CAD for people who own a 3D printer
A print-in-place planetary gear bearing, herringbone teeth, 4 planets, module 1.5, with a hex drive in the sun.→ Planetary gear bearing
Loftsmith is CAD you can talk to. Describe the part, add one measurement, and it's designed around your printer and your filament. Every clearance, overhang and wall is checked, and you get a file already laid out on your bed.
A print-in-place planetary gear bearing, herringbone teeth, 4 planets, module 1.5, with a hex drive in the sun.
01 — The almost-fits tax
You find an STL that's close enough. You print it. Three hours later the lid won't close, the hole is two millimetres off, or the clip snaps the first time you use it.
So you open CAD. You watch half a tutorial. You close CAD.
Every round costs filament, an evening, and a little of the fun. (Call it the almost-fits tax. Every maker pays it.)
Loftsmith cuts out the guessing in the middle. Your part is designed around your measurements, your printer and your material, and checked, before the first layer goes down.
02 — How it works
Type it the way you'd tell a friend. Add a photo and drag a line across something you've measured. The ends snap to the real edges.
Why the measurement? Because a photo can't tell 60 mm from 66 mm. You can, in five seconds with a ruler.
The part is written as real, parametric CAD and built in front of you. Drag a slider and it rebuilds instantly. Circle any spot and say what to change. No more describing “the bit near the top left”.
Why are sliders free? Because they run on your computer, not our servers. They cost us nothing, so they cost you nothing.
Not sure about a snap-fit or a screw boss? Circle it and print just that section, 8.5 g instead of 65 g. When it fits, download the whole thing, already split into plates for your bed.
Why would we tell you to print less? Because a part that fits first time is the only thing that brings you back.
03 — Before your printer sees it
Every version is sliced into layers, scanned for overhangs, measured against your bed and checked for walls too thin to print. You see what it found and what it changed. No black box.
04 — Proof you can open
Every model below is live: real CAD, real checks, adjustable in your browser. The numbers come from the actual build. The 12 g wall hook, for example, checks the inside of its bend with curved-beam math: 14.9 MPa inside the bend at 5 kg hung suddenly (curved beam x1.28); PLA allows 16.7 along the layers.
MechanicalGenerate a print-in-place planetary gear bearing: herringbone sun, four planets and a ring printed assembled.
MechanicalA camera-style lens barrel that zooms when you twist it: a hidden helical cam, click-together ring and snap cap.
MechanicalGenerate print-in-place chainmail: interlocked links printed flat as one sheet that drapes like fabric.
WorkshopGenerate a box that prints open with its hinge already assembled, then folds shut onto its rim.
Home & deskGenerate a sculpted headphone stand: one smooth body with a cradle cut to your headband's arc.
RC & FPVA 1 m PLA pusher flying wing Loftsmith designed from one prompt: 18 parts, carbon spar, magnetic battery hatch, 68 engineering checks passed.
On the benchWhat these look like off the plate and in use. Illustrations made with AI from the models above.
Planter in matte sage PLA2 parts · no supports
Storage box with removable pin3 parts · no supports
Cable clips fresh off the platePLA · no supports
Phone stand in matte black PLA1 part · no supports
Wall hook in galaxy-grey PLA1 part · no supports
Open enclosure in galaxy-grey PLA2 parts · no supports
Hex bit holder in orange PLA1 part · no supports
Blue caddy with draining floor1 part · no supports
One-piece shelf in off-white PLA1 part · no supports
Headphone stand in matte-blue PLA1 part · no supports
Printed planetary gear bearing6 parts · no supports
Interlocked printed links41 parts · no supports
Hinged box in charcoal-grey PLA2 parts · no supports
15 PARTS · LW-PLA · CARBON SPAR05 — Built for a harder problem first
The Fabled Wing is a 1-metre FPV plane in 15 printable parts: swept panels braced by a modelled internal lattice, a bore for the carbon spar, alignment pins at every joint and elevons on the outer panels. Change the span and every panel is re-sized for your bed, and wing loading and stall speed are re-checked.
If it can keep a wing honest, your drill mount is in safe hands.
Design checks, not flight tests. Balance it and trim it like any wing before the first launch.
Open the wing06 — What it's not for
Better you hear it now than after your first credit.
07 — Pricing
A 1 kg roll of PLA costs around $20. For $19.99 a month you can design about 10 new parts of your own, each checked for your printer before it ever sees filament. Sliders, checks and downloads are free forever, because they run on your computer.
Design your first parts and use every generator.
$0free
Free account · nothing charged
For makers who print every week.
$19.99USD / month
about 67¢ a day
Billed monthly · cancel anytime
Multi-part products and client work.
$39.99USD / month
Billed monthly · cancel anytime
08 — Questions
Credits pay for design work: the AI reading your design and working out the change. What a design costs depends mostly on how many rounds it takes, not on how complicated the part is. One request for one part usually takes 3–7 credits. A part you refine over a few rounds takes 5–12. A long project with many rounds takes 15–30 or more, because every change starts by re-reading the whole design so far. So several changes in one message cost less than sending them one at a time. Before you send a message the Studio shows what it usually costs, you get a receipt after, and you can stop any time; if one message runs well past its usual cost, it pauses and asks before going on. Moving sliders and re-exporting is always free because it runs in your browser.
Text-to-3D generators sculpt a mesh that looks right. Loftsmith builds a part that measures right: it writes parametric CAD, uses real hardware dimensions (screws, inserts, bearings, boards), checks bed fit, overhangs and thin walls for your printer, and runs engineering checks like bending stress or tip-over before you print.
Any FDM printer. Pick a profile (Bambu Lab, Prusa, Creality, Voron…) or a generic bed size; parts are checked against its build volume and split with alignment pins when they don't fit.
You do. Paid plans include commercial use of everything you design and print, so you can sell the products you make.
STL per part and 3MF with every part laid out on a plate. Your design stays in your projects, so you can reopen it and change it any time. STEP export is in beta on Pro.
Firearms, firearm parts and weapon accessories. Everything functional and legal — tools, mounts, enclosures, RC and drone parts, jigs and fixtures — is fair game.
Create a free account. Google or email, no card needed. Your first design is free.
Type the part you need. One sentence is enough. Add a size if you know it.
In about a minute you have a model, checked for your printer. Not right? Circle what's wrong and say so.
P.S. Not ready to describe anything yet? Open the print-in-place hinged box and drag the sliders. It's free, it runs in your browser, and within ten seconds you'll see the hinge gaps (0.35 mm radial and 0.4 mm axial gaps around every knuckle) being re-checked as you go.
