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Jeff Wilkins
01-17-2013, 11:11 AM
Quick question, I want to engrave the letters of this logo, the way they look on the screen. The problem is that they are filled black with a black line around them. The line thickness is so small that my laser treats it as a vector. How can I merge it so it treats it as one filled object and not a fill with a thin line around it? Thanks for your help. I have attached a v10 version.

Bobby Etchison
01-17-2013, 11:37 AM
Since the outline is so thin, why not just remove it?

Bill Overturf
01-17-2013, 11:57 AM
2 options 1 make the outline thicker or 2 select the outline click on arrange and at the bottom of the list is an option to convert outline to object. Hope that helps

Steven Cox
01-17-2013, 8:31 PM
Go with Bill's suggestion convert the outline to an object the only thing I'd add is do it to each letter then weld the outline back to the letter, its a bit of work but only takes a few seconds for each one. When converting to outline if it goes wrong try changing the corner type to something else in the outline settings box.

Richard Rumancik
01-17-2013, 9:22 PM
Jeff, what material are you engraving this on, what lens are you using, and what dpi were you planning to use? You'd probably have to be at 500 dpi or above to reproduce the detail.

This is a pretty challenging logo as the characters and detail are very fine. Personally I'd probably convert the whole thing to a bitmap at 500 or 600 dpi and then plot on the laser at the same resolution. On one project I had to use 1000 dpi for a detailed logo like this; this is viable only if the added laser time is tolerable. (That was done with a 1.5" lens.)

Chuck Stone
01-17-2013, 9:43 PM
Some of that detail might be beyond the resolution of the laser.

EDIT .. sorry, just saw that Richard was addressing that too.

Even using 500 or 1000 dpi, that won't resolve the detail because the
beam size is probably in the .005" or .004" range. (200-250 dpi)
a 1.5" lens would give sharper detail, but might max out at 300-350

Michael Hunter
01-18-2013, 11:33 AM
Having done similarly sized and detailed logos on close-grained hardwood, I think the others are being a mite pessimistic.

It is a case of trying it out and then making adjustments until you get an acceptable result - which may take up some time.
It depends on the customer and order value as to whether the perseverance will be worthwhile

At this scale you will need to allow for the relatively large "dot size" of the laser, by making the black details smaller and/or adding white outlines.
600 dpi will probably be OK for wood - certainly try this to start with.
For Rowmark, I would probably go straight to 1200 dpi.

Chuck Stone
01-18-2013, 12:42 PM
Having done similarly sized and detailed logos on close-grained hardwood, I think the others are being a mite pessimistic.

It is a case of trying it out and then making adjustments until you get an acceptable result - which may take up some time.
It depends on the customer and order value as to whether the perseverance will be worthwhile

At this scale you will need to allow for the relatively large "dot size" of the laser, by making the black details smaller and/or adding white outlines.
600 dpi will probably be OK for wood - certainly try this to start with.
For Rowmark, I would probably go straight to 1200 dpi.

Easy enough to find out:
Find the beam size for your laser/lens combination. Zoom in on a high detail section of the logo
and draw a circle that size. That represents your laser beam. If it is larger than your detail, it
won't work.

Laser manufacturers claim high dpi, but they use it differently than other industries do.
DPI used to mean a reciprocal of the size of the dot. 200 dpi meant that each dot was
1/200" . 400 dpi mean each dot was 1/400" in size and so on. Smaller dots mean a
higher ability to resolve detail. But you can't vary the size of the dot except to change
lenses or use it in/out of focus.

When laser manufacturers use the term DPI, it is more like 'stepover'. 500 dpi means that
the lens will move 1/500", not that the laser beam will be 1/500"

Most of our lasers run in the 200-300 dpi range. Which is still pretty decent. Most consumer
printers max out around 280-300 dpi, despite larger claims. and some say that people with
20/20 vision can't resolve over 450 dpi at normal viewing distances anyway.

So .. while I'm not saying there is no reason to run at 500 or 1000 dpi, I am saying that
resolving details smaller than the size of your beam shouldn't be one of them.

Michael Hunter
01-18-2013, 9:03 PM
Chuck-

Agree with all you said, but practical experience shows that higher dpi can help improve small details.

This is because (with an Epilog and probably other makes too) the image is quantised to the dpi chosen. If a detail is "off grid", then the laser isn't fired.
To get more detail, you need a finer grid.

Its easy to demonstrate this - just engrave a fairly complex design at 75 dpi (or whatever the lowest is on your machine) and see how much gets left out.

Chuck Stone
01-18-2013, 9:39 PM
Well .. 75dpi is below newspaper resolution, which is pretty low!
But I know what you're saying.

As I mentioned,there are reasons to use a higher DPI. Certainly it can
gives you a cleaner image. But it won't give you resolution beyond the
size of your beam. In this case, he has areas that are 0.001" in size.
The laser will not reproduce those, the beam is just too wide. Even
setting the resolution at 1000dpi (or higher.. doesn't matter) the size
of the beam isn't software controlled. The lens determines the size.

.. just for kicks, I zoomed in on part of the detail and drew a red dot
the same size as a typical beam from a 2" lens.

Michael Hunter
01-19-2013, 9:18 AM
Here's a sketch to show roughly what is going on.

I don't know the exact details of how the driver decides whether or not the laser is fired at a particular position, but from my observations and experiments, this is not too far away from reality.

When engraving small logos, there will often be parts which either don't engrave or - if they do - come out much too thick.
In these cases an artistic decision is required (leave in or take out) in order to make the logo as appear near as possible to the original.
Fortunately, the eye is easily deceived and recognisable things like lettering or stars will usually be seen as being good, even if they are rubbish under a magnifying glass.

David Rust
01-19-2013, 11:21 AM
Here's another way to look at the dot spacing and overlap that Chuck and Michael are talking about...

251673

Mike Null
01-19-2013, 12:30 PM
Here is a dpi example as provided by Epilog in their users manual.

Richard Rumancik
01-19-2013, 4:07 PM
Chuck, you are correct that the detail in the area that you magnified will not reproduce really well. The claw features will close up and the white detail in the wings will disappear. Having said that - it really won't matter for what is being done here. The end product is going to be viewed at a 12" + distance and the eagle will look just fine.

It is true that you can't accurately reproduce a .001" wide line - the laser will either burn the pixel (.005" spot) or else leave it out, depending on how the feature aligns with the .001" grid when converted to a bitmap (which will be done either manually or by the laser system when plotted).

Michael, that's a good sketch you made. It helps visualize what will happen to the edges at higher resolution.

I'm guessing that if a pixel grid is 50% or more filled with black when the vector is mapped to it, the laser will plot a dot. Maybe there are more sophisticated conversion schemes.

All edges will be smoother at higher resolution because the laser is stepping .001" (say) at 1000 dpi. All text characters will look "bolder" than the original image. Although some detail will be lost, and all object edges will tend to "grow" (due to "dot gain" as a result of a spot size being greater than the pixel size), it can still be made to look good enough for the purpose.

If you convert the image to b/w bitmap at the desired plotting resolution (600-1200 dpi) the stars may not look good when zoomed in, but I am pretty sure (as Michael stated) that they will be recognizable as stars and will look fine to the viewer.

It might take a few tweaks depending on how fussy one is (and if the job merits it) but this image is laserable in my opinion.

This discussion has evolved a lot from what Jeff asked - my suggestion was to convert the logo to bitmap before plotting (which would capture both the outline and the shape). Jeff -are you there? What did you try? Let's get's some practical input on this discussion rather than just theory.

matthew knott
01-19-2013, 6:57 PM
Hows this, you can turn the outline of as its a solid object and does not need the outline to create the effect off the logo! Out of interest is there a quick way to get from the original to this, ie just a few clicks on corel?


Having trouble with the attachment, cant delete the top image, its the corel draw file im talking about