3DXTech Obsidian Nylon 6+CF V2: Onyx Alternative for Markforged and Open-Frame Printers (750 g, 1.75 mm)
Obsidian CF V2 is the second generation of 3DXTech's carbon fiber PA6 filament. The original version underperformed on Markforged printers, so they rebuilt the formula from scratch — and now position it as a direct drop-in alternative to Onyx. The TDS includes independent lab data comparing it head-to-head against Onyx on the same machine with identical settings. Available here in black, 750 g, 1.75 mm. Also compatible with open-frame printers capable of running PA6+CF.
Key Specs at a Glance
- PA6 copolymer with high-modulus carbon fiber reinforcement.
- Independently tested against Onyx on a Markforged X7 — data included in the TDS.
- HDT of 147 °C at 0.45 MPa, versus 145 °C for Onyx under the same test conditions.
- Nozzle: 265–285 °C | Bed: 90–110 °C | Enclosed chamber recommended.
- Hardened steel nozzle required.
- Dry at 80 °C for 6 hours before printing.
Is My Printer Compatible?
On Markforged machines, this is right in its element. For open-frame printers, you'll need a hotend that reaches 285 °C, a heated bed at 90–110 °C, a hardened steel nozzle, and ideally an enclosed build chamber — 3DXTech specifically recommends a heated enclosure. If your printer has a brass nozzle and you're not planning to upgrade it, skip this filament: carbon fiber will destroy it.
Does It Actually Match Onyx?
Here are the numbers straight from the 3DXTech TDS, tested on a Markforged X7 at 275 °C. Z-axis tensile: 23.4 MPa vs. 20.1 MPa for Onyx. XY-plane tensile: 23.8 vs. 26.1. Edge-on tensile: 31.0 vs. 31.9. Modulus is higher across all three orientations, and edge-on flexural strength also edges ahead (33.9 vs. 30.8 MPa). Unnotched Izod impact comes in slightly lower: 854 vs. 940 J/m. Overall: very comparable performance, with a stiffness advantage. For more on this category of materials, check out our complete guide to carbon fiber filament.
Technical Specifications
| Property |
Value |
| Material |
PA6 copolymer + carbon fiber |
| Diameter |
1.75 mm |
| Net weight |
750 g |
| Color |
Black |
| Nozzle temperature |
265–285 °C |
| Bed temperature |
90–110 °C |
| Enclosure |
Recommended |
| Nozzle type |
Hardened steel |
| Layer height |
0.10 mm or greater |
| Drying |
80 °C, 6 hours |
| Density (ISO 1183) |
1.2 g/cm³ |
| Z-axis tensile (ASTM D638) |
23.4 MPa / modulus 1,351 MPa |
| XY-plane tensile |
23.8 MPa / modulus 731 MPa |
| Edge-on tensile |
31.0 MPa / modulus 1,510 MPa |
| Edge-on flexural (ASTM D790) |
33.9 MPa / modulus 1,048 MPa |
| Unnotched Izod impact (ASTM D256) |
854 J/m |
| HDT at 0.45 MPa (ISO 75) |
147 °C |
Printing Tips
- Hardened steel nozzle is mandatory — 3DXTech explicitly states this in their documentation.
- Dry for 6 hours at 80 °C before printing; moisture in PA6 shows up immediately in surface quality. Browse our filament dryers.
- TDS test conditions: 275 °C, 30 mm/s, 0.20 mm layer height, solid infill, Markforged X7.
- On open-frame printers, enclose the build chamber and use a nylon-compatible bed adhesive.
- The 750 g spool fits the Bambu Lab AMS according to 3DXTech — but watch for moisture absorption if you leave it loaded for extended periods.
FAQ
What format is this?
1.75 mm diameter, 750 g spool, black. SKU 024BK00A-750G, verified on 3dxtech.com.
Is it compatible with Markforged printers?
Yes, 3DXTech positions it as a direct drop-in alternative to Onyx and has validated it on Markforged printers.
What about Bambu Lab or Prusa?
Yes, as long as they have a hardened nozzle and can reach 285 °C. 3DXTech lists it as compatible with any printer that supports PA6+CF.
Does it require a heated chamber?
3DXTech recommends one.
What is the heat resistance?
HDT of 147 °C at 0.45 MPa, per the TDS.
Why is there a V2?
3DXTech reformulated the material because the original version did not perform as expected on Markforged printers.
How long does it need to be dried?
80 °C for 6 hours, according to the 3DXTech datasheet.
Who conducted the testing?
According to the TDS, an independent laboratory — comparing each specimen against Onyx using the same printer, settings, and orientation.
