YOU CAN BUILD A 3D PRINTER THAT PRINTS IN SOLID STEEL
Instead of an eighty-thousand-dollar laser system, this machine prints solid steel parts by stacking weld beads on a gantry.
by Cranktown City
WorkshopOpen-hardware
- difficulty
- ●●●●●
- time
- several weekends
- license
- license not specified
- repo
- repo 0 stars
●●●●● · several weekends · license not specified · 0 stars · repo
Partner
COMPAREE VERDICT
This is a real machine that prints real steel parts, and it is also a project with no published files, no BOM, and no step-by-step assembly guide beyond what you can see in the video. You are building from observation, and you need to know welding, motion control, and 3D printer electronics before you start. The core idea is simple: a MIG welder replaces the extruder on a gantry, the torch trigger is wired where a heater would be, and the machine stacks weld beads until the part exists. What makes it hard is everything around that idea. The enclosure must block UV, sparks, and spatter. The fume extraction must actually work. The motion system must be stiff enough that the torch does not wander under the weight and vibration of the weld. The most likely failure is underestimating the safety: a welding arc emits UV-C strong enough to cause arc eye from reflection alone, and running this open or without extraction will injure you. The second most likely failure is believing the parts will come out usable as-printed. They will not. A weld bead is millimetres wide, layers are visible, and most parts need machining before they are a functional surface. What you get is a solid steel part made in a home workshop. If that is worth reverse-engineering a video and building the safety infrastructure, this is a genuine path to metal additive manufacturing outside industrial pricing.
IN THE REPO
NOT IN THE REPO
- —No repository, BOM, CAD files, or firmware is provided in the payload.
- —The build is documented step by step in a YouTube video by Cranktown City, including failed tests.
- —No licence information is available; cannot determine commercial use restrictions.
- —The video shows the machine working, but there is no parts list, no drawings, and no published G-code workflow.
- —You are reverse-engineering from the video and your own knowledge of welding, motion control, and 3D printing.
- —The enclosure, fume extraction, and electrical safety are mandatory, not optional — a welding arc will burn eyes and skin from across a room.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
Partner · KickstarterHeyGears G1: 10M+ colors and transparent parts in one print, plus UV printing on flat objects. Figures, parts and labels — no painting.
Videos
Operátor (custom téma)
The build is shown working, including failed tests, but there is no voice-over parts list or assembly sequence — you are watching and inferring.
Gallery
Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Watch the full video and take notes on the gantry design, the torch mounting, and the enclosure. (There is no published design, so you are reverse-engineering from what you see.)
- 2.Choose your motion platform: build a custom gantry or adapt an existing large-format 3D printer frame.(The gantry must be stiff enough to hold position under the weight and vibration of the welding torch.)
- 3.Select a MIG welder and confirm it can be triggered by a low-voltage signal or relay.(Most MIG welders can be triggered via their torch switch; you will wire that circuit to a relay controlled by the stepper board.)
- 4.Wire the stepper board (RAMPS, SKR, or equivalent) and configure the firmware to treat the torch trigger as an extruder heater or fan output.(This is standard 3D printer electronics, but you are controlling a welder instead of a hot end.)
- 5.Build or buy a proper welding enclosure with UV-blocking panels and fume extraction before you run a single test bead.(The safety infrastructure is not optional.)
KNOWN ISSUES
- Underestimating the safety: a welding arc will cause arc eye (photokeratitis) from reflection alone, and fume exposure is cumulative and toxic. The enclosure and extraction are not features, they are prerequisites.
- Believing you can skip the welding experience. If you cannot lay a clean bead by hand, you will not be able to tune the machine to do it for you.
- Expecting precision. A weld bead is millimetres wide and layers are visible. Parts come out rough and almost always need machining to be usable.
- Building a gantry that flexes under the weight or vibration of the torch. The motion system must be stiffer than a plastic printer because the forces are higher and the tolerances are worse.
- Not having a tested workflow for generating toolpaths. You need to slice a model, convert it to G-code that moves the torch and triggers the weld at the right moments, and tune feed rate, travel speed, and dwell times by trial.
- Running this indoors without adequate ventilation. Welding fumes are not just unpleasant, they are a respiratory hazard, and the volume produced by continuous printing is significant.
Is there a BOM or a parts list?
No. The video shows the machine working, but there is no published BOM, no CAD files, and no step-by-step build guide. You are reverse-engineering from observation.
Can I use this to replace machining?
No. Parts come out rough, with visible layers and millimetre-scale bead width. Most parts need machining after printing to reach a usable surface. This is additive manufacturing that still requires subtractive finishing.
Do I need a commercial metal 3D printer license or certification to run this?
There is no licensing requirement for the machine itself, but welding generates hazards (UV, fumes, fire risk) that require proper safety measures. In some jurisdictions, commercial welding or operating extraction systems may require permits or inspections.
What can I actually print?
Anything you can model and slice, within the build volume and the resolution limits of a weld bead. Common targets are brackets, fixtures, mounts, and structural parts where appearance does not matter and strength does.
Community builds
No community builds yet — be the first, we feature the best ones.
Discussion1
FROM THE COMPAREE TEAM
Entry-level DMLS systems start at eighty thousand dollars, and this build gets to solid steel for the cost of a welder and a gantry. What would you print first if surface finish did not matter and strength did?
Cranktown City
Cranktown City documented this build step by step on YouTube, including the tests that did not work. No other public information about the creator or their background is provided in the payload.
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DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM7d ago
Practical notes from our verification: there is no repository, no BOM, and no published CAD. The video shows the machine working and includes failed tests, which is rare and honest, but you are building from observation. The single biggest decision is whether you already know how to weld — if you do not, this is the wrong project to learn on. The second biggest decision is the safety infrastructure: the enclosure, extraction, and shielding are not optional, and the cost of doing them properly is a significant fraction of the total budget. If you have the welding experience and the space to run this safely, it is a genuine route to metal additive manufacturing outside industrial pricing. If you do not, it is a way to injure yourself expensively.