The three ceilings on every move
A printer’s top speed is the fastest the head can travel once it is up to speed. Three things stop it getting there. First, acceleration: every move speeds up, cruises and slows down, and Klipper’s documentation notes that a short move may have no cruising phase at all [8]. Second, vibration: faster acceleration shakes the frame and leaves ringing on walls, which input shaping counters [9]. Third, flow: the hotend can only melt so much plastic per second.
Whichever limit is lowest for a given move wins. On small parts acceleration usually wins. On large parts with long walls, flow usually wins.
Published speed, acceleration and flow figures
Only figures stated on the vendor pages we checked are listed. Most vendors publish top speed and acceleration but not hotend flow, which is the figure that matters most for long moves.
| Printer | Max speed | Max acceleration | Published hotend flow |
|---|---|---|---|
| Bambu Lab P1S | 500 mm/s [1] | 20 m/s² (20,000 mm/s²) [1] | 32 mm³/s with Bambu ABS at 280 °C [1] |
| Bambu Lab A1 | 500 mm/s [2] | 10,000 mm/s² [2] | Not stated on page checked |
| Bambu Lab A1 mini | 500 mm/s [3] | 10,000 mm/s² [3] | Not stated on page checked |
| Creality K1C | 600 mm/s [4] | ≤20,000 mm/s² [4] | Not stated on page checked |
| Creality K2 Plus | 600 mm/s [5] | ≤30,000 mm/s² [5] | Not listed [5] |
| Creality Hi | 500 mm/s [6] | ≤12,000 mm/s² [6] | Not listed [6] |
| Creality Ender-3 V3 SE | 250 mm/s [7] | ≤2,500 mm/s² [7] | Not stated on page checked |
Why acceleration matters more on small parts
A head starting from rest needs distance to reach speed. Using the standard formula, distance equals speed squared divided by twice the acceleration. Reaching 500 mm/s takes 12.5 mm at 10,000 mm/s², 6.25 mm at 20,000 mm/s² and about 4.2 mm at 30,000 mm/s². It needs the same distance again to stop.
Now picture a 20 mm wall on a small part. If the head accelerates for half the wall and brakes for the other half, its peak is the square root of acceleration times length: about 447 mm/s at 10,000 mm/s² and 632 mm/s at 20,000 mm/s². On a 5 mm detail the peaks drop to about 224 and 316 mm/s. The printer’s rated top speed never comes into play on most of the moves in a small, detailed part.
Worked example: turning flow into a real speed limit
Flow is volume per second. Each millimetre of a printed line has a cross-section of layer height times line width. With a 0.4 mm nozzle printing a 0.45 mm line at 0.2 mm layers, that is 0.2 × 0.45 = 0.09 mm² per millimetre of travel. Divide flow by 0.09 and you get the fastest speed the hotend can feed.
At the P1S’s published 32 mm³/s [1] that is about 356 mm/s. To print a 0.09 mm² line at 500 mm/s you would need 45 mm³/s, and 600 mm/s would need 54 mm³/s. The 32 mm³/s figure was measured with ABS at 280 °C on a single-wall test [1]; your filament may melt more slowly. OrcaSlicer’s calibration guide starts its flow test at 5 mm³/s and suggests reducing the result by 10 to 20 percent for quality and strength [10].
| Flow limit | Max speed at 0.2 mm × 0.45 mm | Max speed at 0.28 mm × 0.45 mm |
|---|---|---|
| 10 mm³/s | 111 mm/s | 79 mm/s |
| 15 mm³/s | 167 mm/s | 119 mm/s |
| 20 mm³/s | 222 mm/s | 159 mm/s |
| 32 mm³/s (P1S published) | 356 mm/s | 254 mm/s |
Input shaping: what it buys you
Input shaping does not make the printer faster by itself. Klipper’s documentation says the feature has pretty much no impact on print time by itself, while the maximum acceleration setting certainly does [9]. What input shaping does is let the printer use higher acceleration without ringing. Pushed too far, it causes smoothing and rounding of fine detail, so acceleration should be chosen to avoid that [9].
Vendors automate this. Bambu Lab says the A1 calibrates vibration resonance automatically for every print [2].
Who should ignore speed specs
If you print small, detailed parts such as miniatures, game pieces or jewellery prototypes, acceleration and cooling limit you long before top speed. Pick on reliability, noise and part quality instead.
Speed figures also mean little for multicolour work, where colour changes dominate time. Bambu Lab notes that flushing runs at the filament’s maximum volumetric speed, so a 0.2 mm nozzle makes each change noticeably slower than a 0.4 mm one [11].
Speed does matter if you print large, simple parts, such as storage bins or cosplay panels, or run several printers for sales. Then look for a published flow figure and high acceleration, not just mm/s.
- Ask for flow in mm³/s and the conditions it was measured under.
- Compare acceleration, not only top speed.
- Look for a recommended speed alongside the maximum.
- Treat speed-boat benchmarks as a best case for tiny parts.
Questions before you decide
Is a 600 mm/s printer twice as fast as a 300 mm/s one?
Rarely. Short moves do not reach top speed [8] and flow caps long ones. At 0.2 mm layers, 600 mm/s needs about 54 mm³/s of flow, more than the 32 mm³/s Bambu Lab publishes for the P1S [1].
What is volumetric flow and why does it matter?
It is how much plastic the hotend can melt per second. Divide it by layer height times line width to get the fastest the printer can extrude. OrcaSlicer calibrates it per filament [10].
Does input shaping make prints faster?
Not by itself. Klipper’s documentation says it has almost no effect on print time; it lets you raise acceleration without ringing, and acceleration is what changes time [9].
Which acceleration figure should I trust?
Treat the maximum as a ceiling. Klipper’s documentation says input shaping lets a printer raise acceleration without ringing, but pushing too far smooths fine detail [9], so detailed parts often print best below the spec-sheet figure.
Sources & verification
Product details and prices can change. Check the linked provider before buying.
- Bambu Lab Wiki: Unboxing P1S (includes P1S specification table) Accessed 30 Oct 2026
- Bambu Lab US store: A1 product page and specifications Accessed 30 Oct 2026
- Bambu Lab US store: A1 mini product page and specifications Accessed 30 Oct 2026
- Creality: K1C support page and parameters Accessed 30 Oct 2026
- Creality: K2 Plus Combo support page and parameters Accessed 30 Oct 2026
- Creality: Hi Combo support page and parameters Accessed 30 Oct 2026
- Creality: Ender-3 V3 SE support page and parameters Accessed 30 Oct 2026
- Klipper documentation: Kinematics Accessed 30 Oct 2026
- Klipper documentation: Resonance compensation Accessed 30 Oct 2026
- OrcaSlicer Wiki: Max volumetric speed calibration Accessed 30 Oct 2026
- Bambu Lab Wiki: Reduce waste during filament change Accessed 30 Oct 2026
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