Shape a part by hand in SpeakCAD: hole, cut, add, extrude, round, measure

Who the hand tools are for

You own a printer. You can download and slice a model, and you have probably opened a CAD program once and closed it again. The parts you need are small and plain: a plate with four screw holes, a box with a cable slot, a tray that fits a drawer, a peg that holds a shelf. The hand tools are for exactly that, and nothing more.

There are six of them, and each does one thing you can say in a sentence. They live in a rail above the chat: Hole · Cut · Add · Extrude · Round · Measure. On a phone the rail sits just above the chat peek bar, and the card for a tool opens as a sheet from the bottom, so your thumb never leaves the lower half of the screen. On a computer the rail is in the toolbar and the keys H, C, A, E, R and M switch tools.

Starting without the AI

A model has to start somewhere. A new model opens on an empty editor that reads "Start from a shape, or describe it in the chat", with four starters as large cards: Open box (floor and four walls, rounded corners), Plate (a flat plate with rounded corners), Cylinder (a solid cylinder standing on its end) and Tray (a shallow tray with a lip around the rim). The models screen has the same four under Start from a shape. Each opens with its sizes as named numbers: tap the part, type 80 for the width, and it is 80 mm wide. No AI call is made, so no credits are spent.

Your own STL or 3MF starts a model the same way: the Upload an STL or 3MF card next to the starters, or any other way of handing it over with nothing typed (the Edit an STL box or the online 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. The hand tools work on the mesh as it is, and a part shaped by hand on your file downloads free, like one started from a shape.

The first line in the chat tells you what to do next: "Started from a box. Tap a face to add a hole, cut, or round its corners, or describe a change to the AI." Both doors stay open.

Hole

Tap Hole, then tap the face where the hole goes. The card shows Diameter and Depth. The presets are the clearance sizes for metric screws: M2 (2.4 mm), M2.5 (2.9), M3 (3.4), M4 (4.5), M5 (5.5), M6 (6.6), M8 (9.0). A small tap toggle switches them to the smaller sizes a screw cuts its own thread into. For the depth, Through goes all the way through the wall under your finger, plus a millimetre so no skin is left. Press Apply hole.

The hole is drilled along the direction you are looking at the face from, where you tapped, and the Position rows under the sizes put its centre exactly where you want it (see below). Printed holes come out a little small, which is why the clearance presets are already a bit larger than the screw.

Cut

Cut takes a pocket out of the tapped face. Pick the Shape (Rectangle, Circle or Slot), set Width and Length (or Diameter for a circle), a Corner radius for the rectangle, and the Depth, with Through for a window. A cable slot through the side of a box is a Slot, 12 mm long and 4 mm wide, Through. A recess for a rubber foot is a Circle, 8 mm, 1 mm deep.

Add

Add stands a new piece on the tapped face: a boss, a tab or a peg. Same shapes as Cut, plus a Height (5 mm by default). A tab to screw the part to a wall is a Rectangle, 20 by 10, 3 mm high, standing on the back face, with a Hole through it next. A peg that locates a lid is a Circle, 4 mm, 3 mm high.

Add stands a new shape on the face. To make the face itself thicker or thinner, use Extrude.

Put it exactly where you want it

Your tap picks the face and a first spot. The exact spot is a number. Under the sizes of a hole, a cut or an added tab, the Position group has two rows, one for each direction across the face, and each reads like a sentence: Centre 12 mm from the left edge. Type the distance, or use the ± steppers. The edge select switches a row to the opposite edge (left or right, front or back, top or bottom, named after the way each edge faces), so you measure from whichever edge your drawing or your calipers start from. The Centre chip on a row centres it in that direction, and Centre on the face centres both. The marker on the model moves as you type.

The distances run from the edges of the flat face you tapped to the centre of the hole, the cut or the tab. On a slanted face the rows say "one edge" and "the opposite edge", since left and right no longer mean much there. When the shape would reach past an edge, the card says so ("Closer than its radius to the left edge: it will cut through the edge") and still lets you apply it, because a notch through the edge is sometimes the point.

A plate 80 by 50 mm with an M4 hole 6 mm in from each corner: tap Hole, tap the top face near a corner, M4, Through, then Centre 6 mm from the left edge and 6 mm from the front edge, Apply hole. The next one is 6 mm from the right edge and 6 mm from the front edge, and so on round the plate. The holes end up 68 by 38 mm apart, centre to centre.

Placing is not final at Apply. Tap the feature later and its card shows the same two rows above its sizes; change one and, after a short pause, the part rebuilds as a new version, with a line in the chat such as "Moved Hole 1: centre 12 mm from the left edge, 8 mm from the front edge." A feature added before 5 October was not placed this way, so its card does not give its distances from the edges.

Extrude a face

Extrude moves the face itself instead of adding a shape on it. Tap Extrude, then tap a flat face. The card shows the face's size ("Face 60 × 40 mm"), a choice between Pull out and Push in, and the Distance (5 mm out or 1 mm in to start). Press Apply and the whole face moves that far along the way it faces, with its outline as it is: rounded corners stay rounded, and a hole through the face stays open when you pull it out.

Pull out the top of a plate to make it thicker, the rim of an open box to make its walls taller, or the end of a peg to make it longer. Push in the floor of a pocket to make it deeper, or the top of a tab to make it shorter. On its card afterwards the Distance is one signed number: positive pulls out, negative pushes in, and typing the other sign turns one into the other.

Extrude takes a whole flat face, never part of one, and it has no Position rows: nothing is placed, the face moves where it is. A curved face is refused ("Extrude works on a flat face: tap a flat one, or ask the AI"), with a chip that writes the request for the AI into the chat. A face whose outline is very detailed, as on some downloaded meshes, can be too much to extrude by hand, and the card says so; that one is an AI request too.

Round

Round softens the corners of the part you tapped. Set the Radius with the slider or type it, and press Apply round corners. It rounds the corners of the tapped face's outline, that is, the edges that run parallel to the direction you are looking from. On a box tapped from above, that is the four vertical corners. On a plate tapped from above, the same. The slider stops at half the smallest size of the part, so the result stays a solid.

What Round does not do: a single edge, or the top edges of a box. The card says so, with a button, Ask the AI to round just this edge, that writes the request into the chat for you. Sending it is an AI request (2 credits). There is more on this in Round the corners of a 3D-printed part.

Round also needs a part with a name. The starters have them, and a model the AI designed has them. 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. Only when the AI has written the program around a file you attached in the chat without naming it does the card ask you to have the AI label the parts first.

Measure

Measure changes nothing. Tap once for point A, again for point B, and the overlay shows the distance in millimetres with its ΔX, ΔY and ΔZ, plus the size of the last face you tapped and the wall thickness behind it. Tap a third time, or Clear, to start over. It is how you check a hole spacing before you print, or find out how thick a wall is before you cut into it.

The card shows the numbers

After Apply, the new feature is selected and its card shows only its own numbers: the hole's diameter and depth, the cut's width and length, the extrude's Distance, and for a hole, a cut or a tab its two Position rows. Change a number there and the part recompiles. The feature stays a feature: it is not baked into triangles, so a 4.5 mm hole can become 5.5 mm next week. Every Apply is a numbered version, with undo and a ghost of what changed, and a feature you no longer want has a Remove button on its card.

When to type to the AI instead

The hand tools cover a face at a time. For anything that is not "this feature on this face", the chat is one tap away: hollow the part, add a lid that fits, move the whole cutout pattern, round the top edges, rebuild it from a photo. The AI reads your hand edits as part of the model and keeps them. Each request spends 2 credits (up to 10 on a very large model), and a download of a model that contains AI work spends 4 credits, with small fixes re-downloading free.

What it costs

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. On the live demo the tools work without an account; downloading needs a free one. G-code sliced for your printer is included in Pro and Unlimited.