Expensive laser cutters have a 3D engraving mode that varies the laser power as it is etching a design, to create a 3D effect. [Benjamin Alderson] figured this could be replicated on a cheap Chinese laser — so he made his own program called SmoothCarve.
He’s got one of those extra cheap blue-box 40W CO2 lasers you can nab off eBay for around $600-$800, but he’s replaced the control board with a SmoothieBoard as an easy upgrade. He wrote the program in MatLab to analyze a grey scale image and then assign power levels to the different shades of grey. You can see the software and try it yourself over at his GitHub.
The resulting application is pretty handy — watch it carve the Jolly RancherWrencher after the break!
In case you didn’t know, the SmoothieBoard is the Be-All, End-All CNC Controller — it’s almost three years old now since it launched on Kickstarter!
“watch it carve the Jolly Rancher after the break!”
oh man, i haven’t had a Jolly Rancher in like forever! i however was dismayed to see it instead carving the Jolly Wrencher
lol
Stupid autocorrect…
I have all of the 80/20 I need to build a laser. I want to build a 60 watt one based on Bart Dring’s design over at buildlog.net but I am so tempted to get one of those chinese burners just to get my hands dirty….
I did exactly that, thinking it would become a PSU and tube donor. Still using it – with different electronics (now a Smoothieboard) of course.
That’s what I did. Bought a k40 “40watt” for $366 shipped last December. Cheap enough to hack/modify and learn about laser cutting. Already have the 80/20, linear rails and servo motors to make a larger X/Y table similar to Buildlog. Will move over the CO2 tube, PS and mirrors to new machine when complete. Cheapest way to have a laser cutter at home.
I’d recommend new mirror mounts (which normally means new mirrors, sadly) as aligning the k40 is a horrible task.
30 mins to align. BUt $366 is not what k40’s go for. More like $599. Maybe $566 if you’re lucky?
Nope got mine from eBay $366 total price shipped fedex from CA. I guess they went up in price from last Nov/Dec. There were atleast 5 buy it now listings for $366 with free shipping.
I just checked eBay again. There are several listings for $366 + $20 shipping. Mine was free shipping in December.
This is awesome! If you’re ever interested in creating those gray scale images from STLs, give this a shot.
http://wiki.paxspace.org/index.php?title=CNC_Router#3D
Its using Blender and a simple node tree to render any 3d object (import stls without issue) into a 2d grayscale heightmap!
That’s a very useful looking link – that’s next on my todo list. The vast majority of 3D experience I have is in 3D CAD, not artistic modelling, so I need to do a lot of work to learn how to think in a totally different way. Got a couple of other projects to work on first, but hopefully going to be able to integrate carving directly in the Smoothie firmware in the next 3-6 months or so.
Blender will load any STL. So you can continue using your 3D CAD program, export the file (as an STL) and import it into blender to get your heightmap.
*Wrencher != Rancher
Wrencher ≈ Rancher, it’s quite a good approximation to the real value.
Jolly Wrencher on a Jolly Rancher = Jolly wRancher.
https://www.instagram.com/p/BCjpJaxkUD4/
(It was CNC engraved not laser cut)
This approach also works somewhat with 2W M140’s but you still have to be careful because you don’t want to drop it below the lasing threshold. If I recall my laser physics correctly with a tube the output power is a function of bore current and heater power but you always run it at >x amps to prevent destructive erosion.
Essentially the plasma becomes unstable and wanders where it is not wanted and can eventually cause the laser to fail due to the formation of unwanted conduction pathways: this is also a common failure mode in HeNes.
source: Sam’s Laser FAQ
Also losing coolant while lasing is very bad indeed. I’d also add a coolant temperature and pressure sensor (a simple chamber with a BMP085 and rigid airtight pressurizable casing, pretty sure it can be 3-D printed to fix existing pipework)
I also heard that there can be issues with some tube replacements that are similar electrically but not mechanically, its well worth asking around if anyone has a “bad” or low power tube just to keep around for those times it decides to fail in the middle of something important.
I use this approach with a lot of stuff now as its cheaper than having two of everything, got me out of trouble when a main drive failed on one of my machines. 120GB is better than no drive at all.
A Barometric pressure sensor is normally not suitable for checking coolant pressure. It is an absolute pressure sensor while you want a relative pressure sensor (relative to ambient) for the coolant pressure. Often the range does also not fit.
This is very nice! I hope to do some similar work with a router in the future.
“He’s got one of those extra cheap blue-box 40W CO2 lasers you can nab off eBay for around $600-$800”
They’re a hell of a lot cheaper than that these days, like the Chinese clones of the MakerBot Replicator 3D printer they just keep getting cheaper and cheaper. Back in October-November or thereabouts, I picked up one of these K40 lasers for $380… (Though mine didn’t come with an air assist or the internal lighting. I’m adding those.) I definitely need to get a Smoothieboard for mine, that carving is great.