Support

Write to support@lets3dprint.app. Include your macOS version and, if you can, the project file.

Request a feature

Missing a tool, or something works differently than you expect? Fill in the feature request form and tell us what you want to print. In the app it is under Help → Request a Feature… and in Lets3dPrint → Settings.

Requirements

macOS 26 or later on a Mac with Apple silicon.

Getting started

1. File → New.
2. Click Create Sketch (or press S), pick the XY plane, click OK.
3. Pick the rectangle tool, click two corners. Type a width and height in the boxes next to the cursor if you want exact sizes.
4. Click Extrude (or press E), drag the blue arrow or type a distance, click OK.
5. Select edges and click Fillet (F) to round them.
6. Export → STEP or STL, and open the file in your slicer.

Navigating the view

• Orbit: drag with the mouse, or scroll with two fingers on the trackpad
• Pan: right-drag, or Shift + two-finger scroll
• Zoom: pinch, or the mouse wheel
• View cube (top right of the view): click a face, edge or corner to turn the view, or drag it to orbit
• Under the cube: Home view, Fit All, and perspective or orthographic

Common questions

Extrude does nothing. Extrude starts at 0 mm. Drag the arrow or type a distance, then click OK.

My sketch has no profile to extrude. Profiles are closed areas. Make sure lines meet at their ends; the closed areas are tinted orange.

A fillet fails. The radius is too large for the edge or its neighbours. Try a smaller value; the reason shows in red and OK stays disabled until the preview builds.

Revolve: picking the axis. Pick a profile or a flat face of a body, then click the axis: a line of any sketch (also one drawn on its own offset plane), a straight edge or the X, Y or Z axis. The axis may run along the profile's edge or beside it, but not through it. Click a picked profile or axis again to unpick it; ✕ next to a field clears it.

Hiding sketches. Click the eye next to a sketch in the sidebar, or Hide All / Show All next to “Sketches”. A sketch used by an extrude hides itself until you show it.

Holes. Click Hole (H), click a flat face where the first hole goes, then click more places. Click a hole again to remove it. Choose Simple, Counterbore or Countersink in the dialog.

Text and logos. In a sketch, pick the Text tool and click; type the text in the inspector. Text on Path follows a curve you click. For a logo, use Modify → Insert SVG… and set its width. Select the text or logo, then Create → Emboss to raise it or sink it into the face, or Extrude it.

Patterns. Modify → Rectangular or Circular Pattern repeats bodies; in a sketch the Modify menu repeats curves. Drag the arrow for the spacing and type the counts in the boxes.

Sweep, Pipe and Rib. These follow sketch curves: click the curves of the path (joined end to end). Sweep first asks for the profile, then the path.

Enclosures. Modify → Shell, click the faces to leave open, type the wall. Walls grow inwards.

Threads. Modify → Thread and click the side of a rod or the wall of a hole; the fitting metric size is picked. Raise the clearance if printed parts are too tight.

Measuring and weight. Inspect → Measure (I). Click two places for a distance; the dialog also shows the size, volume and solid weight of the body in the material you pick. Slicers print with infill, so real parts weigh less.

Print Check. Click Print Check in the toolbar, or Inspect → Print Check (⌥⌘P). Pick your nozzle and type the layer height; walls too thin to print and gaps that close up are marked red on the model, thin walls and tight gaps in orange. Click Show next to a place to turn the view to it. The check runs again after every change. Print Check is part of Pro.

Overhangs and section. Inspect → Show Overhangs paints faces leaning out past your angle red. Section View cuts the view along a plane; set the plane and position at the bottom left.

3MF, STEP and meshes. Export → 3MF keeps each body as its own object. Create → STEP / STL (or File → Import STEP, STL or 3MF…, ⌥⌘I) opens STEP models with each part as a body, and STL and 3MF files as solid bodies (the mesh must be closed).

Parts library. Create → Library (⇧⌘L). Pick a part, set its values with the sliders and choices, press OK: it is added as ordinary steps. Make Smart Object keeps it to place many times. With a script open, Code → Save to Library adds it under My Parts. Free.

Textures. Generate → Texture, click the faces (click again to unpick), choose a pattern and set the depth (negative presses it in) and the repeat. Near the edges of the textured faces it fades out over “Fade at edges”. If the panel says a detail is finer than your nozzle, make the repeat bigger. Textures are in STL, 3MF and Print Check; STEP keeps the exact shape. The preview is free; keeping it needs Pro.

Surface waves. Generate → Waves, then click where drops fall; click a drop again to remove it. Height, wavelength, fade and phase are in the panel. “Only the faces clicked” keeps the sides flat. The preview is free; keeping it needs Pro.

Smart objects and copies. Make one from a Library part (Make Smart Object) or from an open script (Code → Make Smart Object). Arrange → Copies places it: at points you click, in a grid on a plane, or over faces at a spacing. Under Values, set them for these copies, or click Value from Position and write a formula with x, y, z, d (distance from the middle), i (number) or n (count). Double-click an object in the sidebar to change it; every copy follows.

Data to 3D. Generate → Data and choose a CSV, TSV or text table. Choose Bars, Surface or Columns at x, y; set the cell size, the tallest bar and the base. Click Stand on, then a plane or a flat face, to place it there.

Flow lines. Generate → Flow Lines shows a lampshade at once; choose another preset (Twisted Vase, Wavy Lines, Braid) or change it. r is the radius in mm as a formula of the height (t goes from 0 at the bottom to 1 at the top); Turn says how far each line has turned round the axis, in degrees, where p is the angle between two lines and i the line's number. Both ways adds a mirrored twin to every line so they cross. Drag the height arrow, type the number of lines on the model, set the line width, thickness and rims. Pick a flat face first and the lines stand on it, joined to that body. Free.

Twist locks. Arrange → Twist Lock, click the body, then a plane through it. The part behind the plane gets a boss with lugs, the part in front a socket; push them together and turn the front part clockwise. Set lugs, turn, size and clearance in the panel. The cut face needs some room: the lock fits itself inside it, or says it is too small.

Printing helpers. Holes into a side face: choose Top → Teardrop in the Hole panel (or Modify → Teardrop). Counterbores opening on the bottom get a bridge layer to drill out after printing. Modify → Bed Chamfer chamfers every edge on the bed; Modify → Brim Ears adds discs to sharp corners. Arrange → Lay on Face turns a body onto the face you click; Arrange → Arrange spreads all bodies on your printer's bed (choose the printer in the Analyse tab, where Bed shows its outline).

Finding a tool. Press ⌘K and type part of its name or what you want, such as “hollow” or “screw”.

Scripts. Code → Script (⌥⌘S): the timeline appears as plain lines beside the model, and the Code tab shows what you can do with it. Change a value and press Run (⌘↩); the part rebuilds, and ⌘Z undoes it. You can also write steps yourself, with names, sums and repeat loops. Numbers set at the top of a script show as fields and sliders above it. Code → Save Script keeps it as a file, From Timeline writes it again from the steps, Reference lists every command; File → Run Script File… (⇧⌘R) runs one in any project, adding its steps to the timeline. Every command is in the script reference. Reading the script is free; running it needs Pro.

Restore Pro on another Mac. Lets3dPrint → Settings → Pro → Restore Purchases, signed in with the same Apple Account.

Cancel a subscription. App Store → your name → Account Settings → Subscriptions.