Benbox Laser Machines/CO2 Lasers/3D Printers

General Category => Cutting => Topic started by: marche247 on December 08, 2016, 05:32:19 AM

Title: Cutting foam board
Post by: marche247 on December 08, 2016, 05:32:19 AM
I really wanna be able to cut foam board with my desktop chinese laser .

Would multiple passes work?
Is there a different free software i could use?
Is that even a possibility?
Title: Re: Cutting foam board
Post by: Zax on December 08, 2016, 05:37:09 AM
Software isn't the issue, it's a combination of the laser power and lens.
Title: Re: Cutting foam board
Post by: marche247 on December 08, 2016, 05:40:22 AM
Is there any type of modification i could use maybe?
Title: Re: Cutting foam board
Post by: Zax on December 08, 2016, 05:49:06 AM
There's probably not much you can do with your laser, my 40W CO2 cuts it cleanly at high speed (both sides) sitting on a honeycomb bed.

If you get foam board with dark layers it may work, I have some that's black but the inside foam is still white which reflect the diode wavelength and doesn't absorb the energy.
Title: Re: Cutting foam board
Post by: Lob0426 on December 08, 2016, 10:48:02 AM
The blue diodes are the wrong wavelength to cut the foam. I think you would have to get a blue diode at very high power to cut the foam. There are no diodes at that level available to us at this time.
Title: Re: Cutting foam board
Post by: wild.bill on December 08, 2016, 03:05:05 PM
I have tried the black foam board and the only difference is you get a lot of burnt black paper on the top.
Title: Re: Cutting foam board
Post by: Lob0426 on December 08, 2016, 03:32:59 PM
I tried the newer "waterproof" board with about the same results as the white or black.

I have a 1W 850nm diode I am going to test on the foam board. I hope its wavelength will be more successful. I probably will not be able to try it out until the holidays are over.
Title: Re: Cutting foam board
Post by: Nick-Nitro on December 27, 2016, 02:17:31 PM
i want to try with mi violet laser, 2.5W 445nm if i can cut it... hoping so
Title: Re: Cutting foam board
Post by: Administrator on January 14, 2017, 01:58:26 PM
I just tried...using a 1.6w laser, speed mm 100, 100% power...12 passes I can get about 80% through but not all the way.
Title: Re: Cutting foam board
Post by: wild.bill on January 14, 2017, 02:38:23 PM
I just tried...using a 1.6w laser, speed mm 100, 100% power...12 passes I can get about 80% through but not all the way.
The way I cut this foam is one pass with the laser, and the second pass is with the X-acto knife. The only way I have seen that works every time.
Title: Re: Cutting foam board
Post by: Zax on January 14, 2017, 04:13:28 PM
What you need for this stuff is a tangential knife plotter (the flatbed kind). Some of the better vinyl cutters still use this setup rather than the cheaper drag knife configuration. They're excellent for cutting thick rubber mask used in stone and marble engraving.
Title: Re: Cutting foam board
Post by: mightygrom on September 27, 2018, 11:28:28 PM
The way I cut this foam is one pass with the laser, and the second pass is with the X-acto knife. The only way I have seen that works every time.


what settings are you using for the scoring cut?
Title: Re: Cutting foam board
Post by: ggallant571 on September 28, 2018, 06:23:45 AM
I suspect it also depends on the color. Black is probably easier to burn than white but I have not tried either.
Title: Re: Cutting foam board
Post by: pedwards2932 on September 28, 2018, 12:46:56 PM
Has anyone tried the blue insulation foam?  I have a hot wire cutter to make it in sheets of any thickness.  It is blue thru and thru so maybe it would work.  When I get a chance I'll try it.
Title: Re: Cutting foam board
Post by: ggallant571 on September 28, 2018, 12:57:37 PM
I think the blue laser will have little effect on blue foam board. I use brown masking tape when I want it to be cut and blue when I don't.
Title: Re: Cutting foam board
Post by: pedwards2932 on September 28, 2018, 01:03:21 PM
How about pink?  I got some foam sections at home depot that are pink....
Title: Re: Cutting foam board
Post by: Zax on September 28, 2018, 04:09:07 PM
I wasn't able to cut that with either diode or CO2, in the end I used a hot wire cutter - which worked but very slowly. It does best on white expanded polystyrene.
Title: Re: Cutting foam board
Post by: ggallant571 on September 28, 2018, 06:47:44 PM
I saw a project video last week that used the same motion technology we have with laser diode machines to make a 4-axis hot wire foam board cutter. It was geared towards making complex wing parts for model airplanes.
Title: Re: Cutting foam board
Post by: RobOlsen3 on October 01, 2018, 09:37:15 AM
I cut the pink styrofoam from Home Depot (outdoors - fumes) to throw together quick cheap boxes and speaker enclosures with NO sawdust. I need several passes at high speed to get a relatively clean cut; the hot combustion gases tend to further erode and scallop the cut edges.  I use Fusion360 to make the cut patterns, including tab-and-slot features to interlock the panels, and generate the gcode. Assembly uses either Glidden Gripper primer or expanding polyurethane foam (Great Stuff) as adhesive; the Gripper is neater but takes forever to cure, the Great Stuff cures quicker but gets EVERYWHERE.  I usually clamp with either packing tape or cling wrap film. Gorilla Glue would probably work really well, too.

I also cut foam core with my 2.5W; I bought a 10 pack of Elmer's 20" x 30" black on black from Amazon, but I've seen B on B at Michael's around here when I was picking up slate coasters.  I also bought a large piece of black-on-black at Office Depot or Staples or some such, and it all cuts really easily.  Nothing with white inner foam cuts worth a <bad word>.

3/4" pink styro tabbed and glued like this is unexpectedly strong, especially for the weight.
--Rob
Title: Re: Cutting foam board
Post by: Zax on October 01, 2018, 11:33:19 AM
@RobOlsen3 You were able to cut the 3/4" pink styrofoam with a 2.5W laser?

I must know how, did you do anything special, I tried with various methods and couldn't get a good cut.
Title: Re: Cutting foam board
Post by: RobOlsen3 on October 01, 2018, 02:53:45 PM
Yes, pink Foamular styrofoam from HD, both 3/4" and 1".

Perhaps my standards for acceptable cuts are less exacting? 

Let's see here - looks like this file has a lot of F800 in it, probably cutting feed rate, and some F2000 which I imagine is rapid movement feed rate.I also appear to have baked 10 passes in, but I don't think it needed that many.

Looks like 6-8 passes at 800mm/min should do it.  I've cut with the peel-off "skin" in place and removed, doesn't seem to care.  Passes through, doesn't seem to stop the cut.

I set the laser focus to be fairly far from the lens, for a shallower angle and greater depth of field - this keeps the beam narrow over a longer cut depth. I then set the focus for about halfway through the material; setting the focus on top means it is pretty diffuse by the time it gets to the bottom of the cut.  I am not adjusting work height or focus distance between passes.  I think air assist is critical here, the combustion gasses from the cutting process expand within the kerf but the foam is so low-mass that the gasses eat into the edges of the cut, hence the scalloping.  So strong airflow really helps here, I think.

I have some videos somewhere. I should post some closeups of the fingerjointing so you can see the edge quality.
Title: Re: Cutting foam board
Post by: Zax on October 01, 2018, 05:27:46 PM
Well that doesn't sound too difficult, I will give it another try with air assist turned up. I may not have used that last time. Thanks!