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Martin James
07-04-2013, 7:28 PM
Hi All. First post after days of reading. I am considering the purchase of a laser cutting machine for cutting 8-10oz veg-tan leather. (3.5mm)


From reading and speaking to factory reps it sounds like any laser wattage is fine for engraving or etching, but for cutting thicker material higher wattage is better. How many watts is best for cutting. And are there tradeoffs with a high power tube vs a low power one.


I have had recommendations range from 60 to 130 watts minimum. As well as using a lower watt machine with multi pass cuts.


If you have tips on wattage, speed, frequency, masking and cleaning edges/burns I would appreciate them. Thanks Marty

Dave Sheldrake
07-04-2013, 8:04 PM
Hi Marty,

60 - 80 watt Chinese DC Glass tubes will do it as will 35 to 50 watt RF Western sources.


And are there tradeoffs with a high power tube vs a low power one.

Replacement tube prices start to get silly once you get above 80 watts (DC Glass tubes) a 120 watt can easily cost 2x the price of an 80 watt.For example here an 80 watt is £350, a 150 watt is £2,000+

The inverse square law also applies, double the power doesn't get you double the speed, variations of "double the thickness = 4x the power at the same speed" and variants of that apply.(double the speed of the same thickness = 4x the power etc etc)

High power tubes also don't engrave very well, there is a minimum the tubes will fire at and in some cases this is above the power levels you may wish to use.

Leather smells aweful when it cuts, but does cut quite well (the fumes are unpleasant but not highly toxic)

hope that helps

best wishes

Dave

Martin James
07-07-2013, 8:06 PM
Hi Dave thanks for all the info. I am trying to make a purchase decision with limited funds and no prior laser experience. I need to cut the thicker leather without too much burning, and still want to be able to engrave paper or card stock.

I guess I don't understand the balance between not enough juice for cutting and too much for engraving.

I am looking at 600x900 machines with 60 to 130 watts tubes. At what point do the larger tubes become less usable for engraving?

Also I have a K nitrogen bottle in the shop, would that help with the leather cutting?

Thanks Marty

Dave Sheldrake
07-08-2013, 4:50 AM
Hi Martin,

80 watts (DC tubes) is about the upper limit for fine engraving or marking say...paper, above that the lowest power they will run at becomes to high for fine work (unless you invest in expensive optics).

Leather does cut well with 80 watts but it will be slower than say a 130 or 150, the actual cutting of leather liberates oils and water as well as smoke so that is what causes discolouration around the cut , Nitrogen will help but is likely false economy as the benefits won't outweigh the cost of gas (the laser head is usually too far from the job for it to work as it would in an industrial laser) In the back of my mind somebody who does a lot of leather cutting was talking about it the other day...lemme see if I can find who it was and I'll PM you a link.

RF tubes work better on leather and paper as they have some different beam properties but for what you are looking at the cost would be silly for a startup package (the sources can easily cost 20x as much as a glass tube)

Are you looking at importing or sourcing inside your own country?

(I don't sell lasers by the way) :)

best wishes

Dave

Khalid Nazim
07-08-2013, 1:48 PM
I have a Shenhui 600 x 900 80W (RECI Tube) machine and I cut leather every day. 8-10 Oz Veg Tan leather is quite thick and you might need to do multiple passes at mid level power to reduce charring. I cut 3-4 Oz Veg Tan leather in one pass at 60% power and 60mm/sec speed. For engraving I use 22% power at 500mm/sec speed.

Oiled leather is very difficult to cut and you cannot use the Veg Tan settings on Oiled leather.

Regards
KN

Martin James
07-09-2013, 4:01 PM
Hi Khalid, Thanks for the post. Do your neighbors complain about the smell of vaporized leather?

M

Martin James
07-09-2013, 4:06 PM
Hi David, Thanks for the post. I am looking at the imported machines, either direct or through a supplier here in the US. I would be interested in learning about lens choices. I think the machines I have looked at come with 40-50mm lenses as standard. I was probably going to add a longer lens so as to increase depth for engraving curved surfaces. More info or links would be appreciated.

Thanks Marty

Khalid Nazim
07-10-2013, 9:40 AM
They have not done that till now:) The houses next to mine are separated from my house and I am venting in the middle of my back yard. So there is a bit of space for the fumes to get neutralized before it reaches the neighbors.

Having said that, I have to use of lot of Fabreze (air freshener) in the basement where my machine is located even though I have a powerful exhaust system.

Regards
Khalid

Bill Cunningham
07-11-2013, 9:27 PM
I don't have any problem cutting 8oz (1/8") leather on my machine. masking it before cutting keeps the surface clean.

Martin James
07-15-2013, 11:18 AM
Thanks Bill. I had asked at Trotec about which of their lasers would cut the veg-tan leather we use and they thought I might have to make several passes on the zing 40. Is the leather you have cut the softer chrome tan or the stiffer veg tan like what they make saddles from? thanks

Andrew Becker
08-09-2014, 12:08 AM
Thanks Bill. I had asked at Trotec about which of their lasers would cut the veg-tan leather we use and they thought I might have to make several passes on the zing 40. Is the leather you have cut the softer chrome tan or the stiffer veg tan like what they make saddles from? thanks

I know this is an old thread but I wanted to chime in and say that I use a 40 watt Chinese laser and I cut and engrave 6/7 oz veg tanned leather.

David Takes
08-09-2014, 9:09 PM
It really doesn't take a great amount of power to cut leather. If you want a cleaner cut it would be wiser to work with power in the 50+ range. My shop is in leather country, so it's a substrate I likely work with it more often than many. Here is a fun little project I did the latter part of last year.

Deane Donaghy
08-10-2014, 5:07 AM
I need some advice on cutting veg tan leather with a Redsail 50W CO2.
I have been able to engrave with reasonable success, but when I tried to cut the same 3 mm. thick leather I tried multiple passes and varied the speed and power setting
but I still could not cut clean through.
I started out using 85%Power and 12 mm/sec Speed and I am using Corel Draw and Lasermate control software.
Any suggestions

294600294601

walter hofmann
08-10-2014, 5:52 AM
I have a converted 40W machine with DSP AWC608 and I cut 3mm leather with 8mm/s speed and 40% power clean cut.
check your focal distance and the optic if all the mirrors and lens are clean and the right focal distance is set.
greetings
waltfl

Deane Donaghy
08-10-2014, 7:48 AM
I have a converted 40W machine with DSP AWC608 and I cut 3mm leather with 8mm/s speed and 40% power clean cut.
check your focal distance and the optic if all the mirrors and lens are clean and the right focal distance is set.
greetings
waltfl

Thanks I will check the mirrors and lenses are all clean, but I have always had problems cutting just about anything that has any sort of thickness.
It has no problem engraving most materials as I usually do granite and wood, and now some leather if I can perfect my technique.
Being a chinese laser the user manual is useless and the control software not much use either without decent instructions, so it is a self taught experience
so far but that is what I expected for the cost savings.

Bert Kemp
08-10-2014, 6:07 PM
My 40 FSL when it was working cut 7 and 8 oz veg tan no problem at about 60 pwr and 100 speed. Now oiled sides were another animal all together, I would have to make multiple passes at 100 pwr and slower speeds.

Kevin Gregerson
08-11-2014, 12:31 PM
Did some custom Leather products at .24 inch thick that came through perfectly as an application test for a customer on a Universal Laser VLS 3.50 with a 50 watt recently. When we got into some custom vinyl materials it had some melting issues which we were able to clear it up by messing with the pulse control settings. Cheap little machine that produces great results for the money. Have seen them still running and pushing out 50+ watts even 5-7 years later with almost zero maintenance.

Matt McCoy
08-11-2014, 2:35 PM
Kevin: Do you have set-up that is capable of cutting vinyl?

Bert Kemp
08-11-2014, 4:53 PM
Did some custom Leather products at .24 inch thick that came through perfectly as an application test for a customer on a Universal Laser VLS 3.50 with a 50 watt recently. When we got into some custom vinyl materials it had some melting issues which we were able to clear it up by messing with the pulse control settings. Cheap little machine that produces great results for the money. Have seen them still running and pushing out 50+ watts even 5-7 years later with almost zero maintenance.
Kevin could you put your equipment in your signature?

Kevin Gregerson
08-11-2014, 7:22 PM
Kevin: Do you have set-up that is capable of cutting vinyl?

Depends on the Vinyl mix. Many Vinyls are PVC so it's a matter of getting the MSDS to verify that it's not. Universal makes it pretty easy to get the settings right though. Like I've said on this forum before. I deal with service and sales and applications on Universal as a partner. The system I have in the office that I occasionally carry around for demo is the VLS 3.50 with a 50 watt and filter cart. The systems I service and play with range from 25 watt 20 year old systems to 150 watt dual laser setups.

Matt McCoy
08-11-2014, 9:41 PM
Cool -- thanks.

Kevin Gregerson
08-12-2014, 11:17 AM
Kevin could you put your equipment in your signature?

Better? I work on many types of ULS equipment old and new.