Questions and advise as i am looking to buy a new laser for the first time

Community Laser Talk
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Hi Group

I am in the UK and I want to be able to deep 3d type engravings into metals like brass, bronze, alley, steel and stainless as a main job for the machine, but as well as other stuff like general laser etching and marking and hoping to potential play with and use colour marking too.

I would like to ask:

  • Laser power
    if i can afford 100 watt or more is it a no brainer to get this power level?
    I guess my concern is that i won’t be able to do more delicate stuff as perhaps the beam is to big or too hot etc…
    Or will be perfectly ok to do my deep 3d type engravings with a lesser power machine say 60w or even 30w thus saving money

  • what to look for when choosing a laser
    I guess i need a Mopa fibre laser but what do i look for when choosing, i.e laser power, laser frequency, marking speed etc…
    is there some base minimums i need to get and then if the numbers are higher then it is better?

  • engraving depth
    I have seen this listed on some laser specs, does this mean maximum depth full stop i.e it won’t go any deeper or does it mean it can cut 2mm depth in one pass?

  • machines to go for:
    I have looked at a couple of machines around the £6k mark i.e:
    “cloudray” i think they have a JPT M7 machine i looked at so i assume it has a jpt laser source?
    and
    “wisleylaser” who offer a JPT mopa laser and they offer a jpt laser source or a Raycus laser source
    are both these good companies to buy from or are there better ones to choose from?

  • Expected service life
    i have seen 100,000 hours listed is this a real figure will they run this long?
    and does this depend on power and what i am doing or is it purely on the hours of use?
    what happens at 100,00 hours is it new machine or a new laser source?

  • fume extraction
    do i need a proper self enclosed filter box that runs in the same room as the laser and exhaust air to the same room but the filters catch all the junk, and dangerous stuff, then i just change filters
    and if so are these expensive to run?
    Or can i just stick a 100mm pipe to out side and its ok?

do i need to consider anything else?

it’s a major purchase and decision so I hope I get some good feed back to help me make a decision to make a purchase.

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Looks like you did enough research to ask the right questions. I have only Diode machines, so I will only respond where that would be relevant. I will leave the machine selection to those that have them.

Laser Power
With a given machine, more power means you can complete a project faster. What is often not considered is how low will the power go? Not everything gets engraved at full throttle.

What to Look For
Depends entirely on what type of laser it has, Diode, CO2, Fiber, IR, and RF. No one machine fits all. MY choice would two lesser expensive machines. I would rather be able to do two different materials slower than not be able to do one of them at all. Yeah, I know, 3 diode machines kind of limits my options.

Engraving depth
Without changing the laser head height, this is controlled by DoF, or depth of focus. Some machines have a long DoF (Sculpfun diodes) and some have a very narrow range, like IR lasers. For CO2 lasers, the DoF varies with the lens chosen, so you buy multiple lenses to go with it.

Machines to go for
I hope @jkwilborn jumps in here and offers his expertise. He has a vast experience with the type of machines you propose. I will say this… Search the forum for each machine you are considering. Here you will get to read the negatives that should be considered before purchase.

Expected Service Life
Depends entirely how well you maintain the machine and the operating environment.

Fume Extraction
I have the new Sculpfun iCube 10w laser which has a paper and a carbon filter. I am using it indoors. A 3-5 minute burn is not bad, with some odor that dissipates within an hour or so. But a 10 minute or longer burn is not so good. My two machines at home are both vented outdoors. I recommend this unless you are operating in a carport.

Read or watch everything you can. Even the bad information can be useful.And be active on the Forum. You may find solutions to problems you did not know you had.

And… G O O D L U C K ! ! !

2 Likes
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Hi MikeyH

Thankyou for your reply, and help and info.
I will delve into other posts in this forum to see what els I can find.

Z

1 Like
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Hello Adrian, welcome to the forum.

Lots of people here have fiber lasers and each can give you their own opinion on strategy.

If you stay under 100W, the lenses are about 1/8 the cost of a lens for >= 100W.

These are all done on brass coins from Amazon. Most take an hour and a half to two hours a side on my M60 JPT M7 MOPA. All of these are straight off the machine, no secondary hand work required. The right one, which is an inverse of the center, as you can see it’s darker from the extra heat put into the coin.

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Lower power will take out less material, but it also creates more heat, doing this can damage the coin or other material by discoloration or warping from the heat.

The spot size of the lens makes a lot of difference. You have the same amount of wattage produced, but if it’s in a smaller area, it appears to be more powerful.

Staying under the 100W range will help you get a group of lenses for your varied purposes. I’d suggest you stay under the 100W range, there are 90W machines out there. I’ve done all I’ve needed to do with 60W and I don’t run it at 100% that much.

These are pulse lasers, compared to led/rf and dc excited co2 lasers. What makes them work with metals is the pulse power, how long it’s on (q-pulse width) and the number of pulses/mm (frequency). My 60W can produce 18kW pulses.

As you mentioned, these are engravers, not cutting machines. I’ve never tried to cut anything that thick, but I doubt it’s a reasonable endevour.

I made markers for my column out of this brass sheet. Took 10 passes or something, but it also warped and discolored the metal. Relatively low power as I didn’t want to damage the brass. I still had to clean them up.

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MOPA is the most versatile and the JPT is considered the most dependable from the Chinese. It appears these can run the 100k hours specified, I see few of them fail. The Raycus is usually not available as a MOPA configuration and they are considered to be behind the JPT for dependability.

MOPA allows the maximum ability to control the pulse.

I’ve heard really good things about Haotian laser and OMG, I got mine from Cloudray.

Any laser should be vented outside. There are particulates and different types of gasses produced depending on the material. Filters are good, but they generally don’t remove the bad stuff, just clear the smoke or particulates. A good filter system requires good filters, Russ has stated his filters are a few hundred pounds for a replacement. So he pre-filters or filters in front of the main filter to catch more of the particulates and to help keep the expensive filter element active. I believe he also vents outside after the filter system.

I have four lenses, an F100mm to an F420mm, each has specific coverage, spot size and depth of focus (dof). I find the F100mm (spot size of ~16 microns (0.016mm)) difficult to use as it’s dof is less than 1mm and you can’t get your hands or head in there to see how it’s set up. Whereas the F420mm (300x300mm coverage) has a dof of ~13mm with a spot size of ~50 microns.

Consider how many lenses you want. With an F420mm you get an 800mm tall column. If you buy a short lens machine the column is usually much shorter, so movement to longer lenses could be a problem, especially if you put a rotary in there.

If you have questions, sing out.

Good luck

:smile_cat:

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The M60 JPT M7 MOPA laser will be more versatile than 100 watts. And for most jobs you will not use its full power. Otherwise, you will burn the workpiece. Therefore, you should not overpay. Of course, you can increase the speed, but on standard Chinese scanners you will begin to lose quality and they will fail. For work at high speeds, you will need to select specialized scanners, they are more expensive.