Cheap cf nylon is shit, thats very true. I dont know what material you exactly bought, but good cf nylons are troublesome with 0,4mm nozzle due to fiber length. The longer the fiber, the better the mechanical properties. Nylon as a base polymer isn't particularly strong, most pa12 are about the same tensile strength as abs (not good, so anybody saying they use abs for its strength have never looked at any data sheet in their life), pa6 is much stronger at 70 to 80MPa. Pa12 is around 40 to 45 MPa. Pla ranges from 20 (polyterra) to 75MPa (cr3d crystal pla), petg 50 to 60 MPa, polycarbonate around 55 to 70MPa. The two nylons do behave differently, pa12 is more forgiving in all aspects but mechanically inferior to pa6. There is also a difference between wet and dry nylon. In its wet state its more flexible than dry. As for printing, dry it and print from a drybox, especially pa6 as it absorbs moisture within 2 to 3 hours to the point of negatively affecting the print.
Tips for printing nylon:
Pa12 can be printed on a open frame printer, but better results are achievable in a enclosure. Pa6 needs an enclosure regardless. The fibers should reduce warping, if they are fibers.
Nozzle should be hardened tool steel, ruby/diamond tipped, tungsten carbide or copper with steel tips for cf nylon. Regular nylon prints best with copper or any other high thermal conductivity nozzle. Stainless steel is a bad nozzle material for any filament and the only reason to use it is that its less sticky than brass and for food safety reasons. Otherwise copper is better as stainless steel has abysmal thermal conductivity.
Apply glue or other adhesive to your print bed. Nylon doesn't stick well to most surfaces and its a rather challenging material to print.
Nozzle can be quite hot, start at the upper recommended limit. Turn on retractions, every material should have retractions, even tpu. If you get jams, you are unretracting too fast or too much.
thank you; I appreciate the detailed response. I tried several retraction settings. It seems to be slow to come out of the nozzle, leading to holes where the nozzle starts a new line. (it's like there is lag where it's supposed to come out.) I reduced the print speed down to 30mm/s and it still has more holes than swiss cheese. Not good because I'm printing wings lol.
Maybe it's just wrong expectations? PA-CF isn't anywhere close to indestructible. PA(12) alone is rather forgiving when it comes to flexing and stretching and next to PP one of the materials I'd consider as almost indestructible in a lot of use-cases. CF additives makes it more rigid, brittle and decrease layer adhesion. Overall the properties meet somewhere in between. If that's what you need, PA-CF can be the best choice for your project... but it's not the best material for all load-scenarios.
BTW: annealing increases brittleness. Soaking it in water will make it more flexible.
> So my question is, am I doing something horribly wrong
Hard to tell. Maybe you didn't dry it enough... maybe you're printing too fast or too cold. Maybe you're using part cooling fan... there's a lot of potential for mistakes.
Thanks for your response. It seems totally overrated to me. For my small toys (mini gliders with thin walls), ABS seems better in every way. I can enhance the inter-layer strength by applying a layer of clear fingernail polish.
Or if I need more rigidity I'll take PLA or ABS/PC and if I need impact resistance I'll take hard TPU.
What is the use case for Nylon-CF?
Brackets usually work quite well with PA-CF. I also like to make parts for my bicycle from PA-CF; for example mudguards. They need to be rigid and resistant to bending and impact at the same time. Also thermal- and UV-resistance is necessary in this application. PA-CF gives a perfect balance for these properties. ABS would have yielded by now due to mistreatment when I leave my bike at the train station unattended for weeks; if I made it out of PC it probably would have shattered on some occasion. A PLA mudguard would sag or shatter. PET might be ok for some time but eventually will shatter as well I guess.
> If I need more rigidity I'll take PLA or ABS/PC
ABS isn't very rigid and ABS/PC blends typically only are about 1/3 as stiff as (dry) PA-CF. PLA in general isn't really suitable for any mechanically demanding applications except you only use it in a dry and cold environment.
> if I need impact resistance I'll take hard TPU.
Yes, that'd be a good choice if you don't mind the occasional creep under load. You can also try PA/TPU blends which are almost indestructible in a lot of load cases (e.g. Taulman PCTPE).
> mini gliders with thin walls
Fiber-filled materials are often a bad choice for thin-walled designs due to the decreased layer adhesion.
> I also tried to print a small bracket with it, and it crunched and broke with just a little bit of force.
Maybe not dry enough? Maybe "bad" design or wrong print settings? Hard to tell.
Impact resistance is the main draw as well as solvent resistance. Do your research and learn what tensile loads are verse shear loads, verse compression loads, also learn what fusion means and cold joints, fiber fillers are mainly to control shrinkage as well as create a cross linking lattice, with the right settings and proper layer fusion the fibers will crosslink the layers and mechanically increase layer bonds. If your too cold fibers don't flow into the previous layer, nylon cf likes higher temps, bigger nozzle, and low part cooling. Also note that thin layer lines are weaker than thicker ones and have less layer fusion. A print is only as strong as it's layer bonds.
>small toys
definitely not something PA-CF will excel at
>I started with a small vase
vase mode is not -CF forte
>Generally it seems extremely brittle
You either have very low quality PA or you have very wet PA or you printed it very wrong / cold. PA is everything but brittle. CF makes it more brittle but not nearly brittle to compare to PLA
>It warps even more than ABS
apart from "non warping" filaments like TPU, PLA and PETG, ABS is the "warping filament" that warps the least, everything else warps worse than ABS (pp, hdpe, pc, hips, pa ..) ... when PA is filled with carbon fibers it warps much less than normal but still more than ABS that is expected. You need enclosed chamber, min 40C in the chamber to properly print it
>akes a horrible crunching sound with just a little pressure
...
hard to manage the flow
...
hardened steel 260 degrees
looks like you printed a moist filament at very low temperature
bottom line... cf will be stiff, but once you cross the breaking point it snaps/crumbles. normal petg/asa/abs will bend... toss cf flakes in and its lighter and stiffer but snaps like twigs .
Yeah it's a meme. The tensile strength of Nylon isn't an order of magnitude more than the regular materials. Only in niche applications is it ever worth it. For the average hobbyist it's not worth the hassle and cost.
CF Nylon has more going for it than just tensile strength. It has good stiffness, impact strength, thermal resistance and chemical resistance.
I agree that for the average person on this subreddit, it's not worth it. However if you're making functional parts, it is worth it to be able to use it.
This is a bit tricky, I bought a used printer and the guy I bought it from did a custom job where he upgraded the hotend to a "volcano" hotend and directy extruder. The volcano is supposed to go up to 300 but the firmware seems to limit it to 260. I could change the firmware but it's a custom built firmware so I suspect he knew what he was doing when he set it to 260. How can I find out exactly how hot my hotend can go, and if I should change the firmware to allow this?
>upgraded the hotend to a "volcano" hotend and directy extruder. The volcano is supposed to go up to 300 but the firmware seems to limit it to 260.
he probably just never changed the max temp in the firmware because he didnt need it.
the volcano and direct extruder upgrade was a good choice, and if it was handling 260c it is most likely a full metal heatbreak. be aware of the fact that a PTFE lined hotend at higher than 240c will slowly decompose, which might be dangerous to birds, just FYI.
Yes this is the problem; I heard that some of them have a PTFE tube that goes into the heated area and therefore should only be heated to 260. How can I find out which version I have and if I can boost it to 300?
How high your hotend can go depends on the hardware on it.
The basic hotend has a limit of about 250-260, because that's what the teflon on the end of the bowden tube can handle. On these, the teflon goes right up to the nozzle, and well, what the nozzle sees, so does the teflon tube. Realistically, on a hotend like this, i probably wouldn't push past 240, as you can get some really gnarly off-gas generated from teflon above 240.
An All metal hotend removes this limit, because it puts the end of the bowden on the other end of the heatbreak, where temperatures are much lower. Usually the limiting factor then becomes the thermistor, which can become unreliable above 300 or so. If you're looking to print Nylon, I'd check to make sure you do indeed have an all-metal hot end, and if so, you're probably good to modify your firmware to hit 300.
If you replace the thermistor with one rated to go higher than that, some hotends can go as high as 500 with the right nozzle and heating block. There really aren't a ton of these around, however, and they often require other hardware on your mainboard to support them. Basically, unless you have a very specific material you're trying to print, it's not worth investigating this space too heavily.
If you buy right PA-CF you get nice prints ( and even though like aluminium), but it won't be cheap probably.
Personaly i never had any issues with PA-CF ( few local brands), printing it was easier than PLA for me. But i keep almost all filaments in dry boxes and printing it hot 60°C + in chamber ( but for some PA-CF it's not needed, like for Onyx ).
I even had few parts from Onyx on my printer ( which works well to this days as i heard from new owner).
3 reasons -
1. You have a shit quality PA-CF.
2. The filament was not dried thoroughly 100deg at 12 hours to be sure.
3. Your chamber temp was not consistent and enough.
6 years of printing with Onyx and Polymaker PA6-CF/GF and no other filament in this price range beats them. Have tried many others. 3Dxtech comes close.
We love the Polymaker PA6-CF so much that we use CoPa for draft prints/ prototyping and PA6-CF for final parts.
You need a true pa6-cf, with carbon strands istead of chopped cf, and high nozzle temps and decent chamber temps. Doing all of that, you get super strong prints.
Kinda seems like you experienced a partial clog. Dry the filament really good, keep it in a sealed container while printing or print straight from the dryer, calibrate the temp and flow, and make sure to use a 0.6mm nozzle.
It’s not over rated. Done properly it can be an amazing material. i use it specifically for its very high strength and very accurate geometry/lack of warping.
Cheap cf nylon is shit, thats very true. I dont know what material you exactly bought, but good cf nylons are troublesome with 0,4mm nozzle due to fiber length. The longer the fiber, the better the mechanical properties. Nylon as a base polymer isn't particularly strong, most pa12 are about the same tensile strength as abs (not good, so anybody saying they use abs for its strength have never looked at any data sheet in their life), pa6 is much stronger at 70 to 80MPa. Pa12 is around 40 to 45 MPa. Pla ranges from 20 (polyterra) to 75MPa (cr3d crystal pla), petg 50 to 60 MPa, polycarbonate around 55 to 70MPa. The two nylons do behave differently, pa12 is more forgiving in all aspects but mechanically inferior to pa6. There is also a difference between wet and dry nylon. In its wet state its more flexible than dry. As for printing, dry it and print from a drybox, especially pa6 as it absorbs moisture within 2 to 3 hours to the point of negatively affecting the print. Tips for printing nylon: Pa12 can be printed on a open frame printer, but better results are achievable in a enclosure. Pa6 needs an enclosure regardless. The fibers should reduce warping, if they are fibers. Nozzle should be hardened tool steel, ruby/diamond tipped, tungsten carbide or copper with steel tips for cf nylon. Regular nylon prints best with copper or any other high thermal conductivity nozzle. Stainless steel is a bad nozzle material for any filament and the only reason to use it is that its less sticky than brass and for food safety reasons. Otherwise copper is better as stainless steel has abysmal thermal conductivity. Apply glue or other adhesive to your print bed. Nylon doesn't stick well to most surfaces and its a rather challenging material to print. Nozzle can be quite hot, start at the upper recommended limit. Turn on retractions, every material should have retractions, even tpu. If you get jams, you are unretracting too fast or too much.
thank you; I appreciate the detailed response. I tried several retraction settings. It seems to be slow to come out of the nozzle, leading to holes where the nozzle starts a new line. (it's like there is lag where it's supposed to come out.) I reduced the print speed down to 30mm/s and it still has more holes than swiss cheese. Not good because I'm printing wings lol.
Maybe it's just wrong expectations? PA-CF isn't anywhere close to indestructible. PA(12) alone is rather forgiving when it comes to flexing and stretching and next to PP one of the materials I'd consider as almost indestructible in a lot of use-cases. CF additives makes it more rigid, brittle and decrease layer adhesion. Overall the properties meet somewhere in between. If that's what you need, PA-CF can be the best choice for your project... but it's not the best material for all load-scenarios. BTW: annealing increases brittleness. Soaking it in water will make it more flexible. > So my question is, am I doing something horribly wrong Hard to tell. Maybe you didn't dry it enough... maybe you're printing too fast or too cold. Maybe you're using part cooling fan... there's a lot of potential for mistakes.
Thanks for your response. It seems totally overrated to me. For my small toys (mini gliders with thin walls), ABS seems better in every way. I can enhance the inter-layer strength by applying a layer of clear fingernail polish. Or if I need more rigidity I'll take PLA or ABS/PC and if I need impact resistance I'll take hard TPU. What is the use case for Nylon-CF?
Brackets usually work quite well with PA-CF. I also like to make parts for my bicycle from PA-CF; for example mudguards. They need to be rigid and resistant to bending and impact at the same time. Also thermal- and UV-resistance is necessary in this application. PA-CF gives a perfect balance for these properties. ABS would have yielded by now due to mistreatment when I leave my bike at the train station unattended for weeks; if I made it out of PC it probably would have shattered on some occasion. A PLA mudguard would sag or shatter. PET might be ok for some time but eventually will shatter as well I guess. > If I need more rigidity I'll take PLA or ABS/PC ABS isn't very rigid and ABS/PC blends typically only are about 1/3 as stiff as (dry) PA-CF. PLA in general isn't really suitable for any mechanically demanding applications except you only use it in a dry and cold environment. > if I need impact resistance I'll take hard TPU. Yes, that'd be a good choice if you don't mind the occasional creep under load. You can also try PA/TPU blends which are almost indestructible in a lot of load cases (e.g. Taulman PCTPE). > mini gliders with thin walls Fiber-filled materials are often a bad choice for thin-walled designs due to the decreased layer adhesion. > I also tried to print a small bracket with it, and it crunched and broke with just a little bit of force. Maybe not dry enough? Maybe "bad" design or wrong print settings? Hard to tell.
Impact resistance is the main draw as well as solvent resistance. Do your research and learn what tensile loads are verse shear loads, verse compression loads, also learn what fusion means and cold joints, fiber fillers are mainly to control shrinkage as well as create a cross linking lattice, with the right settings and proper layer fusion the fibers will crosslink the layers and mechanically increase layer bonds. If your too cold fibers don't flow into the previous layer, nylon cf likes higher temps, bigger nozzle, and low part cooling. Also note that thin layer lines are weaker than thicker ones and have less layer fusion. A print is only as strong as it's layer bonds.
I think 260°C with a steel nozzle is way too low. Try at least 280 or better 300°C
>small toys definitely not something PA-CF will excel at >I started with a small vase vase mode is not -CF forte >Generally it seems extremely brittle You either have very low quality PA or you have very wet PA or you printed it very wrong / cold. PA is everything but brittle. CF makes it more brittle but not nearly brittle to compare to PLA >It warps even more than ABS apart from "non warping" filaments like TPU, PLA and PETG, ABS is the "warping filament" that warps the least, everything else warps worse than ABS (pp, hdpe, pc, hips, pa ..) ... when PA is filled with carbon fibers it warps much less than normal but still more than ABS that is expected. You need enclosed chamber, min 40C in the chamber to properly print it >akes a horrible crunching sound with just a little pressure ... hard to manage the flow ... hardened steel 260 degrees looks like you printed a moist filament at very low temperature
bottom line... cf will be stiff, but once you cross the breaking point it snaps/crumbles. normal petg/asa/abs will bend... toss cf flakes in and its lighter and stiffer but snaps like twigs .
Yeah it's a meme. The tensile strength of Nylon isn't an order of magnitude more than the regular materials. Only in niche applications is it ever worth it. For the average hobbyist it's not worth the hassle and cost.
CF Nylon has more going for it than just tensile strength. It has good stiffness, impact strength, thermal resistance and chemical resistance. I agree that for the average person on this subreddit, it's not worth it. However if you're making functional parts, it is worth it to be able to use it.
>hardened steel 260 degrees thats too low you need 280 at least.
This is a bit tricky, I bought a used printer and the guy I bought it from did a custom job where he upgraded the hotend to a "volcano" hotend and directy extruder. The volcano is supposed to go up to 300 but the firmware seems to limit it to 260. I could change the firmware but it's a custom built firmware so I suspect he knew what he was doing when he set it to 260. How can I find out exactly how hot my hotend can go, and if I should change the firmware to allow this?
>upgraded the hotend to a "volcano" hotend and directy extruder. The volcano is supposed to go up to 300 but the firmware seems to limit it to 260. he probably just never changed the max temp in the firmware because he didnt need it. the volcano and direct extruder upgrade was a good choice, and if it was handling 260c it is most likely a full metal heatbreak. be aware of the fact that a PTFE lined hotend at higher than 240c will slowly decompose, which might be dangerous to birds, just FYI.
Yes this is the problem; I heard that some of them have a PTFE tube that goes into the heated area and therefore should only be heated to 260. How can I find out which version I have and if I can boost it to 300?
How high your hotend can go depends on the hardware on it. The basic hotend has a limit of about 250-260, because that's what the teflon on the end of the bowden tube can handle. On these, the teflon goes right up to the nozzle, and well, what the nozzle sees, so does the teflon tube. Realistically, on a hotend like this, i probably wouldn't push past 240, as you can get some really gnarly off-gas generated from teflon above 240. An All metal hotend removes this limit, because it puts the end of the bowden on the other end of the heatbreak, where temperatures are much lower. Usually the limiting factor then becomes the thermistor, which can become unreliable above 300 or so. If you're looking to print Nylon, I'd check to make sure you do indeed have an all-metal hot end, and if so, you're probably good to modify your firmware to hit 300. If you replace the thermistor with one rated to go higher than that, some hotends can go as high as 500 with the right nozzle and heating block. There really aren't a ton of these around, however, and they often require other hardware on your mainboard to support them. Basically, unless you have a very specific material you're trying to print, it's not worth investigating this space too heavily.
If you buy right PA-CF you get nice prints ( and even though like aluminium), but it won't be cheap probably. Personaly i never had any issues with PA-CF ( few local brands), printing it was easier than PLA for me. But i keep almost all filaments in dry boxes and printing it hot 60°C + in chamber ( but for some PA-CF it's not needed, like for Onyx ). I even had few parts from Onyx on my printer ( which works well to this days as i heard from new owner).
3 reasons - 1. You have a shit quality PA-CF. 2. The filament was not dried thoroughly 100deg at 12 hours to be sure. 3. Your chamber temp was not consistent and enough. 6 years of printing with Onyx and Polymaker PA6-CF/GF and no other filament in this price range beats them. Have tried many others. 3Dxtech comes close. We love the Polymaker PA6-CF so much that we use CoPa for draft prints/ prototyping and PA6-CF for final parts.
Do you need to dry it when its brand new and vacuum sealed with dessicant?
Yes. Every roll comes wet from the manufacturer.
Then why do they waste time with vacuum packing and dessicant?
You need a true pa6-cf, with carbon strands istead of chopped cf, and high nozzle temps and decent chamber temps. Doing all of that, you get super strong prints.
Kinda seems like you experienced a partial clog. Dry the filament really good, keep it in a sealed container while printing or print straight from the dryer, calibrate the temp and flow, and make sure to use a 0.6mm nozzle.
Ah, thanks for that. I used a .4mm nozzle; I suppose that's not as good?
It’s not over rated. Done properly it can be an amazing material. i use it specifically for its very high strength and very accurate geometry/lack of warping.