i wanted to make something clear, but theproblem is that typical 3d prints, even if you use clear filament, just come out milkywhite tone instead of being properly clear. they diffract light too much, so while thelight still passes though, it gets bounced around inside the parts and scatters, whichcreates that translucent, but not quite transparent look.
durability of 3d printed objects, but colorfabb have had this article onlinefor a while where they are showing off incredibly, impressively clear prints. i’ve done a lot of printing and i thinki’m ready to show you how to reproduce these prints yourself.
okay, let’s see, colorfabb were using theirht filament for this, which is eastman’s tritan, so i believe it’s the same materialthat taulman used to make, just plainly called tritan, too. but the key here is that it’s a copolyester,so a material that is very closely related to the common pet and petg materials. in general, those are plastics that like tofuse together extremely well, so they turn into one solid piece of material instead ofkeeping those layer marks when you look through the print. i do have the colorfabb ht filament here,but i wanted to see how well just a standard
petg would do, so i did all my experimentswith the inexpensive das filament petg, but i’m sure any other clear polyester filamentis going to work basically the same for this. i had two different use cases here, the firstone being these solid parts like colorfabb showed that just look like they are one single,solid block of plastic with basically invisible layer lines on the inside and outside, atleast that was the goal, the other one being vase-like structures that have no infill,but only provide a shell, in my case, to scatter light. i was specifically looking into this for useas diffusers for lamps of various types. and i think i pretty much achieved that.
but let’s start with the solid parts. my test subject here is a spur gear from danielnoree’s openrc f1 design, it’s got some relatively complex surfaces on the side, largeflat areas on the top and bottom and this hub that is a bit of a smaller element whereyou’ll be able to see the light shine through from the top and the sides. i know, it’s not the most realistic designfor something that’s supposed to look good, but i think it’s a great object to tunein the process. plus, i’ve now clearly got plenty of sparesfor when i start building my first openrc models!
i’ll probably reprint these from abs ortaulman 910, though. so the first print was done with settingsthat i thought would make sense - i used 300 and 350ⵠlayers, 100% infill and regulartemperatures. but if you look at the part printed with thosesettings, it is translucent, but it is not transparent. yes, you can take a flashlight and shine itthrough and the part will glow, but it's not nearly as transparent as the samples colorfabbshowed. so the first idea was to increase flow, toclose what looked like tiny gaps between the extrusion lines, so i upped the extrusionrate to 105% first, and seeing that that improved
things a bit i tried again at 110%. and if you compare the original part at 100%flow and the new one at 110% it is already a lot more transparent, but we can also seethat it's starting to show over extrusion streaking on the top surface. so at this point, the amount of material seemslike its correctly filling every gap, but the rest of the print settings could probablystill use some work. so i tried the other extreme, going with 50âµlayers, and that immediately helped a lot. i think because the hotend now passes overthe same spots more often and sorta irons down the tracks more, we’re fusing the individualextrusion lines together more tightly to turn
them into an actual, single block of material. in fact, if you look at this hub part thati accidentally broke in half, you can see that both the surface where it broke and theinside of the part look like one single piece of petg, looking at just the crack, you’dbe hard-pressed to tell this thing was 3d printed at all. so next up, i tried increasing the materialflow on the 50âµ prints and increasing the layer height from 50âµ to 100âµ, and bothimproved transparency a bit. the 100âµ print was done with more perimeters,so you can see how those scatter light differently than solid criss-cross infill, but overallit didn’t look like that different from
the 50âµ prints other than the top surfacebeing a bit less smooth and now looking more like it was overextruded.. the 50âµ prints with more material i thinkwere the best ones of the entire series, where the one with a total of 15% extra materiallooks, i think, extremely good, while the one with 20% extra is a bit too much and startedto get quite messy on the top and side. it also has these fuzzies between the gearteeth where the nozzle was scraping off the extra material on each layer. for some reason, at the time i thought the100âµ prints were pretty much just as good as 50âµ ones, so i kept on printing partswith that setting.
looking back, i probably should have stuckwith 50âµ. anyways, these two benchies were printed with110% flowrate, but this one got a bit of a temperature boost, hoping that would helpwith everything fusing together. but instead, it turned out that the highertemperature actually decreased the clarity of the part and had a few other negative effectson quality. it’s a bit easier to see what exactly ishappening when you look at the gears that used different temperatures , and you cansee that, with a higher temperature, the petg actually sorta starts cooking and bubbling,and we’ll see that effect again in a second. in the main section of the gears, the highertemperature is fine and slightly improves
clarity, but up here at the hub, where theprinter slows down so that it doesn’t pump too much molten plastic onto one area in tooshort of a timeframe, up here you can see the plastic getting extremely cloudy. that’s because when the printer slows down,the filaments is sitting in the heated zone of the hotend longer and gets more time toheat up, cook and degrade. so to avoid that, either disable the coolingslowdown in the slicer or just print at a lower temperature overall. i think this benchy does look really goodand shows off the transparency or translucency really well, but it’s most visible whenyou look at the top and bottom of the parts,
since it’s almost like the low layer heightmakes the side surface somewhat milky. maybe i should try with an even lower layerheight at some point, 10âµ or something, but i’m pretty sure the prusa i3 mk2 is notup for that without dropping in a new extruder and some lower-pitch z-axis spindles. the stock setup has a physical resolutionof 20âµ, considering that the half-step position is the only microstepping angle you can reallytrust. but let’s get back to these parts. i also tried to improve the surface by eitherflame polishing it with a hot air gun set to 600â°c or sanding it beforehand, but withthe hot air gun, this unsanded spinner started
bubbling and softening up before it startedgetting more transparent, so that part’s gone, and when i tried to sand a part beforehand,yes, it did ultimately get a bit clearer, i think, after i heated the surface that wassanded to 1200 grit, but again, it’s really hard to find that optimum spot where the plasticneither bubbles nor softens up too much. but one nice thing you can do with heat, actuallyfor any filament, is to melt off the little hairs that petg in particular likes to pullwhen the hotend moves from one area to the next. high heat and a single pass are usually enoughto take care of them. and one last approach that didn’t reallywork with the benchy was the thicker layers
at 300âµ, even with the extrusion multipliercranked up, it did not turn out transparent at all. though print quality overall was a bit moreconsistent compared to the low-layer-height parts. so to recap for solid prints: with polyesterfilament, use a low layer height, 100% infill, obviously, and tune the extrusion multiplierso that you’re getting maybe a tiny bit of overextrusion. higher temperatures can help, but it’s reallyeasy to cook your filament that way. post-processing prints to improve the surfaceis hard to do right, at least with heat.
maybe those thick coatings can help here,i’ve played around with spray-on clearcoats before, but they didn’t improve things atall. awesome, let’s check out how these partswere printed. these are all single-wall parts, most of theseyou could print with vase mode, which is a print mode that turns the entire print intoone long extrusion line, instead of having discrete layers, it just continuously keepsmoving the hotend up as it lays down plastic, so it’s one long spiral. however, this shroud does have a ridge uphere, which usually can’t be printed cleanly with vase mode.
but that’s not the point here. let’s start out with what makes these partslook better or worse than others, and essentially it’s the same thing again. it’s refraction wherever light transitionsfrom one medium into another, and here, that’s from the air into the plastic and back out. the layers act as tiny lenses because theyhave that round section on their end. that’s why this part right here will blurthings in the vertical direction, but not as much horizontally. for example with this shroud, i tried to usethat effect and create tiny microlenses that
would also diffuse light horizontally becausethis is supposed to be a diffuser for a lamp. you know, you have these individual leds andjust seeing each one through a clear shroud doesn’t make for a very attractive lightingsetup, so i have all these parts that create different diffusion patterns. most of these were printed with 300âµ layers,because if you compare it to the the one printed at 100âµ, they are so much clearer and crisperand less hazy white. of course, using thick layers and only a thinshell like this means that these parts print incredibly quickly and use very little material. this one was printed with just 25g of petgin 45 minutes, that’s hard to beat.
this little one i printed with a thicker extrusionwidth. but i can tell you one thing that doesn’twork, and that is leaving the printer at over 600% speed for the wrong file, i mean, itdid get the print done super fast, but clearly, it’s not quite what i wanted. so typically, with a .4mm nozzle, you’regoing to set it up to lay down like 0.42mm wide tracks. here, i went with a full mm, so two and ahalf times as wide as the nozzle, and while it’s not the greatest thing to do if youwant overhangs and details to come out great, i mean, you should be using a thicker nozzle,this part still came out looking great.
it’s not quite as clear, instead it’svery glossy if that’s the right word, but that might be due to the structure, too. it’s definitely better than using two individualperimeters, which would introduce that second interface where you’d potentially end upwith more diffraction. also, it’s very strong and stiff, as expected,but i did crack the bottom when i tried to remove it from the pei bed, petg, as usual,likes to stick to pei a bit too much, so usually, i’d recommend using a liquid surface finishon top of the pei that doesn’t stick quite as much, so something like printafix, or magigoo,or maybe glue stick if you can apply it evenly. but this technique of just using a singlewall isn’t great for every model.
this adalinda frog does come out really nicelooking with those thick layers, but wherever there’s a slope on the surface, the extrusionlines just get super droopy, like on the back, near the tail or on the wings. i did configure this print with two solidlayers on top and bottom and turned off any features that backfill surfaces, which wouldavoid these exact issues, but would also create these structures on the inside that just don’tlook great if you see the way they diffract light shining through it. alternatively, you could print it with a solidinfill and thin layers, but that would use up a lot of material and take a long, longtime to print.
so that’s how i printed these transparent/ translucent parts. i think they turned out great, especiallythese single-wall prints, they are going to look awesome installed somewhere with somelight in them. if you learned something, click that thumbsup, get subscribed if you aren’t already and whether you’ve freshly subscribed orhave been for a year or two, check that you have that bell toggled so that youtube sendsyou notifications as soon as a new video gets uploaded. kickbacks from affiliate links help me runthis channel, so if you want to try printing some clear stuff, too, there are is a linkto colorfabb’s ht material that will take
you to the right shop for your region, also,to the das filament petg, that’s not an affiliate link, i just like the material,it’s cheap, it consistently prints well, what more could you want. if you’re going to be shopping on aliexpress,matterhackers, amazon, ebay or igo3d, check out the shop links to them from the videodescription.
or if you want to directly support what i’mdoing here, head over to patreon to chip in a dollar or two per month, or more, i’mnot going to judge you, that is always appreciated and you’ll be invited to join an exclusivelive q&a hangout as well. so thanks for watching, and i’ll see youin the next one.
