--- title: "From Tinkercad to SpeakCAD: dimensions that stay linked" description: "What changes when you move from Tinkercad to SpeakCAD: the same tap-and-size simplicity, on a phone, with every size kept as a number you can retype, rounded corners, holes sized for screws, and an AI for the parts Tinkercad cannot shape." canonical: https://speakcad.com/guides/tinkercad-to-speakcad published: 2026-10-04 updated: 2026-10-05 publisher: SpeakCAD --- # From Tinkercad to SpeakCAD: dimensions that stay linked > What changes when you move from Tinkercad to SpeakCAD: the same tap-and-size simplicity, on a phone, with every size kept as a number you can retype, rounded corners, holes sized for screws, and an AI for the parts Tinkercad cannot shape. Tinkercad taught a generation of printer owners that CAD can be dragging boxes together. It also stops at the same three places for everyone: no phone, no rounded edges, and a revision means dragging everything again. SpeakCAD keeps the simplicity and fixes those three. Here is what maps to what. ## Steps 1. **Start from a shape, not an empty workplane.** Pick Open box, Plate, Cylinder or Tray on the new model screen. Tap the part and type its sizes: 80, 50, 4. There is no shape to drag to size by eye. 2. **Holes are a tool, not a hole-shaped box.** Tap Hole, tap the face, pick M3 or M4, Through, Apply. In Tinkercad a hole is a second shape set to Hole and grouped; here it is a feature with a diameter you can retype. 3. **Round the corners with a slider.** Tap Round, tap the top face, set a radius. Tinkercad has no fillet; the usual workaround is stacking cylinders at the corners. 4. **Revise by retyping.** Tap the part or a feature and change its number; the part rebuilds with its rounded corners intact. Nothing is regrouped, nothing is realigned. 5. **Describe what the tools cannot shape.** Type the rest to the AI, one change per message: a lid that fits, a wall 2 mm thicker everywhere, a mirrored copy. Each request spends 2 credits; the hand edits stay. ## What Tinkercad got right Tinkercad is easy because every action is visible: a box, a cylinder, a hole, drag, align, group. There is no sketch, no constraint, no feature tree. For a first print, that is the right amount of CAD, and it is why every "best free CAD for 3D printing" list of 2026 still puts it first for beginners. SpeakCAD keeps the same idea, one visible action at a time, and puts it on the device you already hold while you stand at the printer. ## The three walls people hit **No phone.** Tinkercad needs a browser window at least 864 pixels wide; phones are unsupported. SpeakCAD is a phone editor first: the tools sit above the chat, the cards open from the bottom, the model recompiles in your browser. **No rounded edges.** Tinkercad has no fillet. The forum workaround is to place cylinders at each corner of a box and union them, then redo it when the box changes size. In SpeakCAD, **Round** is a tool: tap the top face, set a radius, and the corners of the part's outline are rounded. Resize the part and the radius stays. For a single edge or the top edges of a box, the AI does it from one sentence. **Revisions mean dragging again.** Tinkercad shapes have size fields, but they are not linked: change the plate and the hole-shaped boxes have to be moved and the group redone. In SpeakCAD a part is a program under the hood. The sizes of the starters and of AI designs are named numbers: tap one, type a new value, and the part rebuilds with its rounded corners intact. A hole you added is a feature too: its diameter and depth are numbers on its card, and so is where it sits, its centre's distance from the face's edges, so it stays exactly where you placed it. If you make the part longer afterwards, check the hole with Measure and, if it should have moved, change its Position on its card; that is one number, not a regrouping. ## What maps to what | In Tinkercad | In SpeakCAD | |---|---| | Drag a box onto the workplane, size it by handles | Start from a shape (Open box, Plate, Cylinder, Tray), tap it and type the sizes | | A second box set to "Hole", aligned, grouped | Hole tool: tap the face, choose M2 to M8 or type a diameter, Through, Apply | | A hole-shaped box for a slot or recess | Cut tool: Rectangle, Circle or Slot, with Width, Length, Corner radius, Depth | | A box or cylinder unioned onto the part | Add tool: a tab, boss or peg standing on the tapped face, with its Height | | A box stacked on top to make the part thicker | Extrude tool: tap a flat face, Pull out or Push in, type the Distance | | Cylinders at the corners for a rounded look | Round tool: a radius on the corners of the face's outline | | Ruler tool to set a shape's position | Position rows on a hole, a cut or a tab: Centre 12 mm from the left edge, typed | | Ruler tool to check a distance | Measure: two taps for a distance, plus the face size and wall thickness | | Rebuild by hand for anything organic or complex | Describe it to the AI, one change per message | | Export STL | Download STL, 3MF, or G-code sliced for your printer | ## What each one costs Tinkercad is free. In SpeakCAD, the hand tools are free too: Shaping a part by hand (a hole, a cut, an added tab, an extruded face, rounded corners) and downloading what you shaped are free. Each AI request spends 2 credits, a download of AI work 4 credits, and G-code 5 more. The AI is the paid part, because every request runs a model on a server for you. The live demo runs the hand tools without an account; a download needs a free one, and the credits you have are shown in the editor. ## A first part, both ways A battery holder lid, 60 by 35 mm, 2 mm thick, with two M3 screw holes 50 mm apart and soft corners. In Tinkercad: drag a box, type 60, 35, 2 in its fields; drag two cylinders, set them to Hole, type 3.4 for their diameter, align them with the ruler so their centres are 50 mm apart, group. For the soft corners, four more cylinders at the corners, unioned, and a box subtracted to trim them, or skip it. Export the STL on a computer. In SpeakCAD, on your phone: Start from a shape, Plate. Tap it, type 60, 35, 2. Tap **Round**, tap the top face, radius 3, **Apply round corners**. Tap **Hole**, tap the top face near one short end, **M3**, **Through**, set Position to **Centre 5 mm from the left edge** and **Centre** on the other row, **Apply hole**. Same at the other end, 5 mm from the right edge: the holes are 50 mm apart. Tap **Measure** and tap both hole centres if you want to see it. Download the STL, or the G-code for your printer. Nothing in that list spent a credit. ## Bringing your Tinkercad models along Your Tinkercad designs export as STL. Hand the file over with nothing typed (the **Upload an STL or 3MF** card in a new model's empty editor, the [Edit an STL](/edit-stl) box or the [online slicer](/slicer)'s Change it with AI with the change left empty, or SpeakCAD's card in ChatGPT or Claude with no change) and it opens as a model at once, with no AI turn. From there, **Hole**, **Cut**, **Add** and **Extrude** (on a flat face) work on it by hand, free to apply, and **Measure** reads it; a part started from your file and shaped by hand downloads free, like one started from a shape. On your own STL or 3MF opened with no AI turn, the whole file is one part, so Round rounds the corners of its outline seen from the face you tapped: right for a boxy part, and refused when the radius would take off more than the corners. For linked dimensions and a single rounded edge, "rebuild this as a parametric model with the same size" is an AI request, 2 credits: every dimension becomes a number you can type. Once the AI has worked on the model, its download spends 4 credits, with small fixes re-downloading free. ## Where SpeakCAD asks you to type instead Anything you would do in Tinkercad with twenty shapes and an hour: a snap-fit lid, an enclosure with port cutouts for a specific board, a replacement knob with a D-shaft, text on a face. In SpeakCAD that is a sentence with the measurements, 2 credits per request, and the result keeps every hand edit you made before. The [prompting guide](/guides/prompting-for-cad) shows what to include. The [Tinkercad comparison page](/vs/tinkercad) has the side-by-side facts. ## About SpeakCAD SpeakCAD is the easiest way to design a part with real dimensions on your phone: shape it with simple tools or describe it to the AI, and download a print-ready STL, 3MF or G-code sliced for your printer. SpeakCAD works inside ChatGPT and Claude as a plugin (an MCP server): ask the assistant for a part with its measurements and SpeakCAD's own CAD AI designs it, shows it in 3D in the chat and hands over a print-ready STL, 3MF or G-code sliced for your printer. - Live demo, no account: https://speakcad.com/demo - In ChatGPT, Claude and other MCP clients: https://speakcad.com/chatgpt-plugin, https://speakcad.com/claude-connector, https://speakcad.com/mcp-server - Pricing: https://speakcad.com/pricing - FAQ: https://speakcad.com/faq - Site index for AI assistants: https://speakcad.com/llms.txt