You can make a perfect-fit Gridfinity insert from a photo in about 5 minutes, with no CAD software and no calipers. Place your object on a printed calibration board, take one photo, and Snapfinity's computer vision measures it and exports a print-ready STL, STEP and 3MF. This guide covers the full process step by step, and explains how the approach compares to free alternatives like Tracefinity.
In this article
- What is Gridfinity and why do custom inserts matter?
- What do you need to get started?
- How do you make a Gridfinity insert from a photo?
- How accurate is a photo-based Gridfinity insert?
- How does Snapfinity compare to free tools like Tracefinity?
- Frequently asked questions
What is Gridfinity and why do custom inserts matter?
Gridfinity is an open-source modular storage system built around a 42x42mm grid. You print baseplates that sit in drawers or on benches, then print bins that snap in and stack. The system is rearrangeable, expandable, and widely supported across the maker community with thousands of free models on Printables and MakerWorld.
The limitation is custom fit. Generic Gridfinity bins work well for screws, bits, and small parts, but the moment you want a tight-fitting insert for a specific caliper, router bit, or oddly shaped tool, you are looking at either modelling it yourself in CAD (which can take 30 minutes to an hour per bin) or accepting a rattling loose fit. Photo-based tools solve this by measuring the object from a photograph instead of from a set of calipers.
What do you need to get started?
The list is short: a phone or camera (any modern smartphone), a printer for the calibration board (plain A4 copy paper), a 3D printer (any FDM machine: Bambu, Prusa, and Creality all work), and Snapfinity itself, a one-time $9.99 download for Mac or Windows. No calipers. No CAD software. No cloud account required.
How do you make a Gridfinity insert from a photo?
Snapfinity uses four steps. Once you have the calibration board printed, each subsequent insert takes around 5 minutes.
Step 1: Print the calibration board
The calibration board comes included with Snapfinity. Print it once on a plain A4 sheet and reuse it for every object you measure. The board carries ArUco markers: machine-readable squares that give Snapfinity its real-world scale reference and let it correct for camera perspective automatically.
Step 2: Photograph your object
Place the object flat on the calibration board and photograph it from directly above. Even, diffuse lighting helps. You do not need a perfectly vertical angle: the ArUco markers handle perspective correction, so a slightly off-angle shot still produces an accurate measurement.
Step 3: Let computer vision measure it
Open Snapfinity and drag the photo to top photo box. The app detects the ArUco markers, corrects the perspective, and calculates the exact pocket dimensions: width, length and depth. No manual number entry. No calipers. Typical accuracy is within 0.5mm on each axis. Before exporting you can also add a scoop for easier tool pickup and a text label directly in the app. Magnets as well as a lip for stacking can be turned on or off.
Step 4: Export and send to your slicer
Click export. Snapfinity outputs three files at once: STL, STEP and 3MF. Drop the STL or 3MF into Bambu Studio, PrusaSlicer, OrcaSlicer or Cura. The STEP file is also fully editable in Fusion 360 or FreeCAD if you want to make further changes. First print fits.
Photo to print-ready Gridfinity insert in 5 minutes. No CAD. No calipers. Mac and Windows.
How accurate is a photo-based Gridfinity insert?
Snapfinity is accurate to within 0.5mm on each axis. That precision comes from the ArUco calibration board: because the app knows the exact physical size of the markers, it derives real-world dimensions from the photo without any manual input. Three things affect accuracy in practice: lighting (even, shadow-free light sharpens object edges), camera distance (the full calibration board needs to be in frame), and the object surface (hard, matte edges measure best; transparent or mirror-finish surfaces are harder but usually still workable). For most workshop tools, camera gear, household objects and maker parts, 0.5mm tolerance gives a snug, non-rattling fit on the first print.
How does Snapfinity compare to free tools like Tracefinity?
Tracefinity is a well-built open-source project that does a similar job. It is genuinely free and worth knowing about. The differences come down to measurement method and setup friction.
| Snapfinity | Tracefinity | |
|---|---|---|
| Price | $9.99 one-time | Free/trial (open source) |
| Setup | Download installer, run | Self-hosted via Docker or CLI, web-paid |
| Measurement method | ArUco markers, perspective correction, real dimensions | Silhouette trace from paper scale |
| Stated accuracy | Within 0.5mm | Not stated |
| Export formats | STL, STEP, 3MF | STL, 3MF |
| STEP (CAD editable) | Yes | No |
| Runs offline | Yes, fully local | Yes (after self-host setup) |
| Platform | Mac and Windows native app | Web UI (self-hosted) |
| In-app extras | Scoops, labels, magnet holes, bin editor, depth control, smoothness control and more | Magnet holes, bin editor |
| Multi-object | Yes | No |
The core measurement difference: Tracefinity traces the silhouette of a tool using a sheet of paper as a scale reference. That works for flat tools with clear outlines. Snapfinity uses ArUco marker detection to measure actual pocket dimensions with perspective correction, which is why it can quote a stated accuracy and a first-print-fits result.
The setup difference also matters for most makers. Tracefinity either requires paid subscription or running a local server via Docker or a CLI environment: straightforward for developers, a real barrier for most workshop users. Snapfinity is a standard desktop installer: download, run, done. If you want to have an insert printing in under 5 minutes from now, that difference is significant.
Frequently asked questions
Do I need CAD software to use Snapfinity?
No. Snapfinity generates the insert geometry automatically and exports it as STL and 3MF, which you send straight to your slicer. The STEP file is also included if you want to make edits in Fusion 360 or FreeCAD, but it is not required.
Does Snapfinity work with any 3D printer?
Yes. It outputs standard file formats compatible with all major FDM slicers: Bambu Studio, PrusaSlicer, OrcaSlicer and Cura.
What if my object has an irregular or curved profile?
Snapfinity measures the bounding dimensions and generates a rectangular pocket insert. It works best for objects with defined, hard edges. For highly irregular shapes, adding a few tenths of a millimeter of tolerance before exporting gives more clearance.
Can I edit the exported file?
Yes. The STEP export opens in Fusion 360, FreeCAD, or any CAD tool that accepts STEP files. The STL and 3MF are also editable in your slicer's built-in tools or in Meshmixer.
Does Snapfinity need a subscription or an internet connection after purchase?
No to both. It is a one-time $9.99 purchase. After the initial download, everything runs locally on your machine. No cloud, no subscription, no recurring fees.
Do my photos get sent to a server?
No. Everything runs locally. Your photos never leave your computer.
Can I create a multi-object bin?
Yes, put multiple objects on the calibration sheet and take the picture. The app will recognise seperate objects, create pockets and provide individual scoop for all objects.
What is Quick capture?
Quick capture is when you use 1 image (Top) only, here you define the depth and the bin is generated accordingly. If you turn of Quick capture, you have the option to upload side, front and back images as well. This will generate a highly accurate bin that seats the object perfectly. Note, this take a couple of minutes longer to compute all measurements.
Stop measuring by hand
One photo. Five minutes. A Gridfinity insert that fits on the first print.
Get Snapfinity for $9.99 →One-time purchase. Mac and Windows. No subscription.