How to vibe-code a 3D print: I let OpenAI's Codex adapt, slice and start a mask on my Bambu P2S

What I actually did

I printed a wearable Darth Nihilus mask on my Bambu Lab P2S without touching the slicer. I used OpenAI's Codex desktop app on Windows with its built-in Computer Use plugin, which lets Codex see your screen and click around your apps. It built a first version of the mask from photos, adapted an existing model when that version came out wrong, set up and sliced the print in Bambu Studio, sent it to the printer and then checked on it every 30 minutes through the printer camera.

From my first message to the print starting took about an hour, including one cancelled attempt. The printed mask is 3DMN's Darth Nihilus model from MakerWorld, which Codex resized and fitted with inside strap holders. Here's exactly how it went, so you can do the same with your own prints.

What you need

The Codex desktop app, signed in with your ChatGPT account, with the Computer Use plugin available. You call it in a message by typing @Computer.

Bambu Studio installed, signed in and connected to your printer. This matters: because Codex works the normal Bambu Studio buttons, it sends prints the supported way. You don't need Developer Mode or any third-party printer software.

A MakerWorld account if you plan to start from an existing model, and filament loaded in the AMS so you know which slot to tell it to use.

Step 1: Give it photos and real dimensions

I attached three product photos of a resin replica mask, one of which listed its size, and wrote: "I want to print this on my bambu labs p2s. Can you make a 3d model and a printable file with the dimensions shown." Codex built a curved mask at 215 by 180 mm, checked that the mesh was one closed solid and exported an STL and a Bambu Studio 3MF.

Then add the requirements a product photo can't tell it. I asked for strap holders so I could wear it, then asked for them on the inside, said it had to fit my printer and that I was printing in white. Codex moved the holders inside, sized them for 20 mm webbing and confirmed the model fit the P2S's 256 mm build volume.

Ask it how confident it is. When I asked, it said it trusted the printer fit but not the face fit or strap strength, and made two small test pieces, a strap-holder section of about 7 g and an eye-fit section of about 27 g, so I could check before spending a full spool's worth of time.

Step 2: Check the design yourself

This is the step you can't skip. When I asked Codex to make it exact, it traced the outline, eye openings and forehead markings from my photo and was upfront that depth and curvature were only estimates, since a photo doesn't contain them. Even so, I spotted that the two round ornaments down the middle were off centre. Codex fixed it in a minute once I pointed it out, but it hadn't caught it on its own.

If you're copying an existing object, building from photos gets you close, not exact. For anything decorative where details matter, an existing model is usually the better starting point.

Step 3: Or start from an existing model and let it adapt it

I sent Codex a link to 3DMN's Darth Nihilus mask on MakerWorld and said I wanted mine wearable. Two snags: MakerWorld needs a login to download, and Codex is designed not to type passwords for you, so I signed in myself. Then Computer Use stopped once because it couldn't confirm the browser's address. I replied "Try again" and it opened the model straight in Bambu Studio.

Codex found the model was about 183 by 154 mm with a hollow back, scaled it to my 215 by 180 mm, added two inside loops for a 20 mm strap and re-checked that it was still one closed solid. 3DMN's model is licensed CC BY-NC 4.0, which allows personal, non-commercial adaptations like this as long as you credit the designer. Check the licence on anything you adapt.

Step 4: Let it set up and slice

With the model open in Bambu Studio, I typed: "@Computer can you set up the profile and slice it the way you think will work best based on research online." Codex worked through the settings, citing Bambu's P2S manual for the support choices.

For white PETG on the 0.4 mm nozzle and textured plate, it chose 0.16 mm layers, four walls, six top and bottom layers, 15% gyroid infill and an 8 mm brim. It used 245 °C for the first layer and 250 °C after, a 70 °C bed, the auxiliary fan off, and tree supports with a 0.24 mm gap so they'd come off more easily.

I asked it to try PLA for the support contact layers, a common trick for easy removal. It compared the options but couldn't reliably edit Bambu Studio's purge settings, which open in a pop-up the tool struggled to click, so it kept PETG supports rather than risk mixed material in the mask. That's the right call, and a good example of where these tools still hit walls.

Step 5: Send the print

I said "Go ahead and print it" and Codex sent the job from Bambu Studio to the P2S, picked white PETG in AMS slot A3 and left bed levelling and flow calibration on. Bambu Studio estimated 17 hours 35 minutes and 207 g, including 45 g of supports.

One habit worth copying: tell it exactly when it's allowed to start a print. My first job was cancelled a minute after it started because I'd spotted the off-centre ornaments. Starting a print is the expensive, hard-to-undo step, so make the go-ahead your decision.

Step 6: Let it babysit (but don't rely on it)

I asked Codex to check on the print every so often. It set up a check every 30 minutes, opened the camera view in Bambu Studio and reported the layer, the time left and anything it could see, like stringing and a rough edge near the supports. For fun, it also set up an unlisted YouTube stream of the print in OBS with Star Wars music, and asked me to confirm before going live, with a warning that copyrighted music can get a stream muted.

It has limits. Overnight, an edge started curling where it met the supports. Codex first read my photo as a normal gap and only told me to pause once I mentioned the curl, and said its first answer had been too reassuring. When Bambu Studio was hidden behind another window it couldn't see the camera at all. Treat AI monitoring as a second pair of eyes, not a replacement for checking the first layer and keeping a smoke alarm nearby.

What I'd do differently

Dry the PETG first. The mask came out with fine stringing across the openings that pulled off by hand, and Bambu's own guide says moisture makes PETG stringing worse. My stringing guide at petg stringing fixes covers the fixes.

Print the small fit tests Codex offers before the full job, and pick the model source first. Starting from a good existing model saved more time than any setting change.

Prompts to copy

Design: "Make a printable 3D model of this for my Bambu Lab P2S at [height] by [width] mm. Add [strap holders, mounting holes, etc.] on the [inside/back]. Check it's one closed solid and fits the build plate."

Confidence check: "How confident are you in the fit and strength? Make small test pieces I can print first."

Slicing: "@Computer set up the profile for [filament] in AMS slot [x] and slice it the way you think will work best based on research online. Tell me the time and filament estimate before printing."

Monitoring: "Check on the print every 30 minutes through the camera and tell me about stringing, lifting, detachment or errors."

Other ways to do it

Claude can control your desktop apps the same way through its computer use feature, and there are free tools like an OpenSCAD MCP server that let an AI write and preview CAD code. XDA's head-to-head found Claude and GPT both still get sizes or orientation wrong, which matches my experience: check the model yourself. If you share an AI-made model on MakerWorld, it needs the AIGC tag.

From a tech standpoint

Letting Codex drive Bambu Studio turned a 17-hour print into a conversation. It handled the slicing research, settings and sending without me opening a single menu. It still needed me for logins, for spotting design mistakes and for judging when something on the print bed looked wrong. Use it as a fast, tireless assistant, keep the final say on what prints, and you'll get more done with your printer than you thought you could.