2. The canvas#

Chapter 1 drew two circles by typing a radius and clicking. That is the easy case. This chapter is about the rest: getting around a drawing, selecting exactly what you mean, moving and sizing things precisely, drawing freehand, and reshaping a path point by point.

Everything here happens in the 2D View, and nothing here cuts anything — this is the drawing half of the app. Cutting is chapter 4 onward.

Getting around#

The grid spacing is shown bottom-right, and the status bar along the bottom always reports the current mode, the stock, and the machine rigidity — so if a click isn't doing what you expect, look there first. Mode: Select means clicks select; Mode: Circle means the next click places a circle.

The mm / in toggle changes only what you see and type. Millimetres are what the project actually stores, so switching units never moves anything, never introduces rounding, and a file saved by someone working in inches opens correctly for someone working in mm.

Selecting#

Clicking is the obvious half. The part worth learning is the drag box, because it asks one of two genuinely different questions and the direction you drag chooses which.

The two box directions matter on a crowded drawing. Everything this box runs across picks a row of parts out of a nest. These, and nothing they overlap picks one wheel out from under the arbor crossing it. The outline tells you which you're about to get, and it is the only thing on screen saying so:

Dragged right → dashed box, takes what it touches	Dragged left ← solid box, takes only what's wholly inside
Catches the polygon and the heart — the box crosses it	Catches the star only

The test is on each object's bounding box, not its outline — so an L-shaped path counts as touched by a box sitting in the crook of its own bounding box.

An enclosing box treats a group as one object: a group half inside the box is not selected at all, rather than coming back as the handful of its parts that happened to fall inside.

The Paths list#

The sidebar's Paths tab lists everything in the project by name, which is the reliable way to grab something small, something buried under something else, or one path inside a group.

Selecting a path in the list selects it on the canvas, and its properties appear underneath.

The Properties panel#

Select something and the Properties panel appears under the paths list, in two sections that answer two different questions:

• Shape — what this thing is. A circle's radius, a gear's module and tooth count, a star's point count. These are the parameters the object was generated from, and editing one regenerates the object.
• Transform — where it is and how big. Centre, width and height, rotation angle. These are absolute: type 75 into CX and the object's centre goes to X 75, it doesn't move by 75.

A path that came from an SVG or the pen tool has no Shape section — there are no parameters to recover, only geometry — so it shows Transform alone.

Below them:

• Mirror X / Mirror Y flip the selection about its own centre.
• Resize from centre decides whether dragging a corner handle grows the object outward from its middle or from the opposite corner. It rides with the object, so you can change your mind later.

Moving, scaling and rotating#

Select something and handles appear around it.

For anything that needs to be exact, type it into the Transform fields rather than dragging. Dragging is for arranging; the fields are for dimensions.

Rotating or non-uniformly scaling a generated shape gives up its parameters. A circle stretched into an oval can no longer be described by a radius, so its Shape section goes away and it becomes an ordinary path. Moving it, or scaling it evenly, keeps the parameters intact. If you want an ellipse, draw an ellipse.

Gear, Escapement, Pendulum and Track refuse drag-scaling entirely — they don't even draw resize handles. Their size comes from module and tooth count, from the beat, or from the piece they must connect to. Change those numbers in the Shape section instead.

Groups#

Select several paths and press Ctrl+G (or Group in the Properties panel) to tie them together. After that, clicking any member selects the whole group, and they move, scale, rotate and delete as one thing. The Objects strip shows them as a single chip.

• Ctrl+Shift+G ungroups.
• Alt-click reaches a single path inside a group without ungrouping.
• Groups nest. Group a group with a shape, and ungrouping once gives you back that group and that shape — one level at a time, not a pile of loose paths.

Constraints#

A group ties parts together rigidly. A constraint does something different: it holds one part a stated distance from another, and keeps it there as either one is edited. Four holes 10 mm in from the corners of a mounting plate stay 10 mm in from the corners when the plate is resized — or turned.

Making one#

1. Press C, or Constrain in the Constraints section of the Properties panel.
2. Move over a part and its attachment points appear: a square at each corner, a bar at the middle of each edge, a ring at the centre, a crosshair at the centre of a round feature. The one a click would take turns amber.
3. Click a point on one part, then a point on another.

The constraint is created holding the distance the two parts already stand at, so making one never moves anything — and the keyboard goes straight to its first number, so you can type the figure you actually wanted without reaching for the mouse.

Or drag the second part into place. Instead of clicking the second point, press on it and drag. The part moves with the dimension reading out live on the canvas, and letting go creates the constraint holding wherever you dropped it. Grid snap, object snap and Shift to lock an axis all work exactly as they do for an ordinary drag — so you can dial an offset in by eye and then type the round number into the row.

The tool stays on, so a row of holes is two clicks each. Escape drops a half-made constraint; Escape again — or Finished — leaves the tool.

Four holes held 20 mm in from the corners of a plate. Each dimension draws as an L — the X leg and the Y leg, each labelled beside its own leg — and each constraint is one line in the panel. Resize the plate and the holes stay 20 in from the corners; the whole chain is one chip in the Objects strip.

The row#

One line per constraint, in the Constraints section:

X / Y or Dist / ∠ is set by the toggle beside the Constrain button and applies to the next constraint you make. X and Y is how a hole in the corner of a plate is dimensioned; a distance and an angle is how a linkage, a bolt circle or a gear train is.

Holding a part off the stock#

Select a single part and the section offers Left, Right, Bottom and Top: hold it where it now stands relative to that edge of the stock. The stock is ground — nothing moves it, and a part pinned to an edge wins even over a drag, which is what makes "20 mm in from the left, whatever else happens" mean what it says. An angle against an edge means nothing (the point on the edge slides with the part), so a stock constraint holds a distance only.

What moves what#

There is no root. Drag any part of a chain and the rest follow it — the solve starts from whatever you just moved. Typing a number is the one case that has to pick a side: it holds the first part and moves the second, and the arrowhead on the dimension line is what says which is which.

The panel tells you the reach before you start: "Dragging this moves 3 other parts with it", and "Held to the stock — it will not move."

Turned parts#

Every number is measured in the first part's own frame, and every anchor is a corner of that part's box measured the same way. So X 10, Y 10 from a plate's top-right corner means 10 mm in along each of its edges — rotate the plate and the holes go round with it, still 10 in from the corners. The ↻ toggle carries that the last step: with it on, the held part turns as well as moves, which is what a slot or a label needs and a round hole does not care about.

Rotation only. Stretch the plate and a typed 10 mm is still 10 mm.

When it refuses#

Over-constrained in X: Plate, Hole 3 are held by more constraints than they have room to satisfy. Delete one.

Two constraints fighting over the same freedom have no answer, so nothing is moved at all — the rows involved turn red and the parts stay put. Delete one of them. A part can be held off two different stock edges quite happily; what it cannot be is held to another part and pinned to the stock in the same direction.

Worth knowing#

• Dimensions are drawn on the canvas only while the Constrain tool is on, and then exactly the ones the panel lists. Selecting a part to give it a toolpath does not cover the geometry in dimension lines.
• Deleting a part deletes the constraints that named it, in the same step — one undo brings back both.
• A constraint moves a whole part: a gear moves with its bore and spokes, a group moves as the group.
• Constraints are saved in the .fkam file.

The pen tool#

Pen in the Draw menu places points; the tool decides what curve runs through them.

• Click places a point.
• Click-drag in Bezier mode pulls out curve handles.
• Alt-click makes the incoming segment straight, whatever mode you're in.
• Click near the first point closes the path.
• Escape finishes it open — two points minimum.
• Ctrl+Z takes back the last point placed, without leaving the tool.

Five curve modes sit under the tool, and they change what the same set of points means:

Except in Bezier mode you don't drag handles at all; you place points and the curve follows. Change mode after the fact and the same points give a different path.

Point editing#

Double-click any path to edit it point by point. This works on anything — a pen path, an imported SVG, a shape whose parameters you've given up.

Anchors sit on the path; the grey dots on stalks are the Bezier handles that set the curve into and out of each one. The first point is drawn in white, so you can always tell where the path starts — which matters when you care where a cut begins. The banner names the gestures, and the status bar reads Mode: Edit Points until you finish.

Ctrl+Z inside a point-edit session undoes just that session's edits, one at a time, before it starts eating anything else. You can go into a path, make a mess, back out of it, and leave without having disturbed the rest of the project.

Reshaping with Path Tools#

The Path Tools row, in the CAM Operations panel, makes new geometry from existing geometry rather than cutting anything. All five are re-editable afterwards from their chip in the Objects strip — the chip holds the parameters, so you can change your mind rather than undoing and redoing.

Boolean#

Select two or more paths and pick Union (merge them), Intersect (keep only where they overlap) or Subtract (cut the rest away from the first).

Selection order decides the result for Subtract, and it's pick order, not stacking order: the path you clicked first is kept, the others are cut away from it. The form's chips are labelled to match — primary (kept) for the first pick, tool (cut away) for the rest — so you can see which way a subtract will go before applying it.

The result is a new path; the sources aren't deleted, only hidden, so nothing is lost if you undo. Click the result's chip to reopen Edit Boolean, where you can swap the operation — union to subtract, say — without re-picking the sources.

Union highlighted, with the two source shapes still showing their own selection handles on canvas.

Offset#

Select one or more paths and set a distance in mm — positive grows the path (outset), negative shrinks it (inset) — and a corner style: miter (sharp corners, the default), round, or square. Offsetting several paths at once applies the same distance and style to each, producing one result per source, all editable together from one chip.

Miter is tuned to keep genuinely sharp points sharp — a star or a gear tooth doesn't get its tips squared off the way a naive miter limit would — while still capping anything close to a spike. An inset larger than the shape collapses it to nothing, which the form reports as an error rather than silently returning an empty path.

A 10 mm Round outset. Round is the style that shows most clearly on a point — Miter would carry the star's own corner out to a sharp tip instead.

Pattern#

Select one path (or a group) and choose Linear or Circular.

• Linear lays out a Rows × Cols grid at the given X and Y spacing. The original is row 0, column 0 of the grid and stays exactly where it is; the tool adds the rest around it.
• Circular arrays copies at a radius from the selection's own centre, over a start/end angle — 0–360 for a full ring, narrower for an arc. Items face outward rotates each copy tangentially, the way spokes point away from a hub, instead of every copy keeping the original's orientation.

A copy is the real shape it was copied from, not a flattened outline — a patterned gear keeps its module and tooth count re-editable, and a patterned group stays one group per copy rather than merging into the group being patterned. Reworking the count afterwards reuses existing copies where it can, so anything already built on one of them (a drilled hole, an assigned operation) keeps working; a copy deleted by hand stays deleted rather than being resurrected by the next edit.

Circular, count 5, radius 30 mm, a full 360° ring. With Items face outward checked, each heart is rotated to point away from the centre rather than all five sharing the original's orientation.

Corners#

Corners is the one worth knowing about before you need it. It offers Outer Round, Inner Round, Chamfer, Dogbone and None, and you choose which corners get it rather than treating them all.

Dogbone is the CNC-specific one. A round cutter cannot cut a sharp internal corner — it leaves a radius, and a square peg then won't seat in the socket you just cut. A dogbone overcuts a small circular notch into the corner so the mating part fits. Its radius field asks for the tool radius, not a decorative size, because that is what decides how much must be relieved.

Dogbone at a 5 mm tool radius, applied to every corner. The status bar's cursor readout is from picking specific corners — leave none picked and Apply treats every sharp corner on the path.

Next#

• 3. Stock, origin and tools — the tool library, feeds and speeds
• 4. Operations — turning geometry into toolpaths