While we've printed quite a bit of filled nylon (CF, GF), and do have some other nylon on hand, printing unfilled PA6 proved much
easier than expected.
The results were also really excellent. But there are caveats to getting good results.
All testing was performed on a QIDI Max3 with V2.5 hot end, 0.4 PCD diamond nozzle, a generic black PEI build plate, and our own
low viscosity bed glue.
1. This filament needs to be thoroughly dried. The listing says 80C for 6 hrs before each time you pull it out to print. That is not
enough time at 80C.
* Not knowing whether the clear spool was PC or simply clear ABS, we adhered to the 80C limit, drying it in our lab oven. We weighed the spool on an analytical balance (good to 0.01gm) every 2 hrs to track the weight. When it stops losing weight from moisture, it's dry. After 2 hours it had lost just under 2 grams, but the weight kept dropping. It stabilized at 22 to 23 hrs with a total loss of 4.72 grams of water. That's quite bit, especially since the spool came packed in an aluminized vacuum sealed bag. The red PA6 is also a new launch at this time, so it's not been sitting for 6 or 12 months absorbing additional moisture. Plan on 24 hrs or more at 80C and likely 72 hours or more if your dryer can only hit 70C. PA6 is incredibly hygroscopic.
2. You need to be comfortable building a filament profile by doing calibration testing such as using Orca Slicer's tools. This PA6 can
produce excellent parts, but do not expect that it will print perfectly without prior experience with engineering filaments.
Settings:
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The temperature recommendations of 220-260C are too low. If properly and fully dried, this PA6 can easily be printed at 285C, but great layer bonding was achieved at 270C without stringing.
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Cooling varies by printer, but on the Max3 cooling was set to 20%-40% min/max. The idea is very little cooling and printing
slowly.
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Enclosed chamber with active heating was set to 55C. Larger parts may require a heat soak and higher chamber temps to prevent warping.
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Extrusion Multiplier (Flow Ratio) was best at 1.04, which is the highest we've needed for any filament on a 0.4 nozzle. PA was also high at 0.076 in this setup.
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Max flow rate at 270C was 9.5mm3/sec using the Orca serpentine max flow rate test. There were no signs of skipped extrusions until > 15 mm3/sec, but the layer bonding dropped dramatically above 9.5. We conservatively set max flow rate to 6.0 for printing parts.
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Adhesion - PA has no molecular bond to PEI at elevated temperature. Unless you are running a Garolite plate or similar, glue is not recommended, it is REQUIRED. We ran 100C for bed temp (again, at the very top of the manufacturer's recommended range) but at this point, adhesion was good. It could stand to be 105 or 110C for larger parts.
Spool Info
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The seller quickly replied to a message asking about the spool and drying temp. They clarified that the spool is PC and weighs 167 gms empty, for those of us who track inventory. When fully dried, the spool weighed 1169.54gms so it's a full 1kg.
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Knowing that the spool is PC, in the future, we would dry it at 110C for 4-6 hrs while monitoring weight loss. There is no need to continue drying once the weight change levels off. In fact, over-drying can damage nylon filaments.
Observations
The spool was not evenly wound on the top layers, but there were no tangles or issues during printing.
Despite the aluminized well-sealed vacuum bag with a silica gel packet, the filament was clearly too wet to print.
Summary
All that aside, how did it print after a profile was dialed in? Awesome, to be honest. Much better than expected for an unfilled nylon. An excellent application for this red nylon was for the pictured hex bit holders for our Milwaukee tools. The dark red is not an exact match, but honestly better than some of the M18 accessories we've used! The PA6 has enough flex, and after some exposure to environmental moisture, will be incredibly tough when the tools get dropped. It also has enough give to allow the hex bits to fit
nice and tight without cracking. Another great application is for gears, as this is one area where nylon really excels.
If you expect to pull it out of the package, start printing with some standard profile, you will not be happy with your stringy and generally poor results.
Areas for improvement are for YXPolyer to update the drying procedure, temp ranges (220C is absurd as are the lower end of the bed temp range) and print the bare spool weight and spool material on right on the spool and in the Amazon listing.
HOWEVER, if you are well experienced with engineering filaments, have the right equipment to properly dry the filament, an enclosed printer with heated chamber, and are familiar with building a profile by doing calibration tests for flow ratio, PA, temp, cooling, etc, you will be rewarded with an excellent printing experience. We are honestly very impressed with this filament. The tree supports broke away more cleanly than expected for a nylon, but next time we'll still increase the interface distance a bit.
For advanced users this is a 5 star filament, based on printing results. The dark red looks amazing as well.
For those needing more guidance and who have never worked with severely hygroscopic materials before, this could be challenging
—— Project shared by Lee, Deep Forest Consulting, LLC