Guide · Mechanical upgrades
High-flow hotends: Volcano, CHT and Revo High Flow, with outside numbers
What limits flow, what E3D, Bondtech and BIQU state for their high-flow parts, and CNC Kitchen's measured numbers, each as one setup.
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Picks that fit
- Micro Swiss FlowTech hotend for Creality K1 / K1 Max / K1C / K1 SE (M3101)Check price on Amazon
Short answer
A high-flow hotend or nozzle lets plastic melt fast enough at higher speeds. Outside measurements show real gains, but each is one printer, one filament and one temperature. Read the maker's figure with its conditions, read the outside number as one setup, and derate any flow test result before you put it in your slicer.
Picks that fitAll picks and how to choose
- Micro Swiss FlowTech hotend for Creality K1 / K1 Max / K1C / K1 SE (M3101)Check price on Amazon
What limits flow
At high speed the limit is usually melting, not motion. The hotend has to heat the filament through before it leaves the nozzle. A longer melt zone or a nozzle that splits the strand gives the heat more time or more surface to work with. The result is measured as volumetric flow in mm³/s.
The three designs, as the makers describe them
Volcano. E3D's Volcano support page gives a maximum rated temperature of 300 °C, upgradable to 500 °C, and says the hotend uses the E3D Volcano nozzle. It lists a 30 W nominal heater at 12 or 24 V and 1.75 or 2.85 mm filament.[1]
CHT. Bondtech says its CHT nozzles split the filament into three thinner strands, and that meaningful flow gains need a nozzle of at least 0.6 mm.[2] It sells CHT nozzles to the RepRap, MK8 and Volcano standards, all with M6x1 threads.[2] We could not read Bondtech's CHT Volcano data sheet, and the product page gives no maximum temperature, so we cannot state the CHT Volcano's limits.
Revo High Flow. E3D lists Revo High Flow nozzles at a 300 °C maximum for 1.75 mm filament, in sizes from 0.4 to 1.4 mm.[3] E3D says the standard 40 W HeaterCore suffices for most uses and recommends the 60 W core for high-temperature materials such as polycarbonate.[3]
A maker's flow claim, with its conditions
BIQU states a maximum flow of 40 mm³/s for its Panda Revo, measured with HS PLA at 260 °C using a 0.4 mm High Flow nozzle.[4] That is the maker's own figure under its own conditions. Its spec table lists a 300 °C maximum temperature.[4] The Bambu P1 and X1 hotend guide covers which printers BIQU lists.
Picks that fit3 products
Volcano-type block: Bondtech's 0.8 mm CHT Volcano nozzle (600-C-CHT-VOL-175); Bondtech says CHT gains need 0.6 mm or more.
More on choosing
Bambu Lab P1P or P1S: the Panda Revo for P1P/P1S (1060000654); the X1C version is a separate listing. Creality K1, K1 Max or K1C: the Micro Swiss FlowTech M3101, a whole hotend whose hardware differs for older and newer K1 printers. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or the brand.
Bondtech CHT coated brass nozzle for Volcano, 0.8 mm (600‑C‑CHT‑VOL‑175)
BIQU Panda Revo hotend for Bambu Lab P1P / P1S / X1C
Micro Swiss FlowTech hotend for Creality K1 / K1 Max / K1C / K1 SE (M3101)
What CNC Kitchen measured
Each row is one published setup. None is a rated limit.
| Setup | Result | Source |
|---|---|---|
| E3D Hemera, 0.6 mm nozzles, PLA (2021) | CHT about 40 mm³/s, Volcano about 30, standard V6 about 15, at roughly 5% under-extrusion | [5] |
| Bambu X1/P1P, Voxel PLA at 220 °C (2023) | Stock hotend about 23 mm³/s, third-party hardened steel 24, genuine CHT 32, short AliExpress CHT 34 | [6] |
| Near-stock Ender-3 Pro, PLA (2022) | About 6 mm³/s at 200 °C, 8 at 220 °C, 12 at 240 °C | [7] |
| 0.4 mm nozzles, PLA at 215 °C (2022) | AliExpress "high-flow" nozzle dropped off around 30 mm³/s, Bondtech CHT peaked at 27, V6 at 16 | [8] |
The Hemera test weighed extrusions and used 5% under-extrusion as the practical limit. The Bambu test judged the endpoint by eye on OrcaSlicer's flow test. The Ender-3 Pro numbers show temperature mattering on its own, and the author notes that hotter printing also brings more stringing, blobs and emissions.[7]
The cheap "high-flow" nozzle
CNC Kitchen took apart one low-cost AliExpress high-flow nozzle. It found a standard nozzle with an enlarged bore and a loose copper insert, yet in its test that nozzle out-flowed both a genuine CHT and an E3D V6.[8] The author also noted rough machining, a leftover chip, and an insert that can be installed backwards. It was a single unit, so it tells you nothing about consistency or durability across sellers.
Derate before you print
A flow test shows a best case. OrcaSlicer calls its max volumetric speed result exactly that, and suggests reducing it by 10-20% or more for print quality and strength.[9] It adds that brand and color can change max flow within one material. The flow calibration guide shows where this test sits in the calibration order.
Next
Questions
How much faster can I print with a CHT nozzle?
It depends on the setup. In CNC Kitchen's 2021 test with 0.6 mm nozzles on an E3D Hemera, the CHT reached about 40 mm³/s against about 15 mm³/s for a standard V6. On a Bambu X1/P1P in 2023 the genuine CHT reached about 32 mm³/s against about 23 for the stock nozzle.[5][6]
Does a CHT help with a 0.4 mm nozzle?
Bondtech itself says meaningful flow gains need a CHT nozzle of at least 0.6 mm.[2]
Are cheap high-flow nozzles fake?
CNC Kitchen took apart one low-cost AliExpress high-flow nozzle and found a standard nozzle with an enlarged bore and a loose copper insert. It still out-flowed a genuine CHT in that single test, but the author noted rough machining and an insert that can go in backwards. One unit says nothing about the next.[8]
Why does my max flow test overstate what I can print at?
OrcaSlicer calls its max volumetric speed result a best case and suggests reducing it by 10-20% or more for quality and strength.[9]
What are the CHT Volcano's temperature limits?
We could not confirm them. Bondtech's CHT Volcano data sheet could not be read, and the CHT product page gives no maximum temperature.[2]