Engrave off?

[Robert Silvers]

I keep on hearing how RF C02 is so much better than DC. I think we should have an engrave off - hopefully with US and Chinese machines.

Test 1:

Engrave 1mm high text in Arial. Type to engrave is "1mm tall Arial" Take close-up photo to show sharpness. Post machine, speed, and power. Substrate - painted metal or anodized aluminum.

Test 2:

Pick a common image to engrave, say a photograph with lots of grayscale, and see who can do best with what machine.

I looked around for a photo that has good exposure, a nice range of grays, and is a portrait. This is what I came up with:

http://www.washingtonpost.com/blogs/...2H16190604.jpg

If we do this, we would need a common substrate. Black anodized aluminum would be best, but that is rare and expensive.

I propose mirror tiles from Home Depot because a six pack is $10 as you can get sharp small dots on it:

http://www.homedepot.com/p/Erias-Hom...5#.UliL42RATHI

Lowes has them also.

Engrave the back 10 inches tall, and then take a photo with it lit from behind. It provides extreme contrast because it can block the light 100%, or let a lot through. Note that you will have to reverse the image left-right, and probably invert it to not get a negative image. This will have to be half-toned. Post machine, speed, power, and how you made the image file.

Anyone?

[Dan Hintz]

These kind of "throwdowns" have been cast from time to time, but they really serve no purpose other than to get people riled up. Save your energy.

If you really must, Steve (Scott) has posted some sweet detail in the past from his machines... usually with sub-mm fonts, if memory serves.

[Kev Williams]

Robert, before reading this thread, I just posted in your other thread, a couple of pictures of some sample engraving from my LS900, and asked if you wouldn't mind trying to duplicate the results! I'm not interested in this as a "my machine's better than yours" thing, it's simply because I need to know if your laser will engrave as well as mine, since I'm about THIS CLOSE to buying one! Because of the work I do I need a machine that will produce similar results to mine (or better will do too!)

<edit> thought I may as well post the pics here too!

DSC02537.JPGDSC02536 (Custom).jpg

[Scott Shepherd]

Kev, that's pretty darn good on the small scale. I'd also be interested to see if the Chinese machines are at that level of quality on things that small. I've not seen it myself, but I've seen numerous threads by Chinese laser owners that have said the detail on really small stuff isn't that great, so I'd love to see that example sample you posted from someone with some of the various Chinese machines.

[Robert Silvers]

I will refine my statement to:

You said in another thread that you would be hard pressed to tell the difference between fiber and C02 for marking aluminum, unless it was a 2 point font. It would be good to see what the difference is with the same mark.

[Scott Shepherd]

Here's a rough one from yesterday. This was the test piece so the speed/power wasn't quite right. Too slow so it's slightly blown out.

Cermark on brass : Font is .030" tall on the capital letters, if I recall correctly. The production pieces are sharper than this one, but it shows an example.

brass.jpg

[Robert Silvers]

I need the typeface and the units you used for size.

[Robert Silvers]

Nice wallet.

[Kev Williams]

Robert, font is just Arial regular, NOT bold, and the .12 high is 12 point, .01 high was 10 point, etc, the sizes in inches come to within .002" of the point size-

Scott, that's some nice engraving-- what lens you get that with? 2" on mine--

Oh yeah, settings-- 800 dpi both ways, 40% power and 30% speed I think it was--

[Robert Silvers]

There are 72 points to an inch.

So 12 points is 0.167 inches.

2.5 points is 0.035 inches.

Just type into google: "12 points in inches", and it will tell you.

I will print one tonight in points instead of inches so that it will match yours, as soon as my current run ends.

BTW, my software does a horrendous job at spacing characters. I just put this into the software, and it had too much space. I will try it in Illustrator and convert to DXF.

[Robert Silvers]

I made the engraving. It was useful as it helped me work out my work chain. This is the first time I tried to create a file in AI and import it. I can say that I was not able to import from the Mac version of AI either from AI, EPS, or DXF format even trying just about every option of using older versions of the file format and creating font outlines. I was able to save the file, load it into the PC version of AI, and the software could read those files.

I am photographing the result now.

[Kev Williams]

There's points, and then there's points-- all I know is Corel's points are nearly equal to .010". Below is a screenshot from Corel, the "XYZ" text is grouped, Corel shows actual text height is .199", and text point size is 20- It is what it is!

Regardless of that, I'm still very interested to see if you can get the same or close to the same quality of lettering with your machine! - it doesn't really matter on what material, anything handy-- I'll know if I like it when I see it--

I translated the corel job into actual size in MM, from top to bottom the MM sizes are:
.12 = 3.32mm
.10 = 2.76mm
.08 = 2.21mm
.06 = 1.66mm
.05 = 1.38mm
.04 = 1.11mm
.03 = 0.83mm
.025 = 0.65mm

points.jpg

[Robert Silvers]

[Rodne Gold]

When I got my shenhuis , I compared them to my GCC spirts and explorers , which can do fine text real well
My 60w cheapy tubed shenhui did as well as any of my other lasers , my 80w Reci tubed was not as good on very small lettering.
Considering the price , I was very impressed.
The chinese lasers actually need to be set up for backlash compensation at various speeds to get the absolute best out of them , some mainstream lasers also have this , tho it's called tuning or something like that.
Thruput on my chinese lasers is around 1/2-2/3rds of my fastest spirits (which are super quick)

[Robert Silvers]

Note that 4 points on mine is actually 0.056 inches (there are 72 points to an inch in the real world. Not sure what Corel is doing, but 20 points is always 0.278 inches).

5 points is 0.069" - about 1/16.

I did this at 200 mm/sec. Maybe I should do one at 50 mm/sec and see if that is any better.

I can email you my file in AI, EPS, or DXF if you want to output it. on yours.