How many watts?

[Bryan Cowan]

I've been toying around the idea of purchasing a CO2 laser system, but with all the different watt lasers available, my head is spinning.

What I'd like to accomplish:
Mark and cut all the materials any CO2 laser can work with. I don't anticipate cutting anything larger than 1/2" thick. At this point, speed is not of the essence (I'm not in any business, nor plan on starting one any time soon).

In these systems, what is watt correlated with, speed or power? Will a 25 watt laser do everything a 75 watt laser can except move as quickly? Would a 25 watt laser need multiple passes than what a 75 watt laser can do in one pass? (Both are related to speed of completing the project).

Any help would be appreciated.

Thanks,
Bryan

[David Fairfield]

Hi Bryan

In theory, yes, but based on practical experience, the answer is "not quite." One issue I have using several slow passes of my 35 w to get through thick material is a lot of smoke staining. I think when you do half cuts in wood, the semi burned material at the bottom of the groove generates soot that would have been vaporized by higher power single pass. I can't say I've actually compared the same material cut by a higher wattage machine, so take this as an educated guess.

I'd recommend getting extra wattage and size if you can afford it. So far, I'm happy with 35 w 12 x 24. Does everything I need.

Dave





In these systems, what is watt correlated with, speed or power? Will a 25 watt laser do everything a 75 watt laser can except move as quickly? Would a 25 watt laser need multiple passes than what a 75 watt laser can do in one pass? (Both are related to speed of completing the project).

[Mike Null]

In most cases I prefer to take multiple passes rather than burn the material.

It is not often that I have to raster in more than one pass but I have found that powder coated materials look better with two passes. My machine is a 45 watt.

[Scott Shepherd]

It also depends on what you are trying to do. If the cap sheet on a product is .001" thick, then it won't take much power to get through that cap sheet, exposing the core color. So you can probably run it at 100% on the 25 watt system. Plug in 75 watts, you're still running at 100%, just less power. So it's all relative to what you are trying to cut.

If you are vector cutting shapes or letters, the more power the better. If you are engraving, it doesn't always work like that.

[Bryan Cowan]

Are multiple passes only in regards to vector cutting? Or are multiple passes necessary while rastering as well?

[Bryan Cowan]

I'd like to cut wood, paper, acrylic as well as raster glass, tile, wood, fabric, etc. Basically, if a CO2 laser can engrave/vector the material, I want to be able to do it. Determining the necessary wattage is key.

[Scott Shepherd]

Some items can certainly take multiple passes for rastering. Not too much with laser friendly products, but once you step outside the laser product catalogs, you open up a new world, all with different circumstances. I've done some engraving in ebony wood and it took more than 5 passes at full power to get the depth I wanted. In other cases, the material can be super quick to melt, so you can't overpower it with high power to get your depth. You're forced to take light cuts to get the depth so the edges don't melt.

Just depends on what you're cutting.

What you described you want to do, I'd get the most power I could afford and then go one step up from that (until it hurts).

Some times you can't do multiple passes. For instance, if you want a good finish on a thick piece of acrylic, you'll want to do it in one pass. 2 passes will leave a line and you'll have to flame polish it out (along with some elbow grease).

There is no hard fast rule. It's all different and depends on the situation, what you're trying to accomplish on that material, and what the material is.

[Brian Robison]

Bryan, make sure to check out usedlasers.com too. if you don't mind a used CO2 laser.
Rob may be able to help you out. He's on here quite often.

[James Jaragosky]

Someone posted this link in another thread. Sorry forgot who but I saved the link as I consider it a awesome deal.
http://www.ulsinc.com/promo/doublepowerlease0808/
I am not endorsing one brand over another but 2x the power for the lower price is a huge savings no matter from whom you get the unit.
my only suggestion is get at least 40w and make sure you have air assist, nice add-ons would be a vacuum table and a honey comb cutting grid but there are work around's for these options, and if you search this forum you will find plenty of information on how.

[Angus Hines]

You can never have enough power.....Get the biggest you can afford and then some....

I'm sorry now that I didn't go ahead and get the 100watt for a mere 5000 more.:mad:

[Bryan Cowan]

You can never have enough power.....Get the biggest you can afford and then some....

I'm sorry now that I didn't go ahead and get the 100watt for a mere 5000 more.:mad:

From a business perspective yes, but from someone who just wants to have a new "toy", why should I break the bank if there's no real reason for it?

[Dan Hintz]

From a business perspective yes, but from someone who just wants to have a new "toy", why should I break the bank if there's no real reason for it?
I suppose you could say the 35-45W machines are the workhorses of the small- to mid-size engraving industry. Even if it's just a "hobby", most 1/2" material may not provide you with a satisfactory cut at the lower wattages, it all depends on your expectations. As some have said, expect a lot of charring and possibly uneven edges... if you'll be hand sanding after cutting and don't care about waiting an eternity for an item to cut (expect no more than one to two inches per minute cut speed at 25W), this isn't a deal breaker. A 60W will not only be 2-3 times as fast, but the cut will be much cleaner, requiring less work afterwards. Acrylic, for example, can be particularly nasty if the cut doesn't go completely through on the first pass, splattering the melted dross outside the cut line. It comes down to what you're willing to put up with for rework and quality.

[David Fairfield]

From a business perspective yes, but from someone who just wants to have a new "toy", why should I break the bank if there's no real reason for it?

The sort of projects you have in mind, and the sort of materials you want to cut are a big factor. Maybe we can advise.

I usually run my 35 w at around 50% speed, sometimes a lot slower to get the maximum precision I can get out of it doing miniature work. I also do Christmas ornaments for my front yard out of 1/4" plywood, its relatively slow but does the job in one pass and a LOT faster than hand cutting on a jigaw.

The only times I've wished for more speed is doing repetitive boring industrial stuff, like cutting multiple complicated gaskets out of sheet stock when I was already running at 100% speed, and more power wouldn't have made a difference. So I can't say that I've shortchanged myself on power.

Let me add that the laser is possibly the best toy and coolest hobby tool that money can buy. Now I want a CNC vertical mill, CNC lathe and a 3d printer and I'm set ! :rolleyes:

D

[Mike Null]

There are a lot of engravers who are doing nicely with 25 watts.

[Dana Florian]

30 watts is plenty. I purchaced a 30watt gcc explorer about 2 years ago and am still amazed what you can do with it. We run this in an industrial atmosphere. We have multiple cnc wire edms, conventional edms, surface grinders mills etc. Dont spend the extra five grand for 40watt, it wont do any more than the 30. good luck

[George M. Perzel]

Hi;
I primarily work with wood so will comment regarding same. Based on your statement:
"What I'd like to accomplish:
Mark and cut all the materials any CO2 laser can work with. I don't anticipate cutting anything larger than 1/2" thick. At this point, speed is not of the essence (I'm not in any business, nor plan on starting one any time soon)."

Get at least 100 watts if you want to cut most standard domestic hardwoods up to 1/2" without taking forever and multiple passes tend to get messy. Some of the exotic woods will be tough to cut even with 100 watts-may get through 1/8" ebony without too much of a fire but doubtful.

I suggest you spend a week reviewing old threads on this forum regarding laser purchase recos- a lot of wisdom and experience in these files-before you define the "must have" specs for your purchase. Good Luck
Best regards;
George
LaserArts.
Goo

[Bryan Cowan]

Thanks everyone for your replies. From what everyone has said and from some examples I've seen, it gives me a good idea of what I would be comfortable with and seems to be 35 watts. :)

[James Stokes]

With only 35 watts you are not going to be cutting 1/2 inch wood.

[Bruce Volden]

Been doing this since 1995 with a 25 W machine. 2nd machine also 25 W. 3rd is a 35 W. This is just me but, look for a LARGER table size! I've seen laser cuts on 2 X 4s -UGLY! It boils down to spot size (focal point) and it ain't near a table saw.

The larger table size would allow for larger gunstocks, or sheet goods,medallions......what have you, to increase through-put. This =$ca-ching$!

Sometime things are not all about power. You can have a 100 W machine and run it wide open (100/100) and get good results, or have a 25 W and run it 60/ 35 and look equally impressive. If you really want to "burn" down there you have to remember that "centers" will sometimes chip off. Imagine the letter "o", see the center, I've broken the center of a few "o's" by being too deep!! Anyway look down the road and PLEASE continue to ask questions-that's what we're here for. That, and have new folks take money out of our pockets :D .

[Larry Bratton]

Bryan:
Are you any closer to knowing which wattage to buy?

If it's going to be a hobby machine, a 60 watt machine or even less would allow a lot of enjoyment. I have a 40 watt with a 36 x 24 table and it is a work horse. If I was going to spend money on more wattage I would go for a 100, but I can't afford it, sooo the 40 works for me. Just my two cents worth.

[James Jaragosky]

Anyway look down the road and PLEASE continue to ask questions-that's what we're here for. That, and have new folks take money out of our pockets :D .
You do not list a home city in your bio.
so I do not know how far Atlanta is from you but if possible you may want to go to the IWF next week and see them all in one place, then decide.
That is my plan on a 4x8 cnc router. hope to see you there.

[Bryan Cowan]

Really leaning towards 35 watts right now. It may not cut through 1/2" wood, but I just threw that out there to see if it's even possible. Wood and I really don't get along. :)

[Scott Shepherd]

35 watt isn't going to cut through 1/2" acrylic either.

[Bryan Cowan]

Alright, good to know...not sure if I'll ever need to cut anything 1/2" thick.

[Lee DeRaud]

35 watt isn't going to cut through 1/2" acrylic either.Don't be too sure. I did an experiment with 0.44" (0.22" doubled up) on a 25W: cut through in one pass, left a nice edge, and even welded the two layers together for me. Very slow obviously, but certainly good enough for hobby work.

[Scott Shepherd]

Clear, maybe, colored, nope.

[Mike Null]

As a result of many years in the retail trade I learned one or two things which have stuck with me.

Customers can be divided into two types; 1. "I need"; 2. "I want".

We always liked the "I want" type because they could be very creative when it came to finding ways to justify their purchase. They found all kinds of scenarios where they might "really" need those extra features.

It strikes me that woodworkers fit the "I want" category. They will always buy 25 watts or so more than they need and larger tables than they need. That's fine, it's their money, but from a business standpoint you'd better be looking at ROI.

[Scott Challoner]

I have 30 Watts and I can cut through 1/2" Poplar. some woods will cut better than others. Many will char badly and leave soot. Poplar turns dark, but doesn't leave soot on your fingers.

[David Fairfield]

Concerning material thickness, also keep in mind that the precision of the laser allows you to make a sandwhich of pieces, and the edges will line up perfectly.

So for example, if your specs are for 1/2" material, you can cut the same part twice out of 1/4" material and glue it together. If you cut holes for dowels, it will line up perfectly when you assemble it. If you're fussy, you putty the seam, sand and paint and its totally solid. :)

And btw, using a two part sandwhich + putty can also eliminate edge taper, if that's an issue.

Dave

[Bryan Cowan]

Concerning material thickness, also keep in mind that the precision of the laser allows you to make a sandwhich of pieces, and the edges will line up perfectly.

So for example, if your specs are for 1/2" material, you can cut the same part twice out of 1/4" material and glue it together. If you cut holes for dowels, it will line up perfectly when you assemble it. If you're fussy, you putty the seam, sand and paint and its totally solid. :)

And btw, using a two part sandwhich + putty can also eliminate edge taper, if that's an issue.

Dave

Excellent advice, thanks

[David Fairfield]

yw, btw the same goes for oversized parts. I did a 4' wide sunburst for a customer by dividing the drawing into parts that fit within in my 12" x 24" limits, then pieced it together like a jigsaw puzzle. Turned out well.

D

[Scott Shepherd]

It also depends if this really is going to be a "hobby" or if you plan on making money with it. If it's a hobby, that's something totally different.

I can cut through 3/4" acrylic if I want, but I can't charge the customer for what it would cost me to do it. It's great to say we can cut through things, but what can you cut through that's economically sound to do?

If this is a hobby, then 35w is probably fine, but you should look at the double the power special I posted in another thread. You can pay for 30, get 60. If you plan on making an income with it, I stand by my opinion that the more power, the better.

[David Fairfield]

Extra capacity is great, but its not cheap enough to be impulsive about it. Leaving aside Bryan's focus on hobby applications, the extra capacity of higher power comes at a financial cost that has to be factored into ROI.

In my experience, the majority of everyday cutting & engraving jobs fall within 35 w 24" capability. Jobs which start to push my machine's operating envelope taper off significantly, and the jobs I have to turn away as beyond capacity are few, and would likely be beyond a 100w machine too (eg. cutting metal, marble, miter cuts, etc).

So in order to pay for the higher cost, a commercial operator would also need to be taking a significant number of jobs that he'd turn away were he operating a lesser powered and or smaller machine. That's really up to the individual buyer to figure out. Cutting lots of thick acrylic signs, go with high power. Cutting name tags or Christmas ornaments, save the bucks.

Its also worthwhile to consider that unlike traditional shop tools the machine is a robot. Once the "go" button is pushed, you can be doing something else, like I'm doing right now:rolleyes:. So running occasional jobs at a slow speed is not necessarily eating valuable time.

Dave

[Bryan Cowan]

Its also worthwhile to consider that unlike traditional shop tools the machine is a robot. Once the "go" button is pushed, you can be doing something else, like I'm doing right now:rolleyes:. So running occasional jobs at a slow speed is not necessarily eating valuable time.

Dave

One of the key points that helped my proposal in getting the FiberMark inside this building :D

[Peck Sidara]

Its also worthwhile to consider that unlike traditional shop tools the machine is a robot. Once the "go" button is pushed, you can be doing something else, like I'm doing right now:rolleyes:. So running occasional jobs at a slow speed is not necessarily eating valuable time.


One of the key points that helped my proposal in getting the FiberMark inside this building :D

Very true for both Bryan and David's applications, metals. Whether coated or raw, it's not going to catch fire in the C02 or Fiber.

When considering a C02 laser for the multitude of substrates it's capable of cutting and engraving, it is extremely important to never leave your machine unattended when cutting volatile substrates; this includes any and all materials that will/can burn when the heat of a C02 laser is applied. Wood, plastics, acrylics, etc.

[Larry Bratton]

Alright, good to know...not sure if I'll ever need to cut anything 1/2" thick.
Priced any 1/2" acrylic lately? I haven't either, but I would guess around $200 bucks a sheet. I cut 1/4" with my 40 watt in one pass. If I need a piece to be 1/2", I cut 1/4" twice, and bond it Weldon #3 or #16. You gotta look pretty close to tell it isn't 1/2" to begin with. I usually use cast instead of extruded also, it just seems to work better.

[David Fairfield]

True Peck, I may be doing something else while its running, but I've always got an eye and an ear open, and never let it out of visual range, just in case.

Its funny, but I've gotten to know some of the files I run by the rhythm the machine makes while its running them. :)

Dave

[Rodne Gold]

In a commercial application , it , in my humble opinion , is far better to get 2x lower powered lasers than a single high wattage.
We run 6 lasers , all 30w and make a much better return on them than lets say 2 x 100w machines.
If you really want to cut thick stuff like wood , a laser is not the best tool for this , we have a overhead CnC router for that .
Yeh , I would love a beam dynamics 500w laser for metal cutting etc , but at $195 000 , its but a dream.

[David Brasfield]

For me, our 120 watt Epilog gets used a lot for making intricate cuts in thick material. It is slower at it than my CNC, but it can cut sharp inside angles without tool/bit radius issues. Even though it may be slower, the setup time to cut solid wood between the CNC and the laser makes the laser far more efficient at many of our projects. That is why we purchased it.

I believe that it was Peck that did test cuts for us on the most difficult of the materials we deal with. The results directly affected our decision to purchase.

95% of the work done on our CNC is high speed cuts done on flat goods in production runs.

More and more, we are finding applications where both laser and CNC are used to complement and add value to jobs.

All the best,
David

[Charlie Bice]

It really does depend on what you want to cut.

We do a lot of cutting, but, mostly balsa, bass and plywood.

We also do production work, so speed is important to us. But, more importantly is quality.

We had a 45W before we got the 75W. At times I wish I had over 100W.

Balsa up to 1/4" cuts very cleanly with little char on the edge. The cut does have a noticable angle to it.

Ply is different. "Std" ply, like door skins, can go up to 1/4" before quality gets bad. 1/8" is really nice. Higher quality ply (called aircraft grade) is tough stuff. We can only cut 1/8". Even at 75W the 1/4" takes two cuts and then is really messy.

Time of cut is very important for cut quality. Yes, some materials can be cut with multiple passes, but, the edge will have to be cleaned up, sometimes a lot.

For 75% of our cutting, the 45W machine was just fine.

charlie

[Martin Reynolds]

My experience is that, for thinner materials, the motion system limits the laser power. The head can only move so fast, so the laser power has to be reduced.

This means that the only reason for a thicker laser is to cut thicker materials faster.

My 30W laser can cut 1/8" acrylic with ease. 1/4" is slow, and 1/2" is not a good cut.