DuelingZero
Dueling Zero - a Dual Gantry V0 mod. Enable dual-color, dual-material, and even multi-part printing... with the same speed and quality as single-extruder printing.
Install / Use
/learn @zruncho3d/DuelingZeroREADME
Dueling Zero - a Dual Gantry V0 mod
Two extruders. No compromises.
Enable dual-color, dual-material, and dual-part printing... with the same speed and quality as single-extruder printing.
Mod a Voron Zero or build one fresh!
D0 is the only open-source, fully-documented, reproducible-by-anyone Dual Gantry printer out there.
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In a Dual Gantry printer, the two heads are fully independent. With no extra weight to drag around (vs an IDEX printer), and no complexity added to switch between heads (vs a toolchanger), Dual Gantry is a promising way to do more with a 3D printer.
Curious? Watch the first one print below!
> > > Watch Video from first prints
(original v1 gantry shown)
What's Here?
Tons of content. On this page:
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Releases: Visual release notes
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Overview: Why Dual Gantry?
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Sample Builds: Parts and sizes
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Links, Credits, and Support
... and beyond, split into their own pages:
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Parts: Parts list to build your own
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Instructions: Instructions to print, assemble, and configure
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Software: Two toolheads in one workspace, explained
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FAQ: Common questions, answered
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Archived v1: Prior design
Enjoy! I hope this project inspires you to build something new, whether a D0 or your own design. -Z
Releases
2023-09-16 v3 Gantry release and updates
This release moves to a completely-new, symmetric, nested belt path:
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The new Pandora's Box-derived gantry design, created in close collaboration with Desune on Discord, has far fewer unique parts, adds travel, and enables wider toolhead compatibility.
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Here's the side-by-side comparison from above, with v1 on left, and new v3 on right:
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Or, in reality:
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The printer looks a little different now, with internal spool holders!
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In short - this is a big update. This is what D0 should have always been.
Sometimes it's only through iteration and collaboration that you get to what feels right. The v3 gantry feels right. No weird strut, no flipped motors, smaller, more maintainable... all-around, better. See the comparison table on the Design page for more details on why.
Other improvements:
- Boop support for perfect first layers every time, nozzle probing with Boop is now the default. There are no magnets to get loose in a heated chamber and no probe motions to configure anymore.
- Better toolhead compatibility, including a Voron 0.2-compatible mount for the Voron Mini Stealthburner toolhead and many others.
- Gantry board support for the GBB15 gantry board - enables super-clean, easy wiring with magnetic-attach covers.
- Dual internal spool holders added, reducing the effective width.
Existing v1 builders: to upgrade, the main costs will be new rails, a few new extrusions, and Boop parts. There's nothing wrong with your v1 build; it will print fine. But if you want more travel and the benefits of Boop, a fresh rebuild with the new larger default frame size might make sense.
For earlier releases, see the Updates page.
Overview
What’s a Dual Gantry printer?
Dual Gantry is a rare 3D printer type with two toolheads moved by two completely independent XY motion systems:
Yes, you’re seeing double, with black and silver toolheads in a dual-CoreXY motion configuration.
Why a Dual Gantry printer?
In general, a second hotend adds enormous flexibility - to support two colors, two materials (typically support + main), and two nozzle sizes, in one print, with no color-bleed issues, cross-contamination, or wasteful purging. Sounds good, right!
Well, that second hotend, if mounted on a single toolhead, can get in the way of print quality, as it drools filament when not in use - and the toolhead is now custom. :frowning:
So along comes IDEX, short for Independent Dual Extrusion, which adds a second, independent toolhead on a shared axis (typically the X axis). Sounds better, right?
No drool, plus something cooler: one printer can now print two identical parts simultaneously, in mirror or duplicate modes. :muscle: (note: in theory; depends on firmware support)
Open-source IDEX designs include Voron-derived ones, like Zruncho’s Double Dragon, Eddietheengineer's Tridex, and Ankurv’s IDEX Switchwire. There's also the Muldex, and there's no shortage of commercial examples, too: Sovol SV04, FlashForge Creator Pro, BCN Sigma, Jadelabo J1, and many more.
But that second toolhead comes at a cost: moving mass, which has effects on print speed (max accel) and quality (typically, ringing artifacts). :neutral_face:
Simplify, then add lightness - famous quote from Colin Chapman at Lotus
Whether building a fast race car or a fast printer, physics can't be ignored.
You can mitigate the moving mass somewhat, by using a lighter toolhead, typically with a remote Bowden extruder, but Bowden extruders introduce their own tuning challenges.
With Dual Gantry, you get a no-mass-added gantry for the common case of single-extruder prints. Unlike an IDEX, here, each toolhead is truly independent and can move in X and Y on its own - potentially to print two completely different objects at once!
There’s no hit to max acceleration or potential for ringing caused by dragging around a heavy second toolhead on a longer rail all the time.
Sure, you can't print more than two colors, like a multi-material unit or toolchanger can, but everything in engineering is tradeoffs... and Dual Gantry is an interesting and new point in the broader space of 3D printer types that support multiple extrusion:
Take a look at the table above, or at this other helpful categorization. This diagram is not comprehensive, but gives a sense for the depth of the design space, and especially, the rarity of everything not on the far left side (typical single-extruder printer). For some interesting points in the design space, there's only one commercial example!
(Please file an issue on GitHub if you know of any significant omissions.)
What’s the catch?
On the plus side, you don't have to design it (anymore). You don't need to program the firmware either (anymore): Klipper works (thanks to a collaboration with tircown) and RepRapFirmware supports two active gantries, out-of-the-box. The software base needed to make full use of the workspace, by implementing collision detection and avoidance, is the src folder here and explained in the Software section.
On the minus side, building it is roughly twice the work of a typical printer. There are added costs from the second gantry and toolhead. There are alignment challenges - including XY and YZ skew calibration - which are currently unknown. And like any multi-head printer, you'll have more tuning and slicer stuff to figure out.
If all that sounds daunting, this is not the printer for you. If being the first to figure these out sounds exciting, this may be your next printer!
How does this mod work?
Roughly... start with a Pandora's Box gantry. Turn it 90 degrees. Add extra bearing stacks and combine idlers with AB blocks. Duplicate it about the center. Flip it upside-down. Add off-the-shelf Boop and toolheads.
That’s the core idea.
In practice, though, there are quite a few additional bits to design to make it work. And like any V0 mod, the devil is in the packaging details: every mm matters.
Beyond the gantry, D0 heavily leverages off-the-shelf parts from these repos:
