What input shaping does on the Creality K1 and K2

Input shaping is what stops your K1 or K2 from leaving wobble lines on every fast print. The toolhead is moving quickly enough that the gantry rings like a struck tuning fork, and the firmware actively cancels that ringing before it can show up on the part.

What input shaping actually does

When the printhead changes direction at speed, the whole gantry vibrates. That tiny wobble shows up on the print as ghosting. You see faint echoes of corners, holes or embossed letters repeated a few millimetres further along the wall.

Input shaping cancels that wobble at the source. The firmware knows roughly when each ring will arrive and nudges the motors slightly out of phase so the two waves cancel each other out. You get the speed without the smear.

The K1 and K2 push the toolhead at speeds that would shake a basic Ender to pieces. Without input shaping, those speeds would be unusable. With it, the printer can run at 300 to 600 mm/s and still hold a clean wall.

How the K1 and K2 calibrate it

Both printers carry an accelerometer on the toolhead. You do not have to install one, wire one up, or run a separate macro. The chip is already there, soldered to the toolhead PCB.

When you run the resonance test from the screen, the printer shakes the gantry through a sweep of frequencies on each axis. The accelerometer records what comes back. The firmware then picks the shaping filter and the frequency that flatten the response.

On the K1 you find it under Settings, then Device, then Self-Check, then Vibration Compensation. On the K2 it sits in a similar menu under the maintenance section. The whole sweep takes a few minutes. You will hear it. It sounds like a small angry insect trapped inside the chassis. That is normal.

When you should recalibrate

Factory calibration is fine for most owners out of the box. Rerun it only if one of these is true:

• You moved or reseated the toolhead, hotend, or gantry.
• You added mass to the toolhead, such as a different hotend, a fan duct, or a webcam mount.
• The printer has been shipped, dropped, or knocked hard.
• Ghosting has appeared where it was not there before.
• You changed belt tension or replaced a belt.

Anything that changes the mass of the moving parts, or the stiffness of the frame, changes the resonance frequency. The shaper has to be told what the new numbers are. The K1 and K2 do not auto-rerun shaping between jobs. They store the result and reuse it until you say otherwise.

Can you do it yourself?

Yes. The on-screen calibration is the whole job for most owners. You do not need to flash custom firmware, edit a config file, or open a terminal unless you are deep into modding.

Before you hit the calibrate button, do these in order. They cost nothing and they fix half the ghosting we see come across the bench.

1. Tighten the belts. Slack belts give false resonance readings. Both belts should pluck at roughly the same pitch. 2. Check that nothing rattles on the toolhead. A loose fan shroud will add its own buzz on top of the gantry's. 3. Make sure the printer is on a firm surface. A wobbly desk reads as a wobbly gantry. 4. Then run the on-screen vibration compensation.

If the calibration completes but ghosting is still bad, the problem is almost never input shaping. It is usually belt tension, a loose eccentric nut, or a worn V-wheel.

If you have rooted the K1 and moved to mainline Klipper, the procedure is different. You will be running SHAPER_CALIBRATE per axis and reading the PNG output. That is not stock behaviour and is outside the scope of this article. If you are at that point, you know where the Klipper docs live.

K1 versus K2

Both use the same idea on different mechanics. The K1 is a corexy with a relatively light gantry. Its first-axis resonance usually sits in the 40 to 65 Hz range. The K2 is a heavier machine with a larger build volume. Frequencies tend to come in lower and the firmware leans harder on the shaper to hold the higher speeds.

The K2 Plus also has an AI camera for first-layer and spaghetti detection. Do not confuse that with input shaping. The camera does not help vibration. The accelerometer does not help failure detection. Two separate systems doing two separate jobs.

What if the calibration fails?

The most common error is the accelerometer not responding. On a stock K1 or K2 this usually means the ribbon cable to the toolhead is loose or damaged. Power off, reseat the connector at both ends, and try again.

If it still fails, the toolhead PCB or the accelerometer chip itself may be at fault. That is a board-level repair.

A second failure mode is the calibration completing but reporting frequencies that look wrong. Either too low, or wildly different between the X and Y axes. That points to mechanical play. Tighten everything before you blame the electronics.

Symptoms that look like vibration but are not

A few things ghost in ways that mimic input shaping problems. Knowing the difference saves you running calibrations that will not help.

Layer shift looks like ghosting at first glance, but it is a sudden offset of every layer above a single point, not a faded echo. That is a skipped step or a slipped belt, not the shaper.

Pressure advance artefacts, like bulgy corners and thin walls just after a corner, are sometimes mistaken for ringing. They come from filament flow, not vibration, and you tune them with the pressure advance test instead.

Wet filament leaves a rough, fuzzy surface. The clean repeat pattern of ghosting will not be there. Dry the spool before you touch the shaper.

When to mail it in

If the on-screen calibration keeps failing, the accelerometer reads zero on one axis, or the toolhead board is throwing communication errors, the next step is bench work. We diagnose K1 and K2 toolhead PCBs in the workshop. Usually it is a damaged ribbon, a cracked solder joint at the connector, or a dead accelerometer chip. We will tell you within a few working days whether it is fixable or whether the board needs replacing.

Send it in through the form at /contact.html. Include a short note about what the calibration screen reported and what you have already tried. Mail-in only. We will share the workshop address once a booking is confirmed.