Engraving Comparison - GWeike vs. Epilog

[Dan Wilhelm]

I have now engraved nameplates for work on both my GWeike LG500 and my Epilog Min24. I thought some prospective laser owners might appreciate a side-by-side comparison of the engraving quality between the 2. The letters in the image are about 3/4" tall, and all of the pertinent settings appear above the examples.

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[David Somers]

Dan,

That is quite a difference at this magnification. What is the substrate?

Are the two machines similar in age/use?

Thanks for sharing this.

Dave

[Dan Wilhelm]

It is Rowmark LaserMax, black on white. The GWeike has less than 100 hours of run time on it, and the settings used on it were the best looking of MANY test runs. It really does look passable for a 2" x 8" office nameplate, but you're right...at that magnification, it looks terrible.

I don't really know how many hours are on the Epilog. It was made in 2009, and the laser tube was recharged in 2012. There was a fire on the cutting bed in 2013, and it was totaled by the insurance company. I rescued it from the scrap yard, and have restored it.

[Clark Pace]

Interesting. I think I'll do an engrave on some of my laser laserable ipi plastic and post my results. I have a Shenhui 350 and a Redsail x700. Love my Redsail!

[Clark Pace]

Hey what about speed times?

[Dan Wilhelm]

Hey what about speed times?

I'm not sure what you're asking. Total time to engrave/cut a nameplate? On the LG500 it takes about 15-20 minutes depending on the length of the name. On the Mini, it takes about 3-5 minutes. 70% speed on the Mini looks WAY faster than 250 mm/s. Not sure how fast, though.

[Ross Moshinsky]

First, for the millionth time, you want to run Chinese lasers at 500mm/sec as often as possible. They are already slow. Why run them slower? Your Epilog is running at ~1400mm/sec at 70% speed. Also stop running the Epilog at 70% speed. Run it at 90-100% speed. Absolutely no reason to run slower than that with plastics.

Second, your quality difference is down to the dramatic difference in DPI. 250dpi vs 500/600dpi is a significant difference.

[Dan Wilhelm]

First, for the millionth time, you want to run Chinese lasers at 500mm/sec as often as possible. They are already slow. Why run them slower? Your Epilog is running at ~1400mm/sec at 70% speed. Also stop running the Epilog at 70% speed. Run it at 90-100% speed. Absolutely no reason to run slower than that with plastics.

Second, your quality difference is down to the dramatic difference in DPI. 250dpi vs 500/600dpi is a significant difference.

I don't know where the condescension is coming from because that is the first time I have heard those figures, from you or anybody. Plus, running the Chinese laser at 300+ mm/s makes it shake pretty violently on the stand it came with, so that's probably not a good idea. If I had a large production engraving business, I would probably figure something out to run it faster, but I don't. Also, I'd rather take it easy on the Epilog laser tube and run it at lower speed than run it faster at a higher percentage of laser power.

I knew there would be a difference in quality between the two, but I just provided this example to those wondering exactly how large the difference is.

[Bill George]

I run my Chinese laser at 400 /mm sec and if it would go faster I would run it faster. NO shaking on my machine.

[Bert Kemp]

I have now engraved nameplates for work on both my GWeike LG500 and my Epilog Min24. I thought some prospective laser owners might appreciate a side-by-side comparison of the engraving quality between the 2. The letters in the image are about 3/4" tall, and all of the pertinent settings appear above the examples.

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Were these both run at 600 dpi? and if not then its apples and soap, need a comparison at the same speed and dpi to give a fair analysis.

[Dan Wilhelm]

Were these both run at 600 dpi? and if not then its apples and soap, need a comparison at the same speed and dpi to give a fair analysis.

As far as I know, I don't think you can set the dpi on LaserWorks software that comes with the Chinese lasers. According to Ross, it's about 250 dpi. If so, then it is the default and the max. The default on the Epilog driver is 600 dpi, and the max is 1200.

[Kev Williams]

Yes the DPI (or more accurately, lines per inch) can be adjusted-- on my program it's called "gap", I know on some other software it's referred to as "interval"-- it's expressed 100ths of millimeters. Example-- .05mm is just under .002", which is exactly 500 lines per inch. .04mm = .0016", and 1/.0016= 625 lines per inch. So the higher the number, the less the DPI.

That's the Y axis settings. As for X axis settings, 'western' RF lasers can be set to fire at X-times per inch, aka pulses per inch, or PPI. My machines are variable from 75 to 1200 PPI. But 'eastern' DC lasers, to the best of my knowledge, don't pulse at all, the beam is either ON or OFF. I'm not sure of the pro's or con's of no pulse adjustment, but I do know that DC lasers do not react as quickly as RF lasers.

Bert mentioned a comparison test at approx. the same settings. Here you go--

One of these was engraved on my old 25w western ULS, 100 speed and 50 power, @ 500 lines per inch and 600 PPI-
The other was engraved on my 80w eastern Triumph, 700mm/sec and 14 power, @ .05mm gap (500 lines per inch) and of course, who knows what PPI if any... ;)
These are also 3/4" tall, material is Rowmark brushed aluminum lasermax. Both took just over a minute.
(I would've done a test S with the LS900 but it's running a cylinder job at the moment!)

So, which machine did which? :D

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[Kevin Gregerson]

Yes the DPI (or more accurately, lines per inch) can be adjusted-- on my program it's called "gap", I know on some other software it's referred to as "interval"-- it's expressed 100ths of millimeters. Example-- .05mm is just under .002", which is exactly 500 lines per inch. .04mm = .0016", and 1/.0016= 625 lines per inch. So the higher the number, the less the DPI.

That's the Y axis settings. As for X axis settings, 'western' RF lasers can be set to fire at X-times per inch, aka pulses per inch, or PPI. My machines are variable from 75 to 1200 PPI. But 'eastern' DC lasers, to the best of my knowledge, don't pulse at all, the beam is either ON or OFF. I'm not sure of the pro's or con's of no pulse adjustment, but I do know that DC lasers do not react as quickly as RF lasers.

Bert mentioned a comparison test at approx. the same settings. Here you go--

One of these was engraved on my old 25w western ULS, 100 speed and 50 power, @ 500 lines per inch and 600 PPI-
The other was engraved on my 80w eastern Triumph, 700mm/sec and 14 power, @ .05mm gap (500 lines per inch) and of course, who knows what PPI if any... ;)
These are also 3/4" tall, material is Rowmark brushed aluminum lasermax. Both took just over a minute.
(I would've done a test S with the LS900 but it's running a cylinder job at the moment!)

So, which machine did which? :D

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ULS on the left triumph on the right.

[Dan Wilhelm]

Yes the DPI (or more accurately, lines per inch) can be adjusted-- on my program it's called "gap", I know on some other software it's referred to as "interval"-- it's expressed 100ths of millimeters. Example-- .05mm is just under .002", which is exactly 500 lines per inch. .04mm = .0016", and 1/.0016= 625 lines per inch. So the higher the number, the less the DPI.

That's the Y axis settings. As for X axis settings, 'western' RF lasers can be set to fire at X-times per inch, aka pulses per inch, or PPI. My machines are variable from 75 to 1200 PPI. But 'eastern' DC lasers, to the best of my knowledge, don't pulse at all, the beam is either ON or OFF. I'm not sure of the pro's or con's of no pulse adjustment, but I do know that DC lasers do not react as quickly as RF lasers.

Bert mentioned a comparison test at approx. the same settings. Here you go--

One of these was engraved on my old 25w western ULS, 100 speed and 50 power, @ 500 lines per inch and 600 PPI-
The other was engraved on my 80w eastern Triumph, 700mm/sec and 14 power, @ .05mm gap (500 lines per inch) and of course, who knows what PPI if any... ;)


Well, that's useful information. The default in LaserWorks is 0.5mm, and as you can see in my comparison photo, I ran this one at .1mm. I never made the connection between that parameter and dpi. Does it actually change the number of times the laser fires per inch horizontally (assuming x-swing)? I guess that's why I never made the connection because I though it just adjusted the gap between scan lines, so vertical resolution.

The "S test" was purely arbitrary because I had two nameplates on the same substrate from the two different lasers, and the only letter they shared was an S. They were visibly different to the naked eye, and I had a USB microscope handy, so I made the comparison. Little did I know it would teach ME something about how to use my own Chinese laser.

[Kev Williams]

I may have misunderstood you somewhat the first time, but no, the "gap" changes nothing horizontally, it only affects lines per inch vertically. Note that your .1mm setting equates to .0039", which = 256 lines per inch, that's less than half the resolution you ran the Mini test. For fun, run another test "backwards"; run the GWeike at .05 gap and the Mini at 250 dpi... :)

And KG- you're correct-

[Bert Kemp]

Thanks Kev, but if I'm not mistaken both your machines are much better the a gewiki LG500. so your results look much better.
If some one has one of the top 3 and a cheap Chinese or maybe someone with an LG 500 could laser an S at 600dpi and about 70% speed then we could compare it to Dans epilog S

[Kev Williams]

I don't know that my Triumph is "much better", it's a huge 1300x900 cutting machine and cost less than your FSG4- but I'm getting good engraving results from it (cermark notwithstanding) ;)

[Clark Pace]

I run my shenhui and redsail both at 400mm a sec and don't have any table shaking. I've never tried faster.

[Kevin Gregerson]

I may have misunderstood you somewhat the first time, but no, the "gap" changes nothing horizontally, it only affects lines per inch vertically. Note that your .1mm setting equates to .0039", which = 256 lines per inch, that's less than half the resolution you ran the Mini test. For fun, run another test "backwards"; run the GWeike at .05 gap and the Mini at 250 dpi... :)

And KG- you're correct-

If you want cleaner lines on the outside you can change up the density settings, it'll slow it down though.

[Dan Wilhelm]

Thanks Kev, but if I'm not mistaken both your machines are much better the a gewiki LG500. so your results look much better.
If some one has one of the top 3 and a cheap Chinese or maybe someone with an LG 500 could laser an S at 600dpi and about 70% speed then we could compare it to Dans epilog S

I'll try the 0.5" test on the LG500 when I get the exhaust re-configured, but for now, it is down. But I ran a LOT of test pieces to get the name plates to look as good as they did in the first place. And like I said, from normal viewing distance, they don't look bad. But an Epilog has a very noticeable improvement in quality.

If the gap measurement only affects vertical scan line spacing, I don't see how adjusting it will improve the tearout I'm seeing along the side of the LG500 S. I can see how running the laser faster at a higher power level would get rid of some of the thickness variation, though. I wish I could run this thing at 500 mm/s without it shaking itself apart.

[Pete James]

Make sure your backlash settings are correct if you are engraving bi-directional.

[Clark Pace]

Ok here is my RedSail x700 Laser. 400mm sec .07 scan gap 30 power. Took about 2 mins exactly. Romark Laserable plastic yellow on black.

My redsail cost $3300 after shiping taxes etc.. To my door. I don't consider that too expensive? I have been very pleased with my Redsail. I owned two uls machines long ago. They were fine machines, but I could not justify spending that much again this round. Not for what I do.

I have not heard many of you having redsails here? I wonder why?

Oh yea my laser is a 50watt

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[Jerome Stanek]

[QUOTE=

If the gap measurement only affects vertical scan line spacing, I don't see how adjusting it will improve the tearout I'm seeing along the side of the LG500 S. I can see how running the laser faster at a higher power level would get rid of some of the thickness variation, though. I wish I could run this thing at 500 mm/s without it shaking itself apart.[/QUOTE]

On my LG500 I ran a test at 500mm and the machine didn't shake. Some thing may be wrong with your ramping

[Mike Chance in Iowa]

As far as I know, I don't think you can set the dpi on LaserWorks software that comes with the Chinese lasers. According to Ross, it's about 250 dpi. If so, then it is the default and the max. The default on the Epilog driver is 600 dpi, and the max is 1200.

The default on the Epilog may be 600 dpi, but you can change it down to as low as 75 dpi. A more appropriate test would have been to lower the Epilog's dpi setting to match. The previous example cannot be compared.

[Dan Wilhelm]

I love how the "S test" is a thing now. I admit, knowing what I know now, that my original test wasn't a fair comparison between the two machines. But I still thing it would be a great resource to have a repository of similar samples from different machines so that people can see the difference in their abilities.

[Mike Null]

Dan

I would question the value of such a thing because it wouldn't accurately portray machine capabilities because of the variance of people abilities to use the machine.