The Maker’s Toolbox: Bambu Lab H2C 3D Printer Review

What are the differences between the Bambu Lab H2C and H2D? And more importantly: which one should you buy? I’m going to help you answer those questions in this review of the Bambu Lab H2C 3D printer.

The basics

The H Series is Bambu Lab’s new flagship line of 3D printers. They’re the largest models that Bambu Lab currently offers and they have the most features. At the time of writing, there are four models in the line:

• H2S: Single extruder
• H2D: Dual extruder
• H2D Pro: H2D with some minor enterprise-friendly upgrades
• H2C: Dual extruder + Vortek

The H2S is pretty easy to understand, because it has a single extruder and single hot end, just like most 3D printers on the market. It can still print multiple materials if you use an AMS unit, but all of the filament goes through that one nozzle.

The H2D is a dual-extruder model, with both extruders riding on one carriage (unlike an IDEX printer). But the H2D can move those nozzles up and down, which is a big upgrade compared to traditional dual-extruder designs. That lifting action prevents dragging and other alignment issues. Importantly, the nozzles have separate inputs, so you need two AMS units if you want to print multiple materials from both nozzles.

The H2D Pro has improvements to networking and thermal stability. Details are limited, as the “Pro” in the name is literal and this model seems to be intended solely for enterprise customers. As far as I can tell, the upgrades aren’t anything the rest of us would care much about.

The H2C is a dual-extruder model like the H2D, but with a massive difference: the Vortek Hotend Changer System. That lets the printer switch between six hotends/nozzles on the right extruder, which has some interesting potential.

All of the H Series models are available in a Laser version.

I have already reviewed the Bambu Lab H2D here, so this review will focus on Vortek and the other differences between the H2D and H2C.

Vortek

Vortek is kind of like a toolchanger system, like on a Prusa XL or Snapmaker U1, except those swap out the entire toolhead (extruder, hot end, and nozzle) and Vortek only swaps the hot end/nozzle.

Bambu designed a special hot end/nozzle assembly specifically for Vortek, which heats very rapidly via induction. That inductive heating eliminates the need for hot end wires, which makes the swapping process practical.

The H2C has a rack of six of those nozzles on the right side, so the Vortek system can swap them in and out of the right extruder. The left extruder, its hot end, and its nozzle are the same as on the H2D. As with the H2D, you need separate AMS units to feed the right and left sides.

Vortek has been somewhat controversial in the 3D printing community, because filament swaps are slower than you’d get with a true toolchanger. The H2C still has to feed filament from the AMS unit, still has to heat the hot end during swaps, and still has to prime new filament in the hot end.

However, it does offer some serious benefits compared to the H2D. Those benefits include faster filament swaps, significantly less purge waste, and some practical bonuses that you may not have considered. I’ll dive deeper into those later in this review.

H2C vs. H2D differences

The Vortek system is, of course, the biggest difference between the H2C and the H2D. But it isn’t the only difference. There are a couple of others that you’ll want to be aware of.

The most obvious is the price, because the H2C is more expensive. The H2D AMS Combo is currently on sale for $1,999, with a normal price of $2,299. The H2C AMS Combo is $2,399.

Then there is the build volume. Both machines have the exact same overall size, but the H2D has a slightly larger build volume. That’s because the H2C’s Vortek nozzle rack takes up some space.

The maximum volume of the H2D when using both nozzles is 350×320×325mm. For the H2C, that is 330×320×325mm. For both the H2D and the H2C, there is an area of the bed only accessible by the right nozzle and an area only accessible by the left nozzle. The H2C loses some of the area accessible by the right nozzle, because of the Vortek rack.

That also affects the build plates you can use—they are not interchangeable, because they are slightly different in size. If you get the H2C, you will not be able to use build plates made for the H2D.

And finally, only the H2C’s left nozzle matches the H2D. The H2C’s right nozzles are completely different and made specifically for Vortek.

Printing and filament swapping

Now that you understand the physical differences between the Bambu Lab H2C and H2D, we can get to the real-world comparisons that you actually care about. Does the Vortek system matter? Does it speed things up?

The shorter answers are: yes and yes.

I wanted to know if the Vortek system provided a real, noticeable difference in filament swap speed, so I set up the most conservative test I could think of. My goal was to avoid giving the H2C a huge advantage, because I wanted to see if Vortek would still be beneficial in even a basic scenario.

The test was the same part (a Makita drill battery holder) printed on both the H2C and H2D, with the same filament materials and the same settings. Each printer had a single job to print three copies of the part, each in a different color. The left nozzle would get one color and the right nozzle would have to switch between two colors on every layer.

The H2D finished in 5 hours and 28 minutes, while the H2C finished in 4 hours and 5 minutes. So, the H2D took about 34% longer to finish the same job. And the H2D used 145g of filament compared to the H2C’s 111g, so the H2C saved quite a bit of filament on purging, too.

That is significant, in my opinion. And remember, that was a conservative test. Adding more filament swaps per layer would make the effect even more pronounced.

So while the Vortek system isn’t as “good” as a true toolchanger, it does make a pretty big difference. And buying a Vortek nozzle ($39.99 for a standard model) is a lot more affordable than a complete toolhead (~$355 for Prusa XL Nextruder).

Materials and nozzle sizes

Aside from the filament swap speed and reduced purge waste, the Vortek system provides a couple of other advantages that I think are worth talking about.

The first is that you can dedicate a nozzle to a filament, if you want. That doesn’t matter most of the time, but it can be helpful for certain materials.

I have dedicated a nozzle to TPU for AMS filament, for example, because TPU can be finicky, which can necessitate cold-pulls when swapping back and forth with rigid filament. By dedicating a nozzle to TPU, I never have to worry about that.

Even more exciting is the potential afforded by having many different nozzle sizes at your disposal. You can print with a 0.2mm nozzle for one part, then with a 0.8mm nozzle on the next—all without having to manually swap nozzles.

But that’s just the beginning, because you will also be able to swap between nozzle sizes during a print. Use that 0.8mm nozzle to quickly build up the bulk of the part, then use the 0.2mm nozzle to print the fine details.

That isn’t an option quite yet, but it is supposed to be added to Bambu Studio soon and I think that alone would make the H2C a compelling option.

Vision Encoder Plate

This is something I wanted to include in my H2D review, but I didn’t get the Vision Encoder Plate in time to do that. However, Bambu Lab sent me a Vision Encoder Plate for the H2C, so now I can talk about my experience with it.

The Vision Encoder Plate temporarily replaces the build plate and the printer uses it to provide feedback for positional calibration. 3D printer stepper motors are normally open-loop actuators, so the printer doesn’t know if they’ve moved exactly as expected (or if they did, but the belt slipped). The Vision Encoder Plate, in combination with the toolhead camera, lets the printer see how it truly moves in the real world.

You don’t need to use the Vision Encoder Plate before every print. You just put it on, run the calibration, and then take it back off. That calibration should be good for a while—though it isn’t clear exactly how long.

Does it actually help? Bambu Lab says it enables motion accuracy below 50μm (0.05mm), which is pretty incredible.

To test that, I printed the same part twice. The first print was immediately before using the Vision Encoder Plate and the second print was immediately after.

The part was just a large rectangle. I chose that because it would be easy to measure and motion inaccuracy effects would be more noticeable over longer distances. The nominal part size was 275.00×100.00×10.00mm and both tests were done in PLA Basic with a 0.4mm nozzle at 0.24mm layer height, using the standard settings.

The pre-calibration part came out to 274.44×99.71×10.14mm.

The post-calibration part came out to 274.56×99.68×10.17mm.

What does that tell us? In my case, I think it means that my motion accuracy was probably already good and the Vision Encoder Plate calibration didn’t really need to do anything.

Why are both so far off from nominal if Bambu Lab says this provides motion accuracy below 50μm?

Because motion accuracy is only one piece of the puzzle when it comes to the dimensions and tolerances of 3D-printed parts. Everything from tiny variations in filament diameter to thermal expansion to slicer settings can affect that.

I have not tuned anything, so this test was with the default standard settings. If I took the time to measure and average out the filament diameter, then really fine-tune the settings, I could probably get tolerances within +/- 0.1mm, which is great for 3D printing.

The Vision Encoder Plate is a good idea, in my opinion, but it will likely only be useful and worth purchasing if you suspect your printer’s actual motion accuracy is off. Otherwise, standard tuning procedures are enough.

The verdict

Now we can come back around and answer the important questions: is the Bambu Lab H2C good? Is the Vortek system good? Should you buy an H2D or an H2C?

I think the H2C is amazing. It is an incredible printer and very pleasant to use, just like the H2D. Yes, buying it requires a hefty investment. But that $2,399 includes a full set of hot ends for the Vortek system and an AMS 2 Pro unit, so the price is reasonable considering the capability and everything you’re getting.

I also think the Vortek system is pretty brilliant. It provides many of the benefits of a toolchanger, but at a much more accessible price. It isn’t quite as good as a toolchanger, but it isn’t far off.

To decide if you want an H2D or an H2C, I think you only need to answer one question: do you plan to print with multiple filament colors or materials?

If you only ever want to print with one filament at a time, then the H2S is enough. If you want to print with two, such as a primary material and support material, the H2D is enough. But if you want to print with more than that and time is a factor, you will definitely want to at least consider the H2C.

The H2D can do everything the H2C does, but it will take longer and produce more waste. If saving both time and material matters to you, then the higher price of the H2C is worth it.