Trotec 120 w - parameters for cutting maple and leather??

[Pierre-Luc Duchesne]

Hi folks,

I am the new to SMC and to laser engraving and cutting. Before purchasing a laser, I booked few hours this Friday with someone who has a trotec 120w (from what he tolds me this is a monster laser cutter!). I probably don't need that kind of power and because he use it in a industrial context, he is not familiar either with engraving or cutting wood and leather.

In a way to save time and money ($50 an hour!!!), what would be the parameters to starts from to burn and cut the following:

1. Marking dark text on dry maple wood?
2. Marking text on leather (light, medium and dark marking)
3. Cutting 5 ounces soft leather (1.5mm) (1/16")
4. Cutting maple 4mm thick (5/32")
5. Marking black anodize aluminum to get a nice and clear text

so for every task mentioned, I guess I should look for those adjustments:

• laser power % (120w)
• laser speed (% or inch/ min)
• laser pulse? not sure here
• what else I should look for?

It will be much appreciated if some of you here can guide me with basics parameters setting to start with. The meeting is scheduled on this friday (november 1st). Next week I will post pictures and will give you the parameters that worked better for my applications.

cheers all

Pierre-Luc

[Mike Lysov]

Do you know what kind of controller and motors are used in Trotec you are going to buy/test?
Your material is kind of thin and with 120W power it should be cut through at quite fast rate.
However if Trotec you are going to buy/test G-Code driven and comes with stepper motors you may not be be able to utilize it at a maximum possible speed/power combination.

Just as an example I have two lasers, one is a LaserPro Spirit GX with servo motors and 100W power(Synrad metal tube) and the other is a LaserLife laser with stepper motors and 280W power( 2 x 140W GSI tubes). I believe some of big powerful Trotec lasers are driven the same way as my LaserLife laser.

The Spirit seems to use a HPGL controller and it can cut through 3mm thick MDF at maximum 100% power and 4.4% speed(about 3400mm/m).

The LaserLife uses a DSP controller and even though it is 2.8 times more powerful than my Spirit GX the maximum speed I can use on relatively small 10cm wide/tall simple shapes is only 2600mm/min. And since it cannot move faster I use only 30-50% of available power at that speed.

So basically I just cannot use it at full power on thin material and small designs because 2600mm/min is a maximum it thinks it is comfortable to follow curves of small shapes.
If it had come with a driving system similar to the one used in Spirit GX lasers I would have been able to get speed up to at least 6000-7000mm/min with power set at 90%.

[Dan Hintz]

Pierre-Luc,

The settings will depend heavily upon what lens is used, but I'll assume a 2" (if it's in an industrial environment, it could very well be a 4", so these numbers will be off).

These are all from memory, so take them with a grain of salt. For anodized aluminum, you'll probably be in the 100S/20P range. For marking Maple/leather, I would expect something in the 100S/50P and up range to give you a nice mark... you may want to slow it down and take it out of focus a bit for a darker mark. For cutting the Maple, this is more of a guess as I don't know how far Trotec slows their machines down for vectoring, but likely something around 60S/100P (someone else please confirm/deny). On my 60W ULS I would use around 30S/100P.

[Scott Shepherd]

Yes, that's a really tough thing to give if you don't have one. It's not all about the power in this case. You have more than enough power, so speed will be the limited factor on some of it. You can't run but so fast vector cutting before losing quality on any laser.

I do think Dan's settings are a good starting point. They should be able to open the material database in their job control and select all of the objects you listed. That would be a good starting point as well, just using the factory defaults for those materials. They tend to be pretty close. I know the anodized aluminum one was really good for my machine, I assume it's equally as good for their machine with their power combination.

Ask them about using the factory settings in their material database as a place to start.

[Pierre-Luc Duchesne]

Thanks Myke,

No clue of the controller and seriously the guy who owns the machine does not seems to be really into computer so having this information might be a project as well. I will try to find out once I will be there and let you know with parameters used.

Again, thanks!
cheers

[Pierre-Luc Duchesne]

Thanks Dan,

It's a good start and gives me a better idea where to begin. I will try to get the machine out of focus and see how is the mark. By out of focus, should I get the the lens closer to the material or farther?

Thanks for your time
cheers

[Pierre-Luc Duchesne]

Hi Scott, thanks for you suggestions. Will let you know what settings finally worked better. Since I remember a little the demo at troctec's place, I should not be too lost and will look for factory preset values in database.

thanks
cheers

[Scott Shepherd]

Pierre, I also know that Canada has a great Trotec setup up there. I'm sure a quick call to them would put you in contact with their tech support who might be able to give you some really good numbers to start with.

[Dan Hintz]

I will try to get the machine out of focus and see how is the mark. By out of focus, should I get the the lens closer to the material or farther?

Up or down, it doesn't matter due to the hourglass shape of the beam. Generally I shoot for raising the lens as it takes it farther away from harmful smoke and such. Figure on an extra mm or two.

[Guy Hilliard]

When engraving out of focus it is best to go + (further away) as the shape of the laser beam will continue to disperse as it burns into the piece. When cutting out of focus it is best (unless there is a specific requirement on edge shape) to focus - (closer) as the beam will then focus inside the cut.

[Pierre-Luc Duchesne]

thanks Guy, will try tomorrow.

cheers