$150 Laser Cutter

[ScottyWarpNine]

Doubt black foam board would make any difference sine the foam itself is still white.

Are you able to get any cutting action in the foam? Could it be that it will take several passes at different focuses to get any decent penetration?

Curious to hear how the laser does on other materials like balsa, various papers, craft foam and such. Even if it can't get DTFB I'm still interested in this laser for my setup to use on balsa if it can handle that

It does seem to dig through the foam a little bit, but I wasn't sure if that was due to the laser actually cutting the foam, or from the heat put off from cutting the paper. I'm leaning towards the latter. Its actually quite interesting, when the laser is cutting something, the surrounding area isn't very bright, but as soon as it hits foam, the whole thing lights up like a lantern. It has to be that diffusion of light that prevents it from cutting.

Good news is it does seem to like cutting balsa, It takes a few passes, but it has burned straight through.

 

[jhitesma]

Yeah, that diffusion would do it. It's probably the structure of the actual foam in DTFB. May want to try some other foams, I've heard depron may work better. I bet it would also cut the craft foam that I use for battery padding and protecting boards on my multis.

Doing balsa is enough for me to want to put down the $50 for a laser. And start keeping my eyes open for an old scanner or two so I can build something a bit bigger than my current setup Has me tempted to try a few other wavelengths or a 405 from a non-ebay seller who backs the ratings on what he sells but charges more - Just the better lens may be enough to make a difference by changing the focus.

 

[TEAJR66]

jhitesma,

Could you use the carriage (or what ever it might be called) from an old plotter? If you had two, set up similar to the way you did the disk drives with the pen, would that cover a foam board sized area?

 

[ScottyWarpNine]

I still have a lot to think about. I definitely want to try other types of foam and other materials, but I would like to try to come up with a more scientific approach to test effectiveness of the laser than me pointing it at things. Like I mentioned earlier, I want to see how much current it is drawing as well as make some type of fixture to hold the laser steady and precisely relative to whatever I'm testing on. I've been pretty busy recently but now I have some free time to mess around with it.

I would also like to price out a 20-40W CO2 laser system and try to integrate support for that into my design as well, just in case somebody would rather spend a little extra on a CO2 system. For now I'm sticking with diodes though. I might try a few different Wavelength diodes. I think that may be the main limiting factor rather than power or focus. Since the foam is relatively translucent to the laser beam at this wavelength, the beam disperses and it won't cut. At least that's how it seems to me. That is why a CO2 laser works with this foam if I'm not mistaken.

If anybody has experience with lasery things I would appreciate any insight you may have on the matter.

 

[jhitesma]

jhitesma,

Could you use the carriage (or what ever it might be called) from an old plotter? If you had two, set up similar to the way you did the disk drives with the pen, would that cover a foam board sized area?

Yep. Or two scanners or printers. As long as they used stepper motors for their positioning they're fairly easy to re-purpose.

 

[jhitesma]

I still have a lot to think about. I definitely want to try other types of foam and other materials, but I would like to try to come up with a more scientific approach to test effectiveness of the laser than me pointing it at things. Like I mentioned earlier, I want to see how much current it is drawing as well as make some type of fixture to hold the laser steady and precisely relative to whatever I'm testing on. I've been pretty busy recently but now I have some free time to mess around with it.

I'm still very interested in seeing it progress. Even if it can't cut DTFB it's still a very useful tool. And you can always continue to experiment to see if you can find a way to cut DTFB.

I would also like to price out a 20-40W CO2 laser system and try to integrate support for that into my design as well, just in case somebody would rather spend a little extra on a CO2 system. For now I'm sticking with diodes though. I might try a few different Wavelength diodes. I think that may be the main limiting factor rather than power or focus. Since the foam is relatively translucent to the laser beam at this wavelength, the beam disperses and it won't cut. At least that's how it seems to me. That is why a CO2 laser works with this foam if I'm not mistaken.

If anybody has experience with lasery things I would appreciate any insight you may have on the matter.

I don't think wavelength is going to make a big difference. It would if this was a colored surface, in that case yeah, a different wavelength can make a big difference. But here, it's white. I think the issue is more that the structure of the foam is one that diffuses to effectively. All wavelengths are probably being diffused.

The CO2 laser works because it's MUCH higher power. And even then I hear it's tricky to get DTFB to cut well. (note how on FT's kits how much foam is missing around the cuts.) CO2 lasers also tend to make their power in the UV range so it's a much bigger change in wavelength - but makes things like focusing much trickier since you're no longer dealing with a visible beam.


I wouldn't be surprised if you could find some kind of combination of power, lens, wavelength and speed/passes that can cut DTFB...but the number of possible combos scares me from digging in trying

I would probably first get the laser mounted up to make testing more repeatable, then look into upgrading the optics and power supply on it to get better control/feedback

 

[mjcp]

...if this was a colored surface, in that case yeah, a different wavelength can make a big difference. But here, it's white.

I give you BLACK foamboard

Its a bit more expensive than the white foam board I use but if I could cut it with a home brew laser cutter, i'd pay...

mjcp

 

[RAM]

I still have a lot to think about. I definitely want to try other types of foam and other materials, but I would like to try to come up with a more scientific approach to test effectiveness of the laser than me pointing it at things. Like I mentioned earlier, I want to see how much current it is drawing as well as make some type of fixture to hold the laser steady and precisely relative to whatever I'm testing on. I've been pretty busy recently but now I have some free time to mess around with it.

I would also like to price out a 20-40W CO2 laser system and try to integrate support for that into my design as well, just in case somebody would rather spend a little extra on a CO2 system. For now I'm sticking with diodes though. I might try a few different Wavelength diodes. I think that may be the main limiting factor rather than power or focus. Since the foam is relatively translucent to the laser beam at this wavelength, the beam disperses and it won't cut. At least that's how it seems to me. That is why a CO2 laser works with this foam if I'm not mistaken.

If anybody has experience with lasery things I would appreciate any insight you may have on the matter.

At the very least you now have a laser etcher. Scale it up to the size of DTFB and you can "print" plans directly on the board with half the cut already made.

 

[paulshort]

I have been looking at GRBL. It is so simple to use if you have a way of generating g code. What i used was a pdf do DXF converter. I then opened the DXF in CAMBAM trial version and removed all the lines that I didnt want. I than made two toolpaths one for 50% cuts another for 100% cuts. I never actually built a machine because I built a 3D printer instead but I did get the software worked out. This is what I was going to use. It looks really good
http://www.aliexpress.com/item/free...ompatible-Pololu-A4988-driver/2044169337.html

You will also need some polulu stepper drivers.

Paul

 

[Hattrick]

A big plus on the PDF to DFX converter. A fair amount of work is required to clean up the DFX but a lot easier and more accurate than redrawing them. Then you can nest the parts and create toolpaths. I'm currently just using a pen holder to draw the plans onto the DTFB. The laser option is cool but of you can not cut completely through without melting the foam back to much it is just as easy to just cut it out with a nice fresh blade. I have a 4' x 4' CNC router so this is easy to do for me. Unfortunately the DTFB does not route well either. The foam melts and gums up the bit. I spent some time on google and could not find any information on successfully getting a nice clean cut on DTFB with a laser or a routing bit. I don't want to do my own experiments buying lasers to figure out what works either! Any information on successful cutting of DTFB with a laser or router would be greatly appreciated! I could supply DTFB with plans printed on, but I think the shipping costs would be excessive unless a number of them was shipped at once. So far I've only done the Bloody wonder as that is what we use in my club for combat. But I could easily do any plan available as a PDF.

 

[tyoho]

Milling DTFB

[ could not find any information on successfully getting a nice clean cut on DTFB with a laser or a routing bit. I don't want to do my own experiments buying lasers to figure out what works either! Any information on successful cutting of DTFB with a laser or router would be greatly appreciated!]

Do you have control of the spindle speed on your router? Try slowing it way down.
I am having pretty good results using an old CNC milling machine cutting DTFB.
Using a 1/16 dia carbide endmill at 3500 RPM and about 10 IPM. I've used a 1/32 and it works well also but the cutters
were a lot more expensive when you get that small with sufficient length of cut.

I know that normally that is wayyyy too slow a spindle speed for that size endmill, but it is the max sped for the
machine I'm using.

I'm getting a clean cut on the foam and even did some weight reduction pocketing leaving just a thin web of foam on the bottom.
It does fuzz the edge of the paper, but a few swipes with some 320 sandpaper knocks that off.

I tried a 40,000 RPM air spindle but got the melted foam you did.

For the score cuts I only go slightly deeper than the paper and manually follow that line with a knife later at assembly, the foam doesn't snap open to the milled lines, they are to wide.

You'll need to compensate for the cutter diameter in your program and clean out a few corners with a knife at assembly
but it beats cutting out by hand, specially the curvy parts.

 

[Tritium]

I give you BLACK foamboard

Its a bit more expensive than the white foam board I use but if I could cut it with a home brew laser cutter, i'd pay...

mjcp

2W 808nM cuts the black nicely. Black is available at Hobby Lobby in the USA. (not the RC based Hobby Lobby). I have to do some more experimentation to get a clean cut though. I tried this by hand but will now mount the laser to my ShapeOko and see what I can do with speed of cut plus clean the cut up a bit as well.

Thurmond

 

[RichB]

I wonder if there is a way to make an actual cutting tool work. Perhaps a stepper to rotate an Xacto blade in a holder, then another one to set the depth...

Ugh I have so many other things to do!!!!

 

[tyoho]

Drag knife

I wonder if there is a way to make an actual cutting tool work. Perhaps a stepper to rotate an Xacto blade in a holder, then another one to set the depth...

Ugh I have so many other things to do!!!!

It's called a drag knife http://donektools.com/
Somewhere on FT there is another thread that talked in depth about it.

 

[RichB]

Drag knives can't cope with thicker materials and still make tight radius cuts.

I'm talking about a cutter that can be actively rotated

 

[RichB]

Drag knives can't cope with thicker materials and still make tight radius cuts.

I'm talking about a cutter that can be actively rotated

Cool. So by typing "drag knife vs. " into google, I discovered that this thing exists and it's called a "tangential cutter" which is a perfect name for it. . . Maybe I'll extract the steppers from this old printer I am about to throw out.

Wait, what am I doing on this thread?

New challenge spotted...
Obsessive geek drive engaging...

Stop! Disengage! I have four unfinished airframes in the garage!

Abort unlikely. Research mode has already begun...

Ugh. Okay, umm, think of something else.
Cast iron cooking!
Backyard chickens?
Amateur blacksmithing!
Wood turning!
3D Printers? No that's too close to CNC stuff.
Yeah, CNC stuff.. wait we're back to where we started!

Curse you, ScottyWarpNine!

 

[RAM]

not exactly on topic but an interesting cutting tool

 

[Hattrick]

Routing DTFB

Can you give me more information on the bit you are using? 2,3, or 4 flute? How much cutting surface? Where do you get them? I can only go down to 10,000 RPM but I can cut at 32 IPM.

Thanks for the reply!

[ could not find any information on successfully getting a nice clean cut on DTFB with a laser or a routing bit. I don't want to do my own experiments buying lasers to figure out what works either! Any information on successful cutting of DTFB with a laser or router would be greatly appreciated!]

Do you have control of the spindle speed on your router? Try slowing it way down.
I am having pretty good results using an old CNC milling machine cutting DTFB.
Using a 1/16 dia carbide endmill at 3500 RPM and about 10 IPM. I've used a 1/32 and it works well also but the cutters
were a lot more expensive when you get that small with sufficient length of cut.

I know that normally that is wayyyy too slow a spindle speed for that size endmill, but it is the max sped for the
machine I'm using.

I'm getting a clean cut on the foam and even did some weight reduction pocketing leaving just a thin web of foam on the bottom.
It does fuzz the edge of the paper, but a few swipes with some 320 sandpaper knocks that off.

I tried a 40,000 RPM air spindle but got the melted foam you did.

For the score cuts I only go slightly deeper than the paper and manually follow that line with a knife later at assembly, the foam doesn't snap open to the milled lines, they are to wide.

You'll need to compensate for the cutter diameter in your program and clean out a few corners with a knife at assembly
but it beats cutting out by hand, specially the curvy parts.

 

[ScottyWarpNine]

Wait, what am I doing on this thread?

New challenge spotted...
Obsessive geek drive engaging...

Stop! Disengage! I have four unfinished airframes in the garage!

Curse you, ScottyWarpNine!

Overload! somebody needs to unplug RichB and reboot.

I'm starting to lean towards using a drag knife for foam board while still allowing the laser to be mounted for cutting balsa. Tonight I'm actually gonna start designing 3D parts so I can put some kind of a prototype together to show you. I know I haven't been contributing a whole lot to back up my big huge claim at the beginning...

 

[TEAJR66]

Would this motor and or board be any use in a project like this. I am an electronics idiot and everything on this board is greek to me. The motor has four wires and I thought three was the devils work.

I pulled these out of an HP printer. After starting this thread, I have had a desire to tinker with steppers and their controllers. I am in a target rich environment for such finds, so I have had my eyes peeled.

Motor Part Number: M55SP-2K LF
HP Part Number: RK2-2651

Board Part Number: RM1-5958
HP Part Number: RK2-2618