Dan Maloney
i vent ours outside , since it has a lot of contaminants in it
Probably with some filler in the rubber.
co2, fibre, all of them outside you can do it into an active carbon filter as well to help, but its a lot of gas and very small particulate
would bubbling through water do the job instead of a filter?
World's worst hookah
it'd need a lot of flow, but maybe, waterjets do use the water to help with that too, so its feasible, but there is still the gas depending on what you're cutting
Hey @Jonathan Schwartz - we're past an hour now. Want to keep going or wrap it up?
Aliexpress has some sweet-looking "80 watt" 450nm lasers. How much should I trust the offer? (Assuming incoming power instead of optical.)
they are reportedly combining power from two diodes.
it may have multiple chips and beam combining in-module.
I had good experiences with thin white material cutting when the line was dyed yellow.
Thank you!
makes a lot more sense when you're watching the youtube too heh
another trick, engraving polyolefins. paint the engraving areas (text) with a black pen, then scan with defocused blue laser.
translucent material ignores the beam, paint heats and bakes into surface.
TRICKS! Do tell do tell do tell!!!
the trick was to make sure text on polypropylene bottles of solvents won't wash off.
Any interesting fails? My one was trying to use nascent iodine generated from laser decomposition of iodoform, to etch copper on circuitboards. The copper totally ignored the process and everything stank like an old hospital for DAYS.
colour is interesting, we managed once to make repeatable colour with our mopa but never again.
logical. focal point on surface vs in the middle of the material thickness.
its very sensitive to temperature
thought. selective surface melting. coat a surface with a powder, eg. plastic or solder, and then raster/trace over.
which is a big issue with fibres and metal, the work area heats up and changes the cut properties. so much easier with co2 wood/plastic
then brush off the unmelted powder.
you can also engrave atypical stuff. I had success with sugar candy.
i like making keychains :)
what about a 5-axis head for the laser? engraving non-flat objects?
carbon steel
yes
3/16th
in the garage
LA
sure , i'm in northridge
that's a SWEET machine!
https://www.improwis.com/projects/food_LaserEngravedCandy/
Laser engraved candy
Because, why not? Does everything need a justification? This was the inspiration: Bittersweets, the despair.com Valentine candies A 40W CO2 K40-III laser cutter was employed. A test image ("test" text) was used for the engraving. The candy used are the kind consisting of pressed sugar, with some added starch, citric acid, flavorings and dyes.
1kW fibre
could it be done via 3d-scanning the object, then autogenerating the paths of the 5-axis thing to deliver beam perpendicularly to the object where desired?
sure, we are usually hanging out saturdays and doing stuff
g-code is the easy part. gcode is nothing but positions of the machine. a bit of math. brain-melting math at times but still just math.
you can laser weld too
3d gcode (and multiaxis) can get crazy. i never got beyond 2.5d yet, and failed to understand CAM software correctly so mostly just generating the toolpaths in python.
do you mean the 3d capture obama project?
ahh ok, i meant this one https://www.bbc.com/news/av/world-us-canada-30306967
femtosecond lasers are fun too. any knowledge of them?
or the copper-vapor ones?
would love to get a femtosecond
short pulsed lasers can vaporize material before the underlying layers can even notice something is happening.
@Jonathan Schwartz - thanks so much for your time today, this was really helpful. And thanks to everyone for the great questions!
FYI, I'll post a transcript in a few minutes, along with a link to the YT video. Thanks all!
thanks a lot!
Jonathan, I joined late but the info you shared was very useful, I will be rewatching this one.
also you can cut biomaterials. lasers are used in medicine.
co2 as a scalpel. got hand in a beam, and it healed nicely.
so neat
yup, tattoo removal lasers can be used for welding if the q-switch gets removed.
cheers
cheers!!
yeah ebay cheap tattoo removal lasers :)
stryropyro style
lasers don't care what they are used for. if you do not tell the tube it is for medical uses, it will happily deliver its scalpel-cauter like work.
blue laser works too, though I am a wimp and tried it only on a piece of ham instead of myself. (the CO2 test was accident.)
...should try melting acrylic powder (eg. the nail-art material) into surface of clear acrylic.
...or cocoa powder into white chocolate.
heh
food shenanigans have the advantage that you can easily dispose of the fails. (and the successes too.)
i wonder if i can slice pizza
wisconsin uni tried to cut cheese. turned out you need a uv laser for good cut, without melting more than cutting.
lasercut pizza will be on youtube. i think i saw it.
yeah its amazing how many folks think, laser, food lets try it .. our hackerspace had many varied smells
the fat
how much cooling does the kilowatt machine need? how big/heavy it is?
it has a dedicated water color fan thing thats a decent size
i ahve some pics somewhere i think
a water chiller?
https://gweikecnc.com/product/107.html its a gweike, who pretty much supply most everyone these days
yeah it runs water to the head
and relative size
sweetie!
the two tanks were the best we could get on a saturday of n2/o2 persuaded a local brewery supply shop to sell us them, but replaced them with much larger ones
saw the oxygen separator zeolite beads on aliexpress. for pressure-swing separation.
could work for both oxygen generation and nitrogen-enriched stream.
yeah the o2 is very low pressure so that tank we've had since the start, the n2 though you go thru like crazy
pressurize some air, then cycle compression-decompression through cylinders with the zeolite.
electrochemical medical oxygen sensors can be bought (annoyingly expensive) too. going up to 100% o2.
n2 runs about 12 bar
what is its role in the process? mechanical blowing off stuff from the cut?
yeah we looked at medical ones, but the pressure and the amount they generate per cost, i think it was about 5K USD for one that makes a very small amount, so going with the rotary compressor with a fridge/dryer setup
for o2 it helps it burn, the n2 shields
so deeper cuts/nice cuts
there are also industrial ones. same principle, bigger size, no medical nonsense paperwork/certs/price.
yeah iirc the issue was the pressure
flow speed? as the pressure converts to speed in the nozzle?
we found a chinese compressor for 4K new that can run upto like 25 bar
not bad!
tank pressure, since for the n2 upto a 3mm nozzle with 12 bar
so a 300 tank lasts maybe 12-15 minutes and thats around what 140 bar?
there are also membrane-based nitrogen separators.
yeah we looked at a whole range of medical supply ones, they just didnt generate anywhere near enough for the cost,since medical
a pair or three medical oxygen generators is sometimes used as alternative to bottled oxygen for smaller-scale glassworking.
like terra https://www.terrauniversal.com/portable-nitrogen-generator-2700-99.html
we had a big-ass generator for gas assist in a plastic moulding factory.
so like 6 scfh
yeah this is what we bought
like with an electric car battery, you could have a nitrogen production unit running 24/7 and feeding a tank and taking out of the tank as needed at higher flow than the generator would give.
three phase, 15HP, just have to find a place to put it
a second floor of the garage. :P
or a basement under the garage.
i think its going outside in the garden heh, no basements here
bad geology?
yeah northridge, earthquakes, liquefaction zone
yuck.
yeah you know its bad when you live in a place that has a quake named for it
fun! get shakin'!
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