Foam Cutting Minimum Power

Full Disclosure: I am most definitely a newbie at all of this.

I am trying to assemble a laser that is capable of rapidly cutting through styrofoam, about the thickness of a disposable styrofoam dinner plate. The foam will be dark blue/black in the areas that will be cut.

I was able to order an 808nm 300mW diode off ebay for about $3, but after browsing these forums it seems as if this is an unsafe wavelength for beginners so I plan on avoiding this for the time being.

What do you think the minimum power is for me to cut through styrofoam of this thickness? What wavelength do you think is best to accomplish this?

If there is another thread which has a tutorial on how to build a laser assembly of this kind (which diodes, what drivers and how to put it all together), I would greatly appreciate a link to it.

Not a single person can help me out with this?

How about you wait longer for a response? Not everyone cuts foam on here...

You'll need more the 300mW to rapidly cut even thin foam.

It's not so much that 808nM is unsafe, its the fact that it is invisible to the eye.

To be safe you would want the laser enclosed in something that prevents reflections from hitting your eye.

1W of 808 should be able to cut thin foam at a reasonable rate, but you would also need some sort of ventilation to prevent your optics from being contaminated from the vapors.

I'm a noob too, and I asked the same question a few months back, but with thicker foam for making Halloween tombstones and the like.

General consensus seemed that even 1 W. of 808nM wouldn't be enough for 1" thick foam to be cut at any worthwhile pace...

As indicated above, safety is critical with invisible wavelengths.

Personally, I chose to stick with X-acto knives, hotwires, and soldering irons.

What really is the point of even using a laser to cut Styrofoam? It's not like you need precision cutting capability that a pair of scissors or an Xacto blade couldn't do better and faster.

automation... for starters.

set up a piece of foam and go eat dinner and watch a movie, while your item is made for you.

also would increase precision as well as allowing for cuts and shading that would be otherwise impossible.

GoolGaul said:

automation... for starters.

set up a piece of foam and go eat dinner and watch a movie, while your item is made for you.

also would increase precision as well as allowing for cuts and shading that would be otherwise impossible.

Click to expand...

That is exactly what I am thinking - a cool science fair project for middle school or high school kids. Considering the thickness (roughly 7-10 pieces of computer paper) and the low density of the foam, would I really need a 1W laser?

Assuming the foam is traced with black ink along the shape to be cut out, Do you think an old 16x (or higher) DVDRW laser work? I am not looking for something so powerful that it will cut through it instantaneously, but maybe after 2 slow passes with the laser it would be deeply scored to the point that the cut design could be "popped out".

I am looking for the cheapest way possible to do this. I can build my own LM317 (as well as an Arduino if that has any use here) but some direction as to where I can get the right laser diode, matching lens and heat sink would really be appreciated (sorry, I really do need my hand held to get through this project!).

One final thing: the laser diode will only be about .1 or .25 inches away from the foam if that makes a difference. Do I still need a lens at this range?

GoolGaul said:

automation... for starters.

set up a piece of foam and go eat dinner and watch a movie, while your item is made for you.

also would increase precision as well as allowing for cuts and shading that would be otherwise impossible.

Click to expand...

You don't need a laser for Syrofoam cutting automation, and if it's going to take a whole dinner and watching a movie, I really wonder what you're even gaining? And really, laser precision on Styrofoam? The foam bubbles themselves are large enough that you don't need a laser for that kind of precision. It'd probably melt up anyway. Get a spinning drill for something like that.

Bionic-Badger said:

You don't need a laser for Syrofoam cutting automation, and if it's going to take a whole dinner and watching a movie, I really wonder what you're even gaining? And really, laser precision on Styrofoam? The foam bubbles themselves are large enough that you don't need a laser for that kind of precision. It'd probably melt up anyway. Get a spinning drill for something like that.

Click to expand...

I think the time frame was just to make a point, and automation was just an example, this setup will be used in a project aimed at middle/high school science classrooms. This will not be used for carving a sculpture from a single block of foam, but rather thin sheets of foam that will be cut from disposable styrofoam dinner plates.

Melting is a potential issue, I agree, but I will cross that bridge when I get there. Right now i'm still hoping for some help with the proof of principle/initial design. As always, any tips would be appreciated.

not using packing-style styro, but the insulation type. the blue/pink stuff. much denser, not "bally".

Sorry I didn't cite a suitable time frame for ya Bionic, and what I gain is dinner and a movie, and no hand cramps from wielding an x-acto for 4 hours...

The other problem you are going to have cutting Styrofoam is even with black markings once you burn thru the black or blue line it is white underneath. All you will get is a toxic smoke, I know some one that has a 45 W laser cutter an has cut plastic, but the smoke is toxic and it melts the plastic.

I do some work at a plastics manufacture and they do not use lasers to cut the plastic, they use a robotic knife or a dremell to cut the plastic while it is warm.

1W 445nm should be fine for what you are doing. You can focus the beam nice and small, and it can cut white objects if focused properly.

If you do that make sure you have adequate ventilation since the smoke off of styrofoam or polystyrene is very toxic.

After speaking with some members and considering the specifics of this project, I decided to go ahead and build the laser loosely based off this website: Build a Burning Red Laser from an Old PC | Hack N Mod. I plan on having both the laser from a DVD Burner and the IR diode that I mentioned before (808nM 300mW, 2.2V)

I ordered this Aixiz module (knockoff aixiz actually, for $3.99 I couldn't say no). I am going to pickup the parts later today to make the LM317 driver that is featured in the post accompanying the above link (http://laserpointerforums.com/f42/diy-homemade-laser-diode-driver-26339.html).

Here are some questions now that I have some of the basics down:

1. Will the acrylic lens included with this aixiz module melt with either of these diodes?

2. With regard to the LM317 I plan on using, the plans call for 2 AA batteries producing 6V (unsure of the current). The instructions say to go at least 3V above what the diode is rated for. What are the specifications of the power supply that I would need to drive the diode at 250-300mW without blowing it out? Would it be best to just use an old PC power supply as is shown in the video?


In response to some of the concerns people have about ventilation and the danger of IR, I plan to operate this setup with negative pressure ventilation and fitted into an enclosure to minimize safety risks.

Thanks in advance