Guides

Design parts that print the first time

Short, practical references. The same rules SpeakCAD applies when it writes your model.

23 September 2026

STL vs 3MF

STL and 3MF both work in every slicer, but they are not equal. Learn what each format stores, when 3MF is better, and which one to download from SpeakCAD.3 September 2026

Print-ready design rules

The design rules that make a 3D model print reliably on an FDM printer: wall thickness, overhangs, bridges, holes, chamfers, orientation. Applied automatically by SpeakCAD.3 September 2026

Tolerances & fits

How much clearance to leave for press fits, sliding fits, snap fits, lids and bearings on an FDM printer, and how to describe them so SpeakCAD gets the fit right first time.23 September 2026

Fit Check

Stop reprinting parts that are too tight or too loose: print a free 5-minute fit coupon, report the fit, and SpeakCAD calibrates every model to your printer.23 September 2026

Wall thickness

Minimum and recommended wall thickness for FDM and resin printing, how it interacts with nozzle size and perimeters, and what to ask SpeakCAD for on different parts.23 September 2026

Exporting to slicers

Step-by-step: download your model from SpeakCAD and print it with PrusaSlicer, Bambu Studio, OrcaSlicer or Cura. Units, orientation, multi-part files and recommended settings.29 September 2026

Slice an STL without installing

Turn an STL or 3MF into G-code for your printer in a browser, on a Chromebook, an iPad, a phone or a locked-down PC. Step by step, and what to check first.29 September 2026

Slicer settings for functional parts

Which slicer settings make a bracket, an enclosure or a clip work: orientation first, walls before infill, and what each setting costs in print time.29 September 2026

Print settings by material

What changes in the slicer for PLA, PETG, TPU, ABS/ASA and carbon-fiber blends: temperatures, speed, cooling, supports, adhesion and when you need an enclosure.3 September 2026

How to prompt for CAD

A practical guide to prompting an AI CAD tool: what to measure, how to describe features and fits, and how to iterate. Templates for brackets, enclosures, knobs and stands.23 September 2026

Phone to slicer

Where a downloaded STL or 3MF lands on iPhone and Android, and four reliable routes into PrusaSlicer, Bambu Studio, OrcaSlicer or Cura: app, shared folder, AirDrop, USB.23 September 2026

Check before download

A one-minute checklist for a generated model: assumptions, dimensions, mating faces, the bed, overhangs, walls and the ghost of the last edit. Spend credits on a file that prints.1 October 2026

Use it from ChatGPT or Claude

Add the SpeakCAD connector (MCP) to ChatGPT or Claude and sign in: SpeakCAD's own AI designs your part from the chat, shows it in 3D there, and gives the STL, 3MF or G-code, on your account's credits.30 September 2026

SpeakCAD in ChatGPT

Add SpeakCAD to ChatGPT and sign in: ChatGPT hands your part to SpeakCAD's CAD AI, shows it in 3D in the chat, and gets you the STL, 3MF or G-code.1 October 2026

SpeakCAD in Claude

Connect SpeakCAD to Claude: Claude hands your part to SpeakCAD's CAD AI, shows it in 3D in the conversation, and gets you the STL, 3MF or G-code.30 September 2026

Slice from ChatGPT or Claude

Add the SpeakCAD Slicer connector to ChatGPT or Claude: name your printer and settings in the chat, get a link that opens the online slicer with them selected, drop your STL or 3MF and download G-code (380+ printers).17 October 2026

Hand tools

Nine hand tools for people who print: tap a face of a part, add a hole sized for a screw (with a countersink or a counterbore) and type how far it sits from the edges, cut a pocket or a nut trap, add a tab, write raised or engraved text, pull a flat face out or push it in, round or chamfer the corners or the edges of a face, hollow the part or measure, and duplicate a hole into a row, a grid or a circle, with the numbers in millimetres. Free, on your phone, no account needed to try.17 October 2026

Round corners and edges

How to round or chamfer the corners of a part in SpeakCAD with the Round tool, and the edges around a flat face with the Fillet tool, why a rounded edge prints better, fillet versus chamfer on an FDM printer, and when an edge is a request for the AI.5 October 2026

Add a hole to an STL

Put a screw hole in an STL you downloaded, right where you tap, with the diameter in millimetres: the Hole tool in SpeakCAD, on your phone. How to upload the file, where the AI steps in to resize an existing hole, and what each step costs.5 October 2026

A hole at an exact distance

Place a screw hole with its centre an exact number of millimetres from a part's edges: tap Hole, tap the face, pick M3 or M4, type the two distances, Apply. On a phone or a computer, free; measured at 4 taps and 2 typed numbers.5 October 2026

Move a hole or a cut

A hole, a cut or an added tab stays editable after Apply in SpeakCAD: retype its distances from the face's edges, tap Move and then the new spot, or drag its handle. Moving a hole 10 mm is 1 tap and 1 typed number, measured.5 October 2026

Rotate a slot or a rectangle

A rectangle or a slot you cut into a face or add onto it turns with its Angle in SpeakCAD: quick 15°, 30°, 45° and 90° chips, or any angle typed, before Apply or later on its card. Free, on a phone or a computer.5 October 2026

Extrude a face

Make a plate thicker, a wall taller or a pocket deeper by moving one flat face: tap Extrude, tap the face, Pull out or Push in, type the distance, Apply. 3 taps for 5 mm, measured; free, on a phone too.5 October 2026

Duplicate a hole

Turn one hole into a row of screw holes, four holes in the corners of a plate or a bolt circle: tap it, Duplicate, pick Line, Grid, Circle or Mirror, type the copies and the spacing, Apply. Up to 100 copies that stay numbers you can change. Free, on a phone too.5 October 2026

Countersink or counterbore

Sink a screw head flush in a printed part: tap Hole, pick the screw size, choose Counterbore for a socket head or Countersink for a flat head, Apply. M3 is a 3.4 mm hole with a 6.5 × 3.4 mm counterbore or a 6.6 mm countersink; the M2 to M8 table and how each prints.5 October 2026

Raised or engraved text

Put a label, a name or a part number on a flat face of a part or of your own STL: tap Text, tap the face, type up to 40 characters, choose Raised or Engraved, set the Letter height and Depth, Apply. The sizes that print legibly, and the honest limits.5 October 2026

From Tinkercad

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.7 October 2026

Order a print

Step by step: get the part you designed, or a library model, printed in PLA or PETG and delivered. Price from a real slice, from $1.19 + shipping, 1 to 100 copies.

Your next print is a few taps or one sentence away

Shape a part with the free hand tools on your phone or computer, or describe it and let the AI build it, then download an STL, or G-code sliced for your printer. A free account brings the hand tools and their files, plus your first AI part on us (some accounts confirm it with a card first, nothing charged that day); then the AI runs on credits, from Maker at $7.99 a month for 50 credits, or Pro from $14.99 a month, cancel anytime. Nothing to install. Not sure yet? Shape a real part in the live demo first, no account needed.

Get startedSee pricing