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This is actually v2 of the exhaust, v1 (which I knew would need to be replaced) was the exhaust fan that comes with it blowing into a 20 foot dryer hose which blew into the stupid blue tube that came with the machine that was duct taped to the dryer vent I'd installed (because the dryer vent pipe was flush with the wall I couldn't get the dryer hose to plug into the pipe, I needed an intermediary, and the blue pipe was there). Gotta cut cut cut! The built in exhaust vent looked like it could blow more air than the inline one I have now (by comparing how far out the flaps in my dryer vent are pushed when they're on) but this new solution is much more air tight. I was cutting some cardboard to test my modifications and even just having the dryer hose sitting by the exhaust hole (all 20 feet of it) it already smelled better than previous attempts cutting paper with the exhaust fan it comes with.
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Feb 29, 2016 19:42
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Could masking tape also prevent stray reflections? That's my theory.
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Feb 29, 2016 21:51
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Glass is opaque to the radiation used so there should be no reflections to speak of  Nothing like a good test. I should try engraving on the flat side of an old mason jar or something. Do a couple with different setups and see what happens.
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Feb 29, 2016 22:30
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I did a few experiments a couple years ago. The mode of glass being etched looks like the glass heating up quickly in a very localised spot and then chipping off. My tests without masking tape looked like they had a much larger (read: much blurrier) etch area. Your lines look way better than mine ever did.
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Mar 1, 2016 01:16
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So that little fan that blows are out of the electronics area: I think it's weird that it blows air out while the exhaust is also trying to blow air out. I'm thinking of turning it around so it blows air into the machine and then the exhaust can pull it out. Does anybody else's fan blow air out rather than pull it in?
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Mar 5, 2016 20:26
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Installed a drag chain for the air assist last night, not sure if I want to attach it to the head anymore than it is or leave it like this. http://i.imgur.com/tmcM1MF.gifv
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Mar 8, 2016 19:18
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In exchange for helping her figure out the nitty gritty on the machine I am going to get near unlimited use of a smaller full-spectrum cutter. 
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Mar 17, 2016 01:35
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I scored some pretty nice scraps and off-cuts but I have no idea whether this is acrylic or polycarbonate. Any easy way to tell (besides trying to laser it)?
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Mar 31, 2016 17:34
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Mister Sinewave posted:I scored some pretty nice scraps and off-cuts but I have no idea whether this is acrylic or polycarbonate. Any easy way to tell (besides trying to laser it)? Acrylic will craze if you apply IPA. Not sure if polycarbonate crazes as well though.
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Mar 31, 2016 19:39
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Is that isopropyl alcohol? I didn't know that about acrylic. I could also see how readily it snaps / fractures I guess but some of these are 1/4 inch or 1/2 inch thick and I don't have a "feel" for them like I do for 1/8.
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Mar 31, 2016 19:51
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Mister Sinewave posted:Is that isopropyl alcohol? I didn't know that about acrylic. Yep. Some research tells me that polycarbonate does not craze when exposed to isopropyl alcohol, so if you have some scrap, that's one way to check.
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Mar 31, 2016 20:10
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Is the crazing something that is naked eye visible, or do I need magnification? I tested with a piece of acrylic and so far as I could tell all that happened was it got wet, then dried.
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Apr 1, 2016 01:59
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Hmm maybe acrylic cement doesn't work on polycarbonate and I could test with that. It might be easier to just test cut a small area. (Acrylic cuts clean but polycarbonate cuts dirty)
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Apr 1, 2016 02:01
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Maybe a week too late, but - I use 100% isopropyl to clean fingerprints and adhesive residue off my acrylic and polycarbonate pieces. Acetone, on the other hand, will have an immediate softening/clouding effect on both. Alcohol is, to the best of my (admittedly amateur) knowledge, safe to use of virtually any common plastics. In general, it's somewhat easy to differentiate between acrylic and polycarbonate solely by physical properties. Acrylic will scratch like glass and is quite stiff, even if it's a thin sheet. It will also shatter into sharp shards when impacted or broken. Polycarbonate tends to be softer and more flexible, and when you try to scratch it with something you usually see more of a soft surface deformity rather than a hard scratch. If you whack it with a hammer, you're likely to just dent it and then hurt yourself when the hammer bounces back at you.
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Apr 7, 2016 00:13
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Acid Reflux posted:Maybe a week too late, but - I use 100% isopropyl to clean fingerprints and adhesive residue off my acrylic and polycarbonate pieces. Acetone, on the other hand, will have an immediate softening/clouding effect on both. Alcohol is, to the best of my (admittedly amateur) knowledge, safe to use of virtually any common plastics. Interesting. The lab I work with forbids the use of IPA on acrylic because of some really bad crazing damage done to clear acrylic pieces. It could be a surface finish thing maybe? Not sure, but we want our stuff to be optically clear, so any crazing is a big issue.
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Apr 7, 2016 00:38
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IPA will craze acrylic over time. Happens to our old acrylic suction bins when we use alcohol disinfect wipes.
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Apr 7, 2016 00:49
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Dirk the Average posted:Interesting. The lab I work with forbids the use of IPA on acrylic because of some really bad crazing damage done to clear acrylic pieces. It could be a surface finish thing maybe? Not sure, but we want our stuff to be optically clear, so any crazing is a big issue. It may be something in the surface finish, or maybe the particular formulation of acrylic? The stuff folks usually run through a CNC or laser cutter is a cast sheet, and doesn't have any special properties other than being really easy to machine. I imagine (read: speculating with absolutely no evidence or knowledge to back it up) that something intended to be optically clear in a lab environment is probably manufactured to significantly different standards. I'm really intrigued by this now!
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Apr 7, 2016 00:52
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I haven't gotten around to testing anything further yet, my ideas are to see about acrylic cement vs. polycarbonate (it should weld one but not the other), or just test cutting a small area in my laser cutter. They are very different physically it's true but like I said, this is all like 1/4" and 1/2" stuff. I'm only used to how 1/8 and 1/16 stuff "feels". Polycarb doesn't shatter but I don't have any bright ideas on testing that short of hitting a whole piece with a hammer, but I don't want to mar one unmarked piece just to be all ??? about the next one anyway 
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Apr 7, 2016 02:42
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I've definitely gotten fogging on acrylic pieces cleaned with alcohol. The last batch job I did of 50 or so I only used water to wipe clean and it worked out great.
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Apr 7, 2016 03:26
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Is there a trick to cutting plywood to make sure the laser goes all the way through little imperfections? I seem to have found a power setting that works, but sometimes it just... doesn't in small spots.
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Apr 7, 2016 05:46
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Okay gently caress full spectrum and their lovely software. Been fighting with one of their setups for 8 hours now and still no respectable results.
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Apr 13, 2016 02:40
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lol welp, who's unsurprised
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Apr 19, 2016 17:07
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sounds like the attempts at chinese assembly went really drat poorly
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Apr 19, 2016 21:20
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It's funny to see that profile picture & expression beside that message. It comes off as sort of insincere.
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Apr 19, 2016 22:12
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Didn't get a response in the CNC thread so I'll ask here too, has anyone tried the JTech Photonics laser kit? It looks interesting, much lower power than the Chinese IR cutters, but my main interests are burning photos into wood and possibly using it to make masks on PCBs with laser printer toner anyways. http://jtechphotonics.com/?product=new-2-8w-laser-and-2-5amp-safety-compliant-driver-kit-with-us-style-power-adapter
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Apr 19, 2016 22:50
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A Yolo Wizard posted:sounds like the attempts at chinese assembly went really drat poorly Apparently their attempt to engineer a new PSU was disastrous and only completed this week. Still kind of glad to see it made in the us because then I only need to pay tax and not duty. 
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Apr 19, 2016 23:31
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Parts Kit posted:Didn't get a response in the CNC thread so I'll ask here too, has anyone tried the JTech Photonics laser kit? It looks interesting, much lower power than the Chinese IR cutters, but my main interests are burning photos into wood and possibly using it to make masks on PCBs with laser printer toner anyways. I can't speak to this module, but there are a million on alibaba that even come with their own frame, ranging from .5 to 3W.
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Apr 19, 2016 23:32
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Do you have a link? I'm finding a bunch of CO2 lasers and other random stuff like hair removal lasers instead.
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Apr 20, 2016 00:48
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Parts Kit posted:Do you have a link? I'm finding a bunch of CO2 lasers and other random stuff like hair removal lasers instead. This is the sort of thing I was talking about (aliexpress is very slightly easier to search on than alibaba ): http://www.aliexpress.com/w/wholesale-laser-engraver-diy.html
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Apr 20, 2016 05:25
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I actually have one of those. The laser is a "burning" laser, it's not ionizing radiation like from an e.g. CO2 laser. In other words, the laser makes hot and melts/burns. That's fine for some kinds of etching and junk (I get pretty nice results on thermal paper for example at a really low duty cycle, and no ventilation needed because no smoke or fumes.) However it won't cut anything except by burning it. I've meant to see what it can do to chocolate (will it melt it a little, enough to write on the chocolate by basically annealing it?) and had some nutso idea to try carving into wax with it or something. But besides that and the probably malware-ridden driver program there's nothing much to say about it. This was some 500mW diode one.
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Apr 20, 2016 06:23
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Mister Sinewave posted:I actually have one of those. The laser is a "burning" laser, it's not ionizing radiation like from an e.g. CO2 laser. In other words, the laser makes hot and melts/burns. That's fine for some kinds of etching and junk (I get pretty nice results on thermal paper for example at a really low duty cycle, and no ventilation needed because no smoke or fumes.) However it won't cut anything except by burning it. The difference in power level and air assist makes the engraver turn cutter. Ionizing radiation is a very different thing  And yeah, that kit looks like probably not as good a deal as the AliExpress kits because the machine parts (the expensive parts) aren't included.
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Apr 20, 2016 06:29
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Mister Sinewave posted:I actually have one of those. The laser is a "burning" laser, it's not ionizing radiation like from an e.g. CO2 laser. In other words, the laser makes hot and melts/burns. That's fine for some kinds of etching and junk (I get pretty nice results on thermal paper for example at a really low duty cycle, and no ventilation needed because no smoke or fumes.) However it won't cut anything except by burning it. As mentioned, you've definitely got some things mixed up; CO2 lasers don't have ionizing radiation at all. For what it's worth, diode lasers can still cut things, usually at much lower wattage than a CO2 laser. That said, the 500mW is what hampered you, not the fact that it's diode-based.
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Apr 20, 2016 07:07
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Does anyone here have experience with these "10W" diode lasers from Aliexpress? Its supposedly capable of marking metal. I would imagine its capable of cutting wood. http://www.aliexpress.com/item/10W-...22-1fcad76566a4
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Apr 20, 2016 17:42
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I didn't know co2 lasers couldn't ionize, shows what I know! What I was trying to say is that the ones like in that link don't in a practical sense act the same as a big cutter just scaled down. Sure all that's really different is size, power, air assist, etc but in a practical sense they're very different and can't do the same jobs. Maybe some of the really higher power ones would - never seen or used any - but not the little guys like in that link.
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Apr 20, 2016 22:54
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Mister Sinewave posted:I didn't know co2 lasers couldn't ionize, shows what I know! Any of those diode lasers that're 5W and higher can do some poo poo. That's what that Mr. Beam II uses, and it can do thin woods and acrylics and things.
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Apr 21, 2016 00:06
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That'd be cool to try. How thick of acrylic and wood are we talking?
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Apr 21, 2016 00:44
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Mister Sinewave posted:That'd be cool to try. How thick of acrylic and wood are we talking? The mr beam ii can do 5mm ply or 2mm acrylic at five watts. Dunno about the alibaba ones but i suspect they're similar.
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Apr 21, 2016 02:15
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I'm okay with it not cutting since etching/burning is my focus, but poo poo it'd be nice if it did both.
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Apr 21, 2016 02:27
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LurkingAsian posted:Its supposedly capable of marking metal. Hahaha no, absolutely not. It'll activate Thermark, though, which is rad and can provide centre marks and outlines such for finishing with hand tools.
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Apr 21, 2016 03:53
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Our makerspace group have been designing and gathering materials for a DIY cutter using a 5W laser like the ones above. Apparently they'll do useable amounts of plywood. Going the standard shop-bot style gantry design with scavenged smooth rod and stuff, using the most common (and therefore cheap) stock clamps and bearings we can find. Not sure if we're going belt or screw for the linear drive. Probably screw for the torque.
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Apr 21, 2016 15:06
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