Hey Steph - How Do You Auto Eject from CoreXY Printers?

We hear this question all the time: How exactly does auto ejection work on CoreXY printers?‍

Do we tilt them? How do we keep the machine balanced? And if tilting isn’t the trick, what’s the secret?

Let’s break it down. In this post, I’ll walk you through how our CoreXY auto-ejection system works, the thinking behind it, and why we chose this method over the obvious “just tilt it” approach.

The Challenge

Our very first auto-ejection setup was designed for bedslinger-style 3D printers—think Bambu A1 or Prusa MK3—where the bed slides forward and back while the toolhead moves in X, Y, and Z.

CoreXY printers are a different animal. Their bed travels only up and down, while the toolhead zips in every horizontal direction. That one mechanical difference makes all the difference for ejection.

Here’s why:

Bedslingers carry most of their weight toward the back, so tilting doesn’t threaten stability.

CoreXY printers, on the other hand, have an enclosed frame and a perfectly centered center of gravity.

If you try to tilt a CoreXY, you invite trouble—extra space requirements, interference with large spools or AMS units, and even the possibility of tripping sensors that shut the printer down. Since Bambu and other printer manufacturers already optimize these machines for precision, we didn’t want to add new failure points. Our mission was simple: eject parts without relying on gravity.

How It Works: The Flex-and-Push Sequence

Instead of tipping the entire printer, we rethought the process.

Our CoreXY system uses a flex sequence that gently bends the print bed to loosen the part. Right after that, the toolhead performs a carefully calibrated push to slide the print off—no violent fling into a corner, no jammed parts.

This approach not only keeps the machine’s footprint compact but also preserves the printer’s full build volume, so you can use every millimetre of your bed for production.

The Key To Reliability

The secret behind this consistency is the VAAPR surface. As you can see in the video below, it has incredibly high adhesion while hot but releases parts cleanly and effortlessly when cool.

The bed stays at 60 °C when the printer lifts. And yes - that really is a Post-it note our engineer places on the surface afterward (the release is that clean).

VAAPR doesn’t transfer particles, doesn’t wear out like PEI or G10, and comes with a lifetime guarantee against adhesion changes caused by manufacturing defects.

Wrapping Up

That’s the whole story of how we handle auto ejection on CoreXY printers - no tilting required. With the flex sequence and VAAPR surface working together, you get full build-volume access and true 24/7 production without extra moving parts. Simple, stable, and ready to print again.

It’s a straightforward system built for stability and non-stop printing. Print, eject, repeat.