing a bunch of grids on a softer material such as Rowmark. It has to do with the way the horizontal lines get marked all the way across smoothly, while the verticals get hit briefly as the beam passes by. There are two ways around this. For thin lines, use vector, much faster and very even lines. Just don't go too deep. The other is to make the vertical lines slightly thicker, that takes some trial and error to get right.

[Dave Sheldrake]

Linear Polarisation

[Mike Troncalli]

Could your laser head be set at a small angle. You wouldn't know it traveling along 1 axes, but you would going along the other.

[Doug Griffith]

Instead of engraving, I would vector at reduced power. The operation will be faster as well.

[Graham Taylor]

I will go with Joe's suggestion of making the lines slightly thicker.

I am using the following settings P-23, S-80, PPI 1000, Air Assist off so it is fairly low power.

I am a bit confused because I thought that creating a line using Corel as 1 pt black was a vector line - if this is wrong please be gentle with the abuse

[Mike Troncalli]

I will go with Joe's suggestion of making the lines slightly thicker.

I am using the following settings P-23, S-80, PPI 1000, Air Assist off so it is fairly low power.

I am a bit confused because I thought that creating a line using Corel as 1 pt black was a vector line - if this is wrong please be gentle with the abuse

Our software drivers might require different things, but mine requires the line in Corel to be set to hairline for vectoring

[Graham Taylor]

Our software drivers might require different things, but mine requires the line in Corel to be set to hairline for vectoring

Trotec its hairline for cutting

[Bert Kemp]

yes hairline for vector just lower power and speed it up so as not to cut thru, its called vector engraving

Trotec its hairline for cutting

[Graham Taylor]

yes hairline for vector just lower power and speed it up so as not to cut thru, its called vector engraving

Ahhhh, so what I thought/am doing is correct and I am not a muppet (on this occasion) after all

Thanks for your help guys

[Bert Kemp]

Graham
if your setting is 1 pt then no its not correct you want to set your lines to HAIRLINE then lower your power and increase your speed to cut your grid at a vewry shallow depth. all lines should be same thickness

Trotec its hairline for cutting

[Graham Taylor]

Graham
if your setting is 1 pt then no its not correct you want to set your lines to HAIRLINE then lower your power and increase your speed to cut your grid at a vewry shallow depth. all lines should be same thickness

hmmm, will try that tomorrow then - I have been in work for 12 hrs already and I am getting a bit confuseed and hungry so its time I left and ordered my Indian curry mmmmmmmmmmm, fat belly time soon

Thanks again

[Dave Sheldrake]

Linear Polarisation

In one direction the beam will be thinner than in the other depending on how aligned it is with the polarisation angle. It's the nature of lasers, circular polarisation with 1/4 Phase or 1/8 Phase is designed to prevent this on bigger machines.

[Kev Williams]

In working with fonts, 1 pt typically equals pretty close to .01", but Corel translates 1 pt as .014", so I'll assume your 1pt lines are supposed to be .014"...

That said -- another issue is the resolution you have set. At 500 lines per inch, the beam paths are .002" apart. That means 7 sweeps to cover exactly .014". However, the cut will actually be .014" plus with width of the beam spot. When running the vertical lines the laser must fire and stop within that .014". Simply because of the short time the laser has to do this, AND because even at 500 LPI there will be a speck of un-engraved space between the beam paths along the edges, the likely result is the width of the lines appearing a teeny bit smaller.

If you want the lines all the same, instead of drawing a single line and fattening it up to raster it, how about drawing .014" wide rectangles and weld them together. Give them hairline outlines, raster them, THEN follow that with a low-power vector pass. Every line should be, and appear identical...

[Lee DeRaud]

...I am not a muppet (on this occasion) after all

That clearly means something completely different in the UK than it does here.
(Although I did find one definition that I can't repeat here that loosely ties the two meanings together... )