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Has anyone printed with Polycarbonate here?

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  • Has anyone printed with Polycarbonate here?

    Some of the things I print are car parts and one upcoming project will be subjected to a decent amount of heat regularly. Up to this point I've really only dome some simple things like body panel clips, carpet retainers, and some dash badges and am now starting to worry that they're going to start failing as we move inti the summer temps.

    I've been using PETG because it looked like it would be able to handle the heat. However last night I finally got to test out a few pieces in the oven and even a modest 80c produced major issues.

    So this brings me to Polycarbonate. It looks like it has the highest glass transition and strength of all the filaments currently available but is also pretty difficult to print with.

    So my question remains... has anyone here printed with it and what has your e perience been? What do I need in the hotend dept to get up to 300c+?

  • #2
    I haven't personally printed with PETG, but we recently received a Dyze Design extruder/hot end assembly. Dyze Design is a company in Montreal Canada making some nice headway with extruders that are capable of 500 degrees C.

    -Tim@BRG

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    • #3
      I print polycarb on my Airwolf Axiom with great results. It's a very tough material, but can be very difficult to print without the proper setup. Airwolf actually has their "wolfbite mega" solution which helps the print stick to the glass bed. Smells funny but works well. I print at 270-290C with the bed at 145. So, very hot for everything. An enclosed print area is a must to keep everything warm.

      I don't have experience with polycarb on any other printers, but I do know the E3D hotends are meant for holding high temps for extended periods of time.

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      • #4
        Is the stuff as noxious and toxic as ABS?

        I do need to finish my cabinet and get the printer to it's final workspace before I can do it though (still in my livingroom right now lol) that much I know.

        I've seen a package deal online (can't remember where right now) that comes with build tack. Ever used that with it?

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        • #5
          Yes. It definitely has some nasty fumes. Can be worse than ABS in my opinion. Make sure your work space is well vented. Haven't tried it with BuildTak, but I love BuildTak with ABS and PLA.

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          • #6
            Originally posted by AndrewBougie View Post
            Yes. It definitely has some nasty fumes. Can be worse than ABS in my opinion. Make sure your work space is well vented. Haven't tried it with BuildTak, but I love BuildTak with ABS and PLA.
            Thanks Andrew. That's the one thing that for some reason I couldn't find mention of online but I presumed it would given how nasty it is when it burns.

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            • #7
              I have been playing with polycarbonate on my printer for about a week or so now and have learned a LOT. -- Here is what I have learned (considering I am still a complete n00b at). I have learned the following so far about it ...

              Here are my n00b tips,.. maybe I will look back at this in a year and laugh -- lol but this is what I have so far...


              *- YOU ABSOLUTELY want to keep the stuff 100% moisture free. What I did was use an old DE-hydrator (on 120C) and place it above my printer and feed the filament directly from inside it through the bottom via some tubing. I will turn on the DE-hydrator about an hour or 2 before starting my print if I want something of quality.

              *- At 260-270C, it does not flow out of the nozzle fast enough. I know people print it at those temps but it flows like peanut-butter, and is not all that good. It tends to want to bubble in the nozzle because of higher than normal compression in the tip. The resulting part contains lots of micro-bubbles and is brittle/breaks easily instead of being solid bending with the high resistance like it is supposed to. Pushing the filament down by hand reveals that it takes a tiny bit of force to get it moving. At 290-305C, the stuff flows like it really should, and will shoot out nice and fast when feeding it by hand. It prints very nice and clear and bonds very well.

              *- Because the temps are so high on the hot-end, you don't want it to sit in there not moving for for long periods of time. When the hot-end is up that high, and you are letting the printer sit idle,.. it will ooze a bit and air will get up into the tip. Every few minutes or so, you want to feed some by hand gently and push the air back out of the tip.

              *- If air does get into the tip at all, you will get micro-bubbles in your print, and it will start looking rough (it wall also make the resulting part very brittle). To prevent this,.. I always push through a good 4-5 inches of filament through the nozzle at full operating temp just before hitting start on the print. Pushing only a tiny bit, or only 1-2 inches through just won't cut it most of the time. If you do get bubbles/ etc. during the print after it has started,.. the best way to save it without touching the print head is to turn up the flow rate of the filament to 150% for a short period to flush it out and clear it up again. This is common to see if you have the layer height very small and it is on the first layers or 2 because the flow slows down as the tip gets really close to the part/bed and flow is restricted. If you don't stop it from doing this, the entire print may end up like that.

              *- The filament size should ALWAYS be measured with calipers to ensure its correct volume. Many times it is 1.68mm instead of 1.75mm due to shrinkage. This will throw off everything and make your part it stretch/shrink even more as it cools. As well, the hotter you have your nozzle set to, the more you have to compensate for shrinkage as the part cools. To reduce this, you want to put the filament feed to about 105% instead of 100% on the first layer or 2 for better bed adhesion with zero external fan cooling. It will have much less problems with shrinkage and coming loose. I see people complain that it has a lot of shrinkage, but I don't see them compensating for actual filament size form measuring its volume or compensating for it in the flow rate, then wondering why it snaps off the bed from shrinkage. After the first few layers, minimal external fan cooling is good if you are making small intricate work pieces.

              *- the entire area around your part as it prints needs to be at 50C+ to get good reliable printing. Printing without having a slightly hot environment is for poly, would be like sticking your printer in the deep-freezer and trying to print PLA. Poly is a much higher temp material, so the surrounding environment needs to be much higher for things to go well. Also,.. and a cooling fan can be your enemy sometimes. It can cause the print to be stringy and brittle if your cooling it too rapidly. You want the heat to bond the part well, and retain some of it so that it cools more slowly overall. I hardly ever use more than just a minimal fan breeze of air across the part just so that small detail work does not distort.

              *- 22-28mm/S feed-rate gives it time to bond without being stretched so much. I know that I see a lot of people running it faster than this when the temp is up at 300C, but if you watch it closely, it really does stretch at it as it is laying it down when your going fast. It also draws it from the tip more, and the tip can easily get air in it again, causing aeration like mentioned above. If your going too fast, or your flow rate is too small for that speed, you may still be getting fantastic looking results on the layer it is currently on,. but 1 or two layers later, as the lower layers cool, they can stretch and create imperfections (internal tearing and stretch-marks/streaking/etc. and make the part look bad again and weaken it.

              *- Make sure your filament feed system is VERY consistent and VERY loose going into the stepper feed to the hot-end. Inconsistent feed/tension, even slight, can cause noticeable distortion on the patterns, and/or can cause it to suddenly start getting bubbles in it again because it is letting air (cavitation) into the nozzle again. Sometimes even the slightest filament slippage or distortion at the feed-point can cause a translucent part to have streaks or visible imperfections in it that you don't want.


              *- CARDBOARD (in fact old cardboard that has been weathered and/or been wet and dried again in an oven) works VERY VERY WELL for holding larger parts to the bed if you don't want to use Kapton tape or something similar. I actually prefer cardboard over these other methods sometimes just because as it shrinks, it will have a bit of give to it just enough to allow for shrinkage and my parts always come out really nice and flat/straight instead of bowed like I see some people get. I suppose if my parts were very tall and slender,.. this give might be a problem,.. so it is all in the application I suppose. If your part is large and is going to want to bow upwards as it prints,.. Cardboard taped to the bed with painters tape usually already has has a slight bow the opposite direction and will usually compensate this already. Good to keep in mind as an alternative to Kapton on larger prints.

              *- PVC Electrical tape works well directly on the printer bed and poly sticks like mad to it for very small parts,.. but pvc tape is stretchy and can allow for the part to warp at its bottom. I use it sometimes when I want to make something really small, but it is not so good for thicker parts.

              *- Kapton tape and or an equivalent is typically the best choice, but you can't go cheap and use the really thin stuff. You need good quality tape. Forget about painters tape, cloth tape, etc. - It just won't stick well to it at all. Even with Kapton tape, sometimes to get it to stick well, pouring a bit of Dichloromethylene on the top of it, then smearing a bit if Polycarbonate (form an old part you made) smearing it around like a bit of butter then letting it dry for a minute or 2 is required if you are having problems with it staying in place.

              *- Keep some Dichloromethylene handy in a sealed syringe if your working with polycarbonate. It melts the stuff like water and can be used in tiny bits on the tip on an exacto knife, toothpick, etc. for cleaning up very fine details under a magnifying glass for a part you just made without having to scrape and scratch it up. It will leave a slight haze in the part if you use too much though. You can also boil the stuff and the fumes from it (caution very toxic- outdoors only) used to polish the outside of your part to a glass-like finish after you sand the part down with 320-grit then 1200 grit sand-paper.




              In a nut-shell,...

              *- Feed it from the inside of a de-hydator (120C for at least a couple hours before hand) if possible. don't leave it exposed to air that is not extremely dry without drying it out again before use.
              *- 290C - 305C, 105% flow rate on bottom layer.
              *- 22-28mm/S feed-rates. Yes, that slow even at those temps if you want good quality parts.
              *- Keep cooling to a minimum.
              *- 40-60% of measured filament thickness to layer height ratio (unless your printing something very very fine detailed). I.E. layer height of 0.15mm if your nozzle is 0.35mm
              *- cardboard is often your friend on large parts.

              That is just a bit of what I have learned so far,.. maybe it helps someone else out there, but like I said,.. I am a n00b at this but I do have some fantastic-looking parts I have made so far with polycarbonate. Maybe some folks that are more familiar with it can chime in and give their experiences as well. I am always up to learning new things and trying things out, and know well, what i have said here is likely not all that correct, but just what i have seen on my own.
              Last edited by Rawze; 12-26-2016, 11:55 AM.

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              • #8
                Here is something I am printing today with polycarbonate with a 0.3mm nozzle. this part is quite small, thin and precise, so I used kapton tape...

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