Really liking the Microcenter (AKA Esun) ePA-CF (20% Carbon Fiber Reinforced Nylon). I have printed plenty of CF reinforced filament (PLA, ABS, PETG). They all look nice, but the CF leads to weaker interlayer bonding and brittle parts. But with the nylon the bonding is still great, and the CF helps the nylon not warp. Its like the best of both worlds.
Printing it from a cheap Rubbermaid cupboard storage container with desiccant inside, a printed spool roller base, and 4mm pushlock fitting with some tube.
Really nice considering the Microcenter CF-Nylon is $25.99. Just remember to keep it dry, and buy a hardened nozzle before you quickly wear out your brass one. I am doing 50mm/s, 0.15mm layers, 260C on the hotend, 70C on the bed with plain old gluestick.
Nice to know. What nozzle diameter do you use? My best overall filament ever so far is CFPLA from protopasta (wonderfully easy to print, super rigid, but PLA does not stand high temps enough and bridges are so-so admittedly). I was disappointed by Formfutura CF-PET (brittle imho, may be uselessly too much CF in it). I must try this one, I guess bridges are quite easy also because of the nylon binder.
@Jeremie_Francois right now using a E3D v6 with a 0.4mm. I just bought a 0.6mm nozzle as well that should be here soon. Looking forward to wider perimeters to see how strength is affected.
PLA-CF was always a bad idea. Why combine brittle with brittle? Nylon CF is the way to go. Lots of other good conbos out there though… I saw somebody post GFR-PP once, which would be pretty marvelous.
It’s not actually all that common that you need something strong/rigid and water/chemical resistant, but GFR-PP is what I’d do in that case. But ~$50/kg for CFR-PA is very attractive for regular mechanical stuff.
@Ryan_Carlyle I would say that it depends on what you are looking for. For me, CF-PLA is probably the easiest material I ever printed with such outstanding matte surface finish (no layers visible even with thick ones). Mechanically wise it still think it is stiffer (imo) than anything else, with a stiffness/weight ratio that excels in RC modelling for example (where/when heat is no issue, sure). I hardly see how it could be stiffer given that PLA adds to CF stiffness, contrary to softer PETG or Nylon, e.g. Now don’t read me wrong I do suspect that CF-Nylon is a must have in any decent stock for making better, durable mechanical parts. CFPLA does break easily and without notice when hit sharply.
@Eclsnowman what max thickness did you achieve with a 0.4mm nozzle? I was surprised with CF-PETG and a 0.6mm nozzle, I had to print thinner layers than I usually do to get a good bond and filling, which slowed down the prints a lot.
@Jeremie_Francois if you want stiff or stiffness/weight over all other mechanical properties, then yes, CF-PLA is a good option. It’s not a good option though for anything seeing impact loads, like drone parts or RC cars or many other applications people seem to think it’s a premium option for. It’s weaker on most metrics compared to virgin PLA. (PLA is also a very heavy plastic, comparatively speaking.)
It’s easy to print fiber-filled PLA because all fiber-filled filaments are lower-warp than their unfilled version. That’s why, in my opinion, it makes more sense to add glass or carbon fiber to warpy high-performance materials (nylon, polypropylene, Delrin, etc) and make them into well-behaved materials.
@Jeremie_Francois those prints are 0.15 and 0.2mm layer heights. 0.5mm extrusion width. I only just started testing it. I will know more as I do additional testing.
@Ryan_Carlyle yes I fully agree with the idea to add fibers to materials like nylon and I was an early advocate of this. Super light HIPS was also interesting (for the top hull) but I found it harder to print reliably and very fragile. The guys I worked for with drones were never ever crashing theirs, and they knew the issues well (they really were chasing grams to stay below 2kg overall). I “obviously” printed the motor supports in (significantly thicker) PETG… without fibers only b/c it did not exist at the time.
@Brad_Hill thanks, i like to think I have my printers pretty dialed in. But even if I didn’t… It’s amazing how well layer lines disappear into matte black surfaces. This filament is good at hiding your sins
@Greg_Dimas nylon does anneal, but it’s arguably better to leave it unannealed. Annealed nylon is a bit rubbery, but if you print fast, thin strands to get the polymer chains drawn out and strain-crystallized, it gets stronger and stiffer along the direction of the molecular orientation (ie along the strands). That reduces warping, oddly enough.
Not sure how the carbon fiber changes that though.
@Eclsnowman — where did you find those tubing bulkheads for your dry box ? I’ve been using standard bowden tube ones and the M5 thread on them is quite shallow so the flanged nut I use on the other side only catches just about a single thread, and no room for a washer so tends to crack my box.
