Guided setup

AUTO_EJECT_SETUP sets everything up in five short dialogs inside Mainsail or Fluidd. You press buttons; there are no files to edit and nothing to measure with a ruler.

AUTO_EJECT_SETUP

In short (Voron Tap, parts falling off the front):

1. Set the blade 1.5 mm above the nozzle tip with hardware/test/blade_gauge.stl. Print hardware/test/calibration_block.stl with 100 % infill, away from the middle of the bed, and leave it there. Measure right after the print, while it is warm and well stuck.
2. Run AUTO_EJECT_SETUP and press Start, then Front.
3. Clear everything else off the bed and press Bed is clear - move. The toolhead goes to the block by itself. Press Measure and wait 2–3 minutes, then Next.
4. Press the width of your blade: 60 mm, 80 mm or 100 mm.
5. Take the block off, press Bed is clear - move and check that the blade is past the edge of the sheet. Press Yes, it is past the edge.
6. Pick a temperature (32 C for PLA), press Save, then Dry test.

Every screen is shown below with a picture.

Before you start

• The blade is mounted on the toolhead.
• With a probe that touches with the nozzle (Voron Tap and similar): print hardware/test/calibration_block.stl (20 × 20 × 3.5 mm) anywhere but the middle of the bed and leave it stuck there. The blade's lower edge should sit 1–2 mm above the nozzle tip. The wizard then measures the blade by itself.
• With other probes: a small block with a flat side, such as a 20 mm calibration cube.
• printer.cfg has a [respond] section (the dialogs need it) and, ideally, [save_variables] so the results survive a restart.
• A recent Mainsail or Fluidd. Both show Klipper's action:prompt dialogs.

The steps

Five short screens. Each picture shows the dialog on the left and what to do at the printer on the right. The highlighted button is the one to press.

Start

Type AUTO_EJECT_SETUP in the console and press Enter. The first screen lists anything missing from printer.cfg. If it says all OK, press Start.

1. Drop edge

Choose the edge the parts should fall off and put a box under it. On a CoreXY printer that is usually the front, on a bed slinger left or right.

2. Measure the blade

Clear the bed, but leave the printed calibration block, and press Bed is clear - move. The toolhead homes around the block and stops 5 cm above it (or above the middle of the bed, if no block was printed).

With Voron Tap or another probe that touches with the nozzle, press Measure. The probe finds the blade by itself in 2–3 minutes (how).

Why a low, printed block? The fan duct under the toolhead sits only a few millimetres above the nozzle tip. On a tall block it would touch the block before the blade does, and a loose block slides when it is touched. A 3.5 mm block stuck to the bed avoids both. Without a printed block, tape a flat piece 2–6 mm tall under the nozzle.

When it is done, press Next. If it says Could not measure, the reason is on the screen: fix it and press Try again, or press Measure by hand. If the blade is on the other side of the nozzle from the drop edge you chose, it says so and names the edge to choose.

Other probes (BLTouch, inductive, eddy current) measure by hand instead: jog Z until the blade is about 2 mm above the bed, then touch the block with the blade and with the nozzle. The screens tell you each move.

3. Blade width

Press the size of the blade you printed. For another size, use -10 / +10, then Use.

4. Edge check

Take the block off the bed and press Bed is clear - move. The toolhead goes to the drop edge and lowers the blade. Look from the side: the blade must be past the edge of the sheet, or the parts would stay on the bed.

5. Save

Pick the bed temperature at which your parts let go (32 °C is a good start for PLA), press Save, then Dry test to watch the path traced 2 cm above the bed. The push current is set for you, to 60 % of your motors' run_current.

Your first real eject

After that, put AUTO_EJECT HEIGHT=[max_layer_z] HOME=1 in your slicer's end G-code, after your end macro (slicer-setup.md), and the printer clears the bed after every print.

Automatic blade measurement

With a probe that touches with the nozzle, such as Voron Tap, anything that pushes the toolhead up triggers the probe, the blade included. The wizard uses that to measure the blade against the printed calibration block (hardware/test/calibration_block.stl, 20 × 20 × 3.5 mm) stuck to the bed:

1. The nozzle finds the block: it touches the top, then steps off the front and rear edges, halving the step each time, to find where they are.
2. The blade lands on the block: with the nozzle behind the block, only the blade can touch it. The difference to the block height is how far the blade's lower edge sits above the nozzle tip (blade_lift).
3. Step back until the blade misses: the point where the blade comes off the rear edge gives the distance from the nozzle to the blade face (blade_offset), to about ±0.5 mm.

It takes about 25 touches, or 2–3 minutes. push_z is then set so the blade's lower edge runs blade_clearance (1 mm) above the bed, but never with the nozzle below push_z_min.

To measure again later, for example after moving the blade in its slots:

AUTO_EJECT_CALIBRATE

It saves only push_z, blade_offset and blade_lift. The block must stay put: print it with 100 % infill, leave it stuck to the bed, and measure while the bed is still warm (55 °C at most). It is low on purpose: on a taller block the fan duct under the toolhead touches it before the blade does. The blade's lower edge must be 1–2 mm above the nozzle tip. If something does not fit, the measurement stops and the dialog says why (troubleshooting). Nothing is changed until you click Use these values.

Where the values go

• With [save_variables]: saved as auto_eject_<setting> and applied one second after every start. Saved values override auto_eject_settings.cfg.
• Without [save_variables]: applied until the next restart, and the dialog lists the lines to copy into auto_eject_settings.cfg.

To go back to the values in auto_eject_settings.cfg:

AUTO_EJECT_SETUP STEP=reset
FIRMWARE_RESTART

Tips

• You can run the setup again at any time. It starts from your current settings.
• When measuring by hand, the jog buttons label directions as toward edge and away, so they mean the same thing whichever drop edge you chose.
• If the blade offset comes out below 1 mm or above 200 mm, the wizard asks you to measure again. This usually means the nozzle was moved the wrong way.