Monolith Gantry R1: a shorter belt path for Voron 2.4 and Trident

A gantry, not a printer, and the belt path is the whole point

This is a performance-oriented, configurable gantry platform for the Voron 2.4 and Trident. That scoping matters. It is not a printer design and it is not a new machine, it is the motion system that replaces the one your Voron came with, and every claim in the README is a claim about that system. The design goals list is short and consistent. The shortest and simplest belt path possible, with AWD compatibility. The shortest moment arms possible, for increased rigidity even when reusing hardware and motion parts. Double shear steppers and live shaft idlers for higher belt tensions and better reliability. A design that looks good. And a cheap bill of parts. The first two goals are the same goal stated twice, which tells you that geometry is the whole design rather than one factor among several.

The variants, and what the configurator decides

The configuration axes are listed in the README. Drive configurations are 2WD or AWD, and belt widths are 6mm or 9mm, with build options covering printed, sheet metal, or milled kits. Those axes interact, and the README says as much in the R1 changes, where one of the listed improvements is more shared parts between the 6mm and 9mm versions, which suggests the design was brought closer together across belt widths. The configurator is the tool that turns your choices into files and a selected parts list, and the README points at it for configuration, files and the selected BOM, with build guides and assembly notes in the Docs directory and a separate FAQ for configuration, sourcing and assembly questions. A gantry design has a large number of interacting options, and a configurator that emits the selected BOM is how you avoid discovering at the parts stage that your combination was not supported.

What the R1 revision changed

The R1 notes list what changed relative to earlier versions, and it is a mix of mechanical and ergonomic improvements. Updated styling, so it does not look like a spreadsheet. More shared parts between the 6mm and 9mm versions, which lowers the cost of switching belt width. Sheet metal options, which is the direction the design has moved. It can fit into a stock 2020 frame, at the cost of some Y-overtravel, with an added no-protrusion mode for people who need the frame unobstructed. Much better tensioner travel, which is a real annoyance on a stock machine and a common reason people replace gantries. And no toothed idlers, which removes a part and a source of alignment problems. The stock-frame point is the one that decides the purchase for many people, since it means the modification is reversible in the sense that you can put the original back.

The performance numbers, and the condition attached to them

The performance expectations section is written in the conditional, which is the useful part. For 2WD, the 10 to 15 centimetre shorter belt path and the stiffer and lighter XY joints mean the printer should perform similarly to a 50mm smaller one with the same X-axis setup. For AWD, and this is the claim to note, the shortened path does not come at the cost of 20 centimetres of belt length and idlers, so input shaper scaling can be close to plus 100 percent compared with 2WD, because the effective belt length is halved. The condition is stated in the same sentence: only when no toolhead or frame bottlenecks are limiting its scaling. And 9mm belts can offer an additional 50 percent input shaper scaling on top of that. So the ceiling is real and conditional, and the condition is the same in both cases, which is a sign the author has been careful about how the numbers are read.

The catch list, which is more useful than the performance list

There is a section headed what is the catch, and it should be the first thing you read. You have to build a well-balanced system, because the increased effective belt stiffness in the higher-end gantry configurations will amplify toolhead and frame rigidity issues. Some toolheads are not yet compatible because of the different belt path. A Z-chain relocation or a Z-umbilical is needed on the V2. And the Trident rear vertical extrusion brackets have to be rotated by 180 degrees or swapped to regular 2020 brackets depending on the gantry configuration. Each of those is a specific, checkable consequence, and together they describe a project that is mechanical work rather than a bolt-on. The toolhead compatibility point in particular is why a separate toolheads repository exists, with compatible toolheads, belt clamps and design guidelines, and it is worth reading before you assume the toolhead you have will work.

Sheet metal is a different order of build, and the guides are not there yet

The README opens with a notice that has to be taken at face value. Step-by-step build guides for the printed and sheet metal versions are not yet available, and the sheet metal version is more difficult to build than what the average Voron user is used to, with a request to evaluate the required patience and skill levels before proceeding. The paths that do exist are a configurator, a docs directory with build guides and assembly notes, a toolheads repository, and an FAQ. The build guide is a video link and the installation guide is a separate video link, which is how the majority of the community consumes assembly instructions for this kind of project. A milling and sheet metal build for a printer gantry is a genuinely different activity from printing parts, and the README's framing is that you should decide whether you are the person for it before starting rather than halfway through.

The repository is a design package, licensed for non-commercial use

The repository contents are what you would expect from a mechanical design package. There is a BOM directory, a CAD directory, a DXFs directory with the flat patterns, an STLs directory with the printed parts, a Docs directory, a UserMods directory for the configuration files that go onto the machine, an Images directory and a FAQ. The README is also the place where the project points at its official milled gantry kits in a separate repository, and it asks people to join a dedicated Discord server for support and current information, with a Patreon link for those who want to support more projects like it. The licence is the thing to check before you build or sell anything with it. The work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International Licence, so the non-commercial term applies to the design, and GitHub reports the repository licence as one it cannot classify, so the LICENSE file at the root is the authority on the terms. The repository is not archived, with the last push on 2026-10-08.

Editorial conclusion

Monolith Gantry fits an existing Voron 2.4 or Trident owner who has already exhausted the printer's stock motion system and wants a shorter, stiffer belt path with room to scale input shaping. It does not fit a first-time builder, since the README warns that the sheet metal version is harder to build than the average Voron user is used to and that step-by-step guides are not yet available. Verify first that your printer's revision is one of the supported ones and that your toolhead and frame can take the new path, and read the catch list before ordering parts, because the rigidity gains only build in a balanced system.

Frequently asked questions

Official sources

1. Issues
2. Monolith3D/Monolith_Gantry on GitHub
3. README