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John Barton
09-11-2008, 7:29 PM
Hello everyone,

I am at a factory that has a no-name Chinese laser. It uses LaserCut 5.0 drivers. The laser is a 60 watt, glass tube, air, and stepper driven.

I have some leather that I cannot cut no matter what settings I use.

The types of leather we use are vegetable tanned (tooling leather), oil tan, and chrome tan.

The veg tan and the chrome tan cut fine.

The oil tan, whether it's 1.5mm thick or 2.5mm thick, will not cut. The laser will blister the surface and that's about it. If I do multiple passes then sometimes it will make it all the way through but not without significant damage to the leather.

After searching the forum it seems to me that I might be able to do something with the PPI. I know what this on the Universal we have but have no idea how to adjust it on the Laser Cut software. I found something called Pulse Unit and something else called PWM. I think the Pulse Unit is the PPI but it requires some calculation and I am not sure how to do it.

Here are two screenshots - any help will be rewarded with heaps of karma points going your direction!!!

http://www.jbcases.com/LaserCut-PulseUnit.jpg
http://www.jbcases.com/LaserCut-PWM.jpg

Phil Salvati
09-11-2008, 7:58 PM
I can't help you with the PPI on your machine but....

We Vector and Raster quite a bit of leather here.....

Did you try wetting the leather to keep from blistering it?

Phil

John Barton
09-11-2008, 8:29 PM
I can't help you with the PPI on your machine but....

We Vector and Raster quite a bit of leather here.....

Did you try wetting the leather to keep from blistering it?

Phil

No but I will. I suspect it's something in the leather. Both of my oil tans, 1.5mm and 2.5mm won't cut at all. The veg tan and the chrome tan nappa don't blister and cut cleanly.

Thanks for the tip.

Eric Fuller
09-12-2008, 8:12 PM
I know the pulse unit is a measurement of how much the stepper motors move per pulse. If you mess with that setting, your dimensions will change...i.e. you import a 1" square and cut a 1" square. Mess with that value and you won't get a 1" square anymore. So, if you mess with them, make SURE you write down the factory value.

The other is the PPI setting. Confusing thing is that you can also specify that setting on the cut command from the main menu. I'm still working on that.

John Barton
09-12-2008, 11:50 PM
Update: After contacting Leetro, the people who make the LaserCut software, I have been informed that with their software it is not possible to change the PPI of the machine if it's a glass tube machine. They said that it's possible with a metal tube machine but did not elaborate on how to do this.

Still can't cut the darn leather. I am going to upgrade the machine to 80w anyway, costs $400 more but at least I will have the max power available from this supplier.

On Monday I am going to another machine shop that just bought a laser for $125,000 USD in China. So if their can't cut this stuff then I just have to stick to die cutting it or using plain old scissors.

The tip with wetting the leather reduced the blistering effect but still made no real cut on the leather.

Thanks for trying to help!

John Barton
09-15-2008, 12:40 AM
The $125,000 laser did the trick. The thing is as big as tractor. It cut through the leather effortlessly. I think our problem is a power/focus issue and not the type of material.

I am not basing that on the fact that the big machine cut the material so easily but instead on the problems with ours on other materials.

Sandra Force
09-17-2008, 2:51 PM
John,

A large part of your problem is density of the oil tanned leather. Because of how it is saturated with oil during the tanning process it is much denser than the other two types of tanning. Vegetable and Chrome tanning is pretty much a surface type thing and that is why oil tanned leather is so much more durable of the three. I don't think that there is anything you can do to improve your ability to cut oil tanned leather with your machine.:cool: