7.3 Watt cutting metal

[Yoshi1988]

Here is my newest laser. This one is a 450nm 7300mw.
Here's a little video of it cutting a metal spring.

 

[CaliKirk]

Niice! That's definitely some raw power right there!! What diode are you using and what current setting? I wonder how your laser would perform up against something like 1/4" steel?

 

[Pman]

Not a chance with 1/4" steel. Cool vid though. Funny that the next vid that loaded was a Styropyro of the laser I had just bought from him. Has a 3W 9mm in it but right after I tried it the driver blew so I just ordered another one. Doesn't matter as he sold it as a host as it's a beaut. Osirus.

 

[CaliKirk]

What's the thickest sheet of steel that 7 watts would go through you think? It doesn't have to be like butter but I know I've seen a video somewhere of a guy burning through what looked to me like a 1/16" sheet of steel but could have been thinner. Either way it's insane to think of how much power can be had with all the new diodes coming out.

 

[RedCowboy]

If you can burn a hole through a 1/16 thick sheet of steel with the 7w blue laser I will drop my pants and fire off a rocket.

 

[Yoshi1988]

1/4 inch of steel is asking a bit much even from this behemoth lol.

 

[CaliKirk]

Im pretty sure it wasn't a 7w laser that was cutting through steel. Keep your pants on red! The way i worded it was wrong or really incomplete, the video I saw was I believe an array from an m140 projector, but who knows could have been a custom setup. I was more wondering what something at the 7w level was able to damage to a sheet of steel? Just heat it up?

 

[Yoshi1988]

This laser won't go thought a 1/16 inch of steel... I just tried.. It heats up red hot but that is about all.. Not that I was expecting anything differnt lol.

 

[Pman]

Anyone have a way of measuring how hot the dot gets?

 

[Yoshi1988]

Yeah it's called a lpm lol

 

[Benm]

Impressive how quickly that spring goes into two bits!

Chopping through a sheet of metal is a lot more difficult though. The spring breaks apart as soon as you melt a piece of it, gravity pushes the two halves apart.

In a sheet there is no such thing, even it you manage to actually melt it, it will just solidify back when you remove the laser. It may look tarnished or otherwise affected, but there will be no hole.

This is vastly different from cutting slots into materials like plastic or wood, since those are not thermally conductive, and they also melt away instead of staying in place if only a small bit is molten.

To cut slots in metal you need it so hot it locally evaporates, and quickly enough so that the surrounding metal doesn't melt and fill in the material evaporating. Heat conductivity is also important here - you may find it easier to cut a hole through steel than through aluminium, despite the latter having a relatively low melting point.

 

[Yoshi1988]

What Benm said

 

[Chrisbee]

Yeah, if you wanted to try and cut sheet metal with it, you'd have to set it up like a plasma cutter. Get it red hot, then push compressed air at it to blow throw the metal. Plasma cutters just do that really fast. Without the compressed air, it be more like welding. As far as measuring the temp at the hot part of the steel, Harbor Freight has some relatively inexpensive pistol type temp probes.

 

[Benm]

I suppose you don't really need to blow away the molten material when using a laser, as at some point it will start to evaporate and that boiling will take some molten material with it.

For materials as thick as 1/4 inch this will probably not work, but you could possibly cut shapes out of thin metal sheet (0.1 mm or so). If you do this it is best to have the material suspended though: if it's resting on some sort of flat base chances are most of it will melt and re-solidify exactly where it was.

Welding would also be an interesting application though: Perhaps you could weld fairly thin work items using a laser, things that would be too delicate to approach with any kind of torch that would blast it away even with only the combustion gasses and no intentional pressure. I'm not sure what a practical application would be right now, but the idea is interesting.

 

[Rivem]

I suppose you don't really need to blow away the molten material when using a laser, as at some point it will start to evaporate and that boiling will take some molten material with it.

For materials as thick as 1/4 inch this will probably not work, but you could possibly cut shapes out of thin metal sheet (0.1 mm or so). If you do this it is best to have the material suspended though: if it's resting on some sort of flat base chances are most of it will melt and re-solidify exactly where it was.

Welding would also be an interesting application though: Perhaps you could weld fairly thin work items using a laser, things that would be too delicate to approach with any kind of torch that would blast it away even with only the combustion gasses and no intentional pressure. I'm not sure what a practical application would be right now, but the idea is interesting.

I've seen laser microwelding and soldering stations before. Not sure of the power or diodes they used, but I want to say that they did use diode banks.

 

[Pman]

I have a few non-contact IR meters including a nice Fluke one so I may try it sometime. It looks like it goes up to 1022F and it has to get way hotter than that. I'm pretty sure paper burns at 451F or at least that's what Ray Bradbury says
One interesting metal is Magnesium which has a boiling point of 1994 vs. A melting point of 1202F