The Prusa XL is built around one of the more ambitious ideas in desktop 3D printing: a toolchanging system that parks up to five independent toolheads and swaps between them automatically, mid-print, so a single job can mix materials and colors. For most owners that system is the whole point. For Jón Schone of Proper Printing, it was a starting point. In I Replaced All 5 Prusa XL Tools With My Own Belt Driven Extruder, he pulls out the factory toolheads and fits the machine with five of his own belt-driven extruders instead.
What the video covers
The build replaces each of the XL’s five tool positions with a version of Schone’s own “Proper Extruder,” a belt-driven design he has developed across earlier projects. Where the stock XL toolhead uses Prusa’s geared “Nextruder,” a belt-driven extruder grips the filament between a pair of moving belts rather than between toothed gears — an approach Schone has tuned specifically for soft, flexible materials. Adapting it to all five positions on a commercial toolchanger means working with the printer’s mechanics, its electronics, and the toolchanging routine that has to pick up and set down each head reliably.
It is the kind of deep modification almost no owner would attempt, which is what makes it a useful watch. You get a clear window into how the XL’s tool system is actually put together, and where a determined maker can push past the stock hardware — including the problem-solving that comes with bending a polished commercial platform to a homebrew design.
The bigger picture: why someone mods a printer like this
The XL was Prusa’s first CoreXY machine, and its headline feature is the toolchanger: each head is a self-contained extruder with its own electronics, and the printer can swap heads automatically to combine, say, a flexible material, a rigid one, and a third for dissolvable or break-away supports in a single print. Prusa positions all five heads sharing one large build volume as the platform’s main advantage over a single multi-material hotend.
So why rip that out? The honest answer is that this is an engineering exercise more than a practical upgrade. But there is a real technical thread underneath it. Flexible filaments such as TPU are notoriously awkward to feed: a soft strand can buckle or get chewed in a conventional geared extruder. Belt-driven extruders aim to fix that by supporting the filament along a longer length between two belts, guiding it smoothly toward the hotend — a concept makers have explored precisely because it handles flexibles more gently than gear drives. Putting five of those on a toolchanger is Schone asking how far his own design can scale on someone else’s hardware.
What to watch for
- Toolchange reliability. The hardest part of any toolchanger mod is keeping pickups and drop-offs repeatable. Watch how the custom heads behave through repeated swaps, not just on a single print.
- Flexible-filament performance. The belt-driven approach is built for soft materials, so the interesting comparison is how it feeds TPU and similar filaments versus the stock geared head.
- Treat results as one maker’s findings. Any speed, quality, or reliability outcomes shown are Schone’s own results on a one-off build, not independently tested specs. Take them as a demonstration, not a benchmark.
- It’s a project, not a product. This is a research-style mod. Don’t read it as a recommendation to modify your own XL — the stock toolheads exist for good reasons.
More from Proper Printing
If this is your first time on the channel, start with the build that put it on the map: We 3D Printed a Kayak in ONE PIECE on a Treadmill and tested it! Working with Ivan Miranda — whose treadmill-bed printer drove the build — Schone helped repurpose a treadmill into an oversized “infinite-Y” belt printer, using the moving treadmill belt as a continuously advancing print bed to produce a full-sized kayak in a single piece. They did take it out on the water, and it floated — but the result was barely usable, too narrow to paddle safely. That is the same instinct as the XL build: chase an idea well past the point of practicality to find out exactly where it breaks down.
Credit: All footage by Jón Schone / Proper Printing — we summarize and embed creators’ work to point you to the original. Any performance figures shown are the creator’s own results, not independently verified specs. Watch the full videos and subscribe on Proper Printing’s YouTube channel.
