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William Jenkins
02-08-2010, 9:48 PM
Well I have finally gotten my laser woohoo. Have played around one some granite and am happy with the results (attached). The laser uses a 60watt watercooled system from China. I am thinking of playing with my iPod next hehe. When reading power settings that others have used that have Epilog or Universal systems, would those settings be comparable or is there a difference? TIA
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Gary Hair
02-08-2010, 11:21 PM
The amount of power and speed required to engrave any given material will be very similar on any laser. What you have to keep in mind are the different ways power and speed are expressed and convert for your machine. For example, my laser is 30 watts and runs at 80 inches per second. So if I lasered something at 100% power and 20% speed, it would be 30 watts and 16 inches per second. The settings for your machine could be calculated using that information. For you to get 30 watts you would use 50% power, not sure what speed you would use because I don't know how fast your machine runs. To throw in another variable, you would ideally use 100% power on your machine and adjust the speed to give the best results, you might as well use the max power and, in theory, get the fastest speed.

Good luck!

Gary

James Jaragosky
02-08-2010, 11:45 PM
The amount of power and speed required to engrave any given material will be very similar on any laser. What you have to keep in mind are the different ways power and speed are expressed and convert for your machine. For example, my laser is 30 watts and runs at 80 inches per second. So if I lasered something at 100% power and 20% speed, it would be 30 watts and 16 inches per second. The settings for your machine could be calculated using that information. For you to get 30 watts you would use 50% power, not sure what speed you would use because I don't know how fast your machine runs. To throw in another variable, you would ideally use 100% power on your machine and adjust the speed to give the best results, you might as well use the max power and, in theory, get the fastest speed.

Good luck!

Gary
Another thing to keep in mind is ppi and wavelength frequency. the US machines can adjust their frequency, yours is preset, My guess is at 20k.
I may not have the correct termonology but some will chime in to correct me if I am off.
good luck with the new machine.

Doug Griffith
02-08-2010, 11:54 PM
Another thing to note is that stated power is not measured power. A 50 watt may put out 48, it may put out 55. It may put out ???. All machines are different.

Then there's the inevitable power loss over time. Who knows the condition of the tube when the settings were stated.

Rodne Gold
02-09-2010, 1:02 AM
Power density is what matters most , IE the power over the spot size. Bear in mind a laser does not fire a continual beam , it treppans , IE fires spots or cuts by drilling small holes. A similar powered laser with a smaller spot size will mark and cut differently to the same power laser/tube with a larger spot size and might require very different speed and power values.
The prime objective when testing settings is to get the best possible or acceptable output in the shortest time so I suggest starting out with the highest speed possible and reducing it.
However, Lasers generally have a pretty wide band of settings where they work ok , so its not that difficult to determine a setting that will work for you on various materials, you generally dont have to be 100% spot on (so to speak) to get good results. Start out with similar settings to other 60w systems , bearing in mind how your lasers speed is divergent to others and you should be able to tune it easily.

Michael Hunter
02-09-2010, 7:02 AM
Be aware when trying to convert, that speed and power settings are not necessarily on linear scales.

My only experience is with Epilog, where the speed scale is more like logarythmic : slow (1 - 10%) is very slow, but medium (~50%) is really quite fast and definately much more than half the maximum speed.

Nonetheless, other peoples settings will give you an indication of a suitable starting point for experimenting.

Viktor Voroncov
02-09-2010, 10:25 AM
Be honestly - for quality and durable engraving on stone better use impact engraving with diamond needles.

Dan Hintz
02-09-2010, 9:15 PM
Be honestly - for quality and durable engraving on stone better use impact engraving with diamond needles.
And you came to this conclusions based upon what evidence? A laser can have a significantly finer level of detail than a physical needle, and the durability of stone is the same regardless of what is used to carve it. You may get a deeper cut with a needle, but you didn't list that...

Rodne Gold
02-10-2010, 1:57 AM
The impact printers such as the Roland Metza are very problematic and are devices that are severely limited in respect of what they can do compared to a laser. If a pin goes , you are in trouble

However lasers and some stone like marble actually dont "engrave" , but you can still achieve sandcarving effects if you use a laser to ablate a mask and then sandblast with a fine grit.

Viktor Voroncov
02-10-2010, 4:17 AM
Hi, Dan,
I sell laser engravers and we are manufacturing impact engravers. So I have some experience in working with both types of equipment. Our impact engravers are not the same as Metaza - more oriented to big jobs like tombstones and monuments.
We made some kind of manual for dealers which is below (without pictures as they weight more than allowed)



LASERS FOR ENGRAVING ON STONE.

When dealers start sells impact type engraving equipment, first problem they have faced is questions from potential customers about comparison with lasers. Generally speaking lasers ARE NOT SUITABLE FOR STONE ENGRAVING AT ALL.

There are few reasons:
1) Laser DOES NOT ENGRAVE – laser just changes color of surface to white matt. This is the reason why to have best results you need BLACK POLISHED GRANITE for laser. You can’t engrave on grey, brown or other colored stones.
2) As laser just matt surface, while raining or just when air is very humiliated – image disappeared.
3) Lasers have TABLE and have some limits on maximum weight of stone and maximum dimension of stone.
4) Very often people compare price of impact engraver with price for Chinese laser with glass CO2 tube. It’s big mistake. Glass tube has very big fluctuation of power due unstable cooling with water cooler. If you will see temperature counter on cooler – numbers on it always change 21-22-23-24-23-22-21 and etc. Change in 3-5 degrees give you change up to 15% in power. So engraved image will be also not the same.
5) Another problem of Chinese lasers with glass tube is general instability of operations. It’s acceptable for cutting paper, but if something wrong will be with expensive stone – price of mistake will be too high.
6) Last but not least problem of Chinese equipment is bad accuracy on big formats.

But same time lasers have their own advantages –
1) Higher speed
2) Higher resolution (up to 1000 dpi in comparison with 280 dpi maximum resolution on impact engraver)
We have 21 customers who have both equipment – impact and laser. ALL OF THEM start from impact and buy laser after. They use laser to make tombstones I have named FASHION – like this one. Here laser engraving was made on glass and inserted inside stone monument.

Another sample of application is engraving of landscapes, clouds, water and other objects where high resolution is required.

All lasers we sold to stone market were GCC Spirit GX 40 Wt with redesigned frame construction to accept heavy stones.

Rodne Gold
02-10-2010, 6:25 AM
Most users here are not tombstone suppliers and are aware of the weight restrictions of their lasers.
Please don't hijack threads ... this thread wasnt about the machinery thats required for tombstone engraving.

Bob Davis
02-10-2010, 9:26 AM
Fair go, guys. Victor may have been slightly off-topic, but his reply was in reference to points that were raised by others after his post.

Dave Russell Smith
02-10-2010, 11:51 AM
Thanks Viktor for the interesting read what you said makes sense, Rodne give him some slack he was just giving his 50 cents worth this is a democratic forum I hope. :)