Cutting depth and power

[James80]

I was wondering about cutting depth and power. My laser will cut at around 15amps.
It's a jsm40u, doesn't go very deep, I was checking out the hpclaser website looking through the similar models and was interested to see how the same 40watt tubes were quoted as cutting very differing depths, from 10mm LS3040 PRO Laser engraving and cutting machine [LS3040] - £2,450.00 : laser engraving machines laser cutting machines, HPC laser LTD to 20mm on the 6040pro.
I was under the impression it was purely related to the 40watts of tube.
These lasers have different size tables and water features, but there's no real indication of how the larger depth of cut is achieved.
I know you can get different lenses for them, but I wondered if there was a difference in the psu's and even software driver boards, that was making the difference.
I'd rather upgrade the right part, than the wrong one.

[pontiacg5]

40 Watts is a measure of power, 40 watts is equal to 40 watts and no power supply or controller will change that. Laser power is measured as output from the tube, so the control or power supply might be different but the total power hitting the work material will be the same.

The only way to change cut depth without a stronger tube is a balanced combination of cut speed, air blast pressure, and focal length.

My guess, they are stretching the truth in one place or another.

[keebler303]

James

What you are seeing is "marketing strategies". If you assume the same beam quality, the same optics and same speed, you will get the same cut. You have to be careful about what a company says the laser will cut (at super slow speed and terrible edge quality). One of the best things you can do is find or create some simple file similar to what you want to make, send that to multiple companies and tell them to run it on the machine you are looking at and send it back. If they won't do that I'd cross them off the list.

Matt

[James80]

What you guys say makes perfect sense. I did have a look at DIY building a laser cutter where they suggest neon sign power supplies, and different supplies can give different results.

So does air blast make a difference? Like plasma cutting requires air. Indeed, I read up on the lasers before I bought mine 3 years ago. I just wondered about making serious changes. I'm not cutting through 1/8" mdf with 40watts, 5mm/s and 90% power.
I nailed through softwood, and I reckoned I have left that for 2 weeks. It would be hideously dry and explode under pressure of automatic centres on our rotary lathes.
Dust plant feed stuff.
Hmm.
I might ask

[Exsecratio]

I'm with Ponti and Matt James, as the theory goes you can cut 20mm acrylic with a 40 watt laser (if you do 3 or 4 very slow passes) but in the real world the edge, as the guys have said, will be crap and it will take a week

Your speeds do seem a bit slow, I'd be looking for 14 mm per second at 75% power with your set up. Check the alignment and top surface of your final lens for crud...another consideration is what type of MDF? if it's the nasty B&Q stuff then don't bother, it's ****e and gives off some pretty nasty fumes.

You need to use Medite (a dedicated laser MDF type)

Air assist is God, no two ways about it, I use a modified aircone on mine and have an acrylic end that is running 1.5mm hole and 5psi of air from a silent type Clarke compressor. Phil Davis came up with the aircone idea and afaik he sells them retail at a resonable price. have a look HERE

best wishes

Dave

[James80]

I see. Didn't know about the mdf. The air nozzle stuff sounds interesting. I've registered to see the pics.
What sort of air supply is needed, I have several compressor options, but obviously there kept miles from the laser.
Thanks