For the last four years, I've tested 3D printers in several key ways. Hardware tests, like how fast it is or how well the print bed heats up, are important, but so is measuring print quality evenly across machines.
To ensure every printer gets the same test, I worked with a talented 3D artist to design a custom print that quickly shows quality issues from the most challenging tasks for any given printer.
Originally created by 3D artist Fixumdude, the CNET test print is designed as a benchmark for 3D printing, testing multiple aspects in a single handy print. We designed it to look like the prior CNET logo, but added a lot of technical hurdles to make it hard to print, while still looking cool. We also love a good branding opportunity around here.
Today, that test has met its match. I've finally come across a printer that passes with a perfect score. While others have come close, the Bambu Lab H2C is the first machine to achieve top marks across all the model's metrics.
Those beautiful layer lines are perfect all the way up the spire.
- The model is exactly 30mm tall (Dimensional accuracy test)
- The base is exactly 5mm tall (Dimensional accuracy test)
- The slash between the "C" and "NET" is 7mm wide (Dimensional accuracy test)
- The slash has overhangs at 50, 60, and 70 degrees (Overhang/cooling test)
- The slash has bridging -- gaps where filament prints in midair -- from 8mm to 24mm in 4mm increments (Cooling/Bridging test)
- The edge of the C has a circle with a diameter of 15mm (Arch printing test)
- On the face of the T are two CNET logos, one embossed and one engraved (Ringing test)
- Two spires mark the tail and the cross of the T (Stringing/Small point test)
- Four pegs are inserted in the slash with gaps around them at 0.2, 0.3, 0.4 and 0.5mm increments (Bed adhesion/Tolerance test)
While I do a lot of other printing on each machine, these nine tests form the backbone of 3D printer testing here at CNET. So far, no other 3D printer has managed to pass all nine of these except the Bambu Lab H2C. The only other machine that came close was the Prusa Core One, but the overhangs and bridging were noticeably not as good as the H2C.
Bambu Lab H2C test print results
| Testing parameter | Target result to be considered perfect | H2C actual result |
|---|---|---|
| Dimensional accuracy (Z axis) | 30mm +/- 0.1mm | 30mm |
| Dimensional accuracy (base) | 5mm +/- 0.1mm | 5mm |
| Dimensional accuracy (Slash width) | 7mm +/- 0.1mm | 7.1mm |
| Overhang test | Smooth layer transitions on 50, 60 and 70 degree overhang | Passed |
| Bridging test | No visible drooping filament on any bridge | Passed |
| C circle diameter (vertical) | 15mm +/- 0.2mm | 14.8mm |
| C circle diameter (horizontal) | 15mm +/- 0.1mm | 15mm |
| CNET logo ringing test (emboss) | No visible ringing under macro zoom | Passed |
| CNET logo ringing test (engraved) | No visible ringing under macro zoom | Passed |
| Spire test (stringing) | No visible stringing | Passed |
| Spire test (point cooling) | Sharp edges on both spires and a fine point | Passed |
| Tolerance test | 0.2, 0.3, 0.4 and 0.5mm pegs are loose and removable | 0.2, 0.3, 0.4 and 0.5mm Passed |
The tests do allow for some variance. Nothing is truly perfect, and melted plastic will never be 100% accurate. When I run the tests, I see a variance that allows a printer to achieve a standard pass, which is about 0.1 to 0.2mm more than the "perfect score" results, and every printer on my best list has achieved that result. You can see that the H2C has done extremely well across the board.
Bambu Lab's latest flagship 3D printer features a dual extruder setup, with the right extruder capable of hot-swapping six nozzles on the fly. I'm still testing it fully, so I don't have a review yet, but I was blown away by how well it printed this model. It's not even doing anything incredibly complicated to achieve these results. Just hundreds of tiny tweaks that, when you put them together, produce fantastic, repeatable results.
The H2C is one of the first consumer-grade "Indx" 3D printers. Its Vortek nozzle-changing system lets you hot-swap six nozzles, reducing waste and speeding up complex prints. It's Bambu's flagship, and with that high honor comes a high price. It's not for everyone, but it is a glimpse at what the future holds.
3D printers have improved enormously. Even four years ago, this test would have stumped most models, but now we have a printer that can ace the test. It's also cool to know that the way I test them will have to change to keep up. Back to the drawing board for me.
