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View Full Version : Will a 25W Trotec laser cut sheetmetal?



John Pickett
05-09-2007, 3:21 PM
I am having a difficult time cutting sheet metal (.050" thick) and engraving into steel or aluminum.

Basically, the laser will not mark the metals. \

I am using a 2.0 focal lense, power 100%, speed 5, multiple passes, and surface sprayed with LMM14 laser engraving spray.

I did discover the laser does a fantastic job at engraving anodized aluminum.

Brian Robison
05-09-2007, 3:35 PM
Hi John,
Nope, it won't do it.
You can engrave on some metals using Thermark or Cermark.
Some one can probably help me out here, but you probably need about 20,000 watts and a Yag to cut metals.

John Pickett
05-09-2007, 3:46 PM
Brian,

I would think I could at least engrave lightly into 6061 aluminum or 303 stainless steel? Yes? No?

Joe Pelonio
05-09-2007, 3:51 PM
Not with 25 watts. I can barely mark a faint image on stainless steel with 45 watts full power lowest speed. With a CO2 laser you'd need at least 100 watts with special lenses to cut thin metal. Most made for metal cutting are at least 1 KW.

Belinda Williamson
05-09-2007, 4:29 PM
I'm with the others. With 60 watts I can't cut metal or engrave stainless, only mark with Cermark/Thermark.

Dave Jones
05-09-2007, 5:47 PM
Apparently aluminum takes more power to cut than steel because it reflects the wavelength of the laser.

If you are using Thermark/Cermark, be sure you spray an EXTREMELY thin layer on the metal. It needs to just barely be on there. Too thick and it won't work.

Mike Null
05-09-2007, 8:33 PM
I agree, it takes a lot more than 100w to cut metal

My 45w will mark stainless at a slow speed with a 2" lens.

This was rastered. And without Cerdec. It is a dark gray rather than black.

John Pickett
05-10-2007, 10:00 AM
Thanks everyone for your feedback.

I am alittle disappointed I am unable to engrave metals. Damn.

I was hoping I could at least engrave something similar to what Mike posted but I guess not.

Mike Null
05-10-2007, 10:07 AM
John

Give it a try on stainless. Very high power and resolution and very slow speed. I had to raster my example as I do not have vector fonts.

(I suppose I could have changed the outline but it didn't occur to me at the time.)

Added new picture of same item. New rastered text. Straight lasering at 100p, 1000dpi, 1% s. a little unevenness shows at the top but it's pretty good and the mark is a dark as Cermark. It took 6 minutes to make the "marking stainless" image.

Mike Mackenzie
05-10-2007, 1:04 PM
These kinds of marks can be made with 25 watts only on High Carbon content Stainless steel. Not all stainless will get that dark.

Eric Allen
05-10-2007, 3:36 PM
John

Give it a try on stainless. Very high power and resolution and very slow speed. I had to raster my example as I do not have vector fonts.

(I suppose I could have changed the outline but it didn't occur to me at the time.)

Added new picture of same item. New rastered text. Straight lasering at 100p, 1000dpi, 1% s. a little unevenness shows at the top but it's pretty good and the mark is a dark as Cermark. It took 6 minutes to make the "marking stainless" image.


That looks pretty nice! How big is that "marking stainless" line top to bottom and left to right? I've been putting off getting Thermark/Cermark due to the expense, might just try this for one-off jobs.

Jeanette Brewer
05-10-2007, 5:07 PM
Basically, the laser will not mark the metals. \

I am using a 2.0 focal lense, power 100%, speed 5, multiple passes, and surface sprayed with LMM14 laser engraving spray.

Based on your original message, you are using TherMark (LMM14), aren't you?

Did it leave no mark at all on your stainless or was it just a gray mark (as opposed to black)?

I've never done a head-to-head comparison but I've been told by some that CerMark leaves a much darker, clearer mark on some materials. Have you tried CerMark instead (LMM6000)?

Belinda Williamson
05-10-2007, 5:51 PM
I am having a difficult time cutting sheet metal (.050" thick) and engraving into steel or aluminum.

Basically, the laser will not mark the metals. \

I am using a 2.0 focal lense, power 100%, speed 5, multiple passes, and surface sprayed with LMM14 laser engraving spray.

I did discover the laser does a fantastic job at engraving anodized aluminum.

Jeanette,
I think John's first issue is the one most of us responded to - difficulty cutting metals. There may be some confusion here regarding exactly what he is trying to do, which I did not realize until I read your post. There may also be confusion between the terms "engrave" and "mark".

John,
We may need further clarification. Are you having difficulty cutting, or marking, or both?

Mike Null
05-10-2007, 8:11 PM
Eric

The width is 2 inches. It is Arial 18 pt. bold that I arched.

I've had this machine for 10 months and have not had need to run stainless so this was only my second attempt at it.

I'm sure Mike Mckenzie is right about the type of stainless and how they engrave--this is a Zippo letter opener.

Larry Bratton
05-10-2007, 8:13 PM
Anodized aluminum is coated. It will raster,(engrave), as will coated brass. But actually, aren't we just marking the coating or removing it? Aluminum reacts to heat differently than steel and that's the key, not the softness or hardness of the metal.

I did some stainless steel this week using Cermark. It came out very nice and my customer really liked the result. Gave me an order for 4 more license plates at $35.00 each. It took 17 minutes to do one not including the little bit of prep time and cleanup. Wash it under a water faucet after lasering and it's like magic! The mark looks almost like it was screen printed. It is actually fused into the metal and will NOT come off. I used 100 power, 15 speed with 40watt Epi. The settings are different and opposite for aluminum, Epilog recommends 100speed/80 power for 40-45watt.

Dave Jones
05-10-2007, 8:32 PM
Anodized aluminum is unlike any other metal. It's "coating" is a thin layer of aluminum oxide crystals, grown from the raw aluminum, with a dye captured inside pockets between the crystals. The laser is bleaching the color out of the dye, making it look white. If you use too much power you can actually laser off the anodize layer. You can't go past the oxide layer with a low power CO2 laser.

Bill Cunningham
05-10-2007, 9:07 PM
This is a piece of stainless that a customer gave me to put a few things on and show him how the laser marked stainless.. This was 308 I think?

Mike Null
05-11-2007, 3:23 PM
Bill:

After seeing your beautiful and professional looking result I'm reluctant to post this but thought I should. This mug distorted badly during the marking effort. I am to blame for using settings that were probably too high, at least the dpi. In order to compensate for the roundness (I don't have a rotary device) I adjusted the focus and re-ran the job 4 times. 44 minutes total.

Just plain burnt hell out of it. No chemicals used.

Bill Cunningham
05-12-2007, 9:33 PM
I find marking curved stainless can be difficult, and sometimes impossible without a rotating thingy.. It does not take much of a curve to throw off the focus enough to lose the heat needed for fusion.. About 1/8" out of focus will usually be enough to cause the mark to fade off by rubbing. Going slow and hot, I find you can usually work to a maximum of 25% of the diameter . i.e. you can reliably put a .75" wide logo on a 3" dia. stainless mug .. Beyond that, it will probably not work too well unless you have a rotator.. The piece in the picture above is flat, and a LOT easier to do..