Units, typed values and expressions

The tables and the two test fields on this page use the code of the app.

Display units#

KerfCraft keeps every length in millimetres. The display unit changes only how you see and type lengths. To change it, use Properties ▸ Units with nothing selected. The default is ft-in for a project in the US / Canada region, and mm for other regions. The assistant always works in millimetres.

Unit	1219.2 mm on screen	1219.7 mm in a cut list
mm	1219.2 mm	1219.7 mm
cm	121.9 cm	121.97 cm
m	1.219 m	1.2197 m
in	48"	48"+
ft-in	4' 0"	4' 0"+

In a cut list, imperial sizes go to the nearest 1/16". A + after a size means that the true size is more than 1/64" larger than shown. A - means that it is more than 1/64" smaller. The tooltip and the mm columns of the CSV file show the exact millimetres.

Typed values#

While a tool is active, type a value and press Enter. The value shows in the box in the status bar, next to the prompt of the tool.

• A number without a unit is in the display unit. With ft-in, a number without a unit is in inches.
• Units: mm, cm, m, in or ", ft or '. Spaces between the number and the unit are optional.
• Fractions: 3/4, 6 1/2". Feet and inches together: 1' 6 1/2", 2ft 3in. A number after feet is in inches.
• More than one value: separate them with ,, ;, x, ×, * or a space, for example 600,400 or 600 x 400.
• A minus sign reverses the direction: -600,400.

Typed values for each tool#

These tables are the same as the hover cards on the toolbar. For the keys of each tool, see Keyboard shortcuts.

Select tool

Type	Action
90	straight after a ring drag: change the angle (one undo)

Rectangle tool

Type	Action
600,400	width,depth the way the cursor was dragged
-600,400	width the other way
18	thickness, up or down as the cursor points
18 · 600,400 · 600,400,12	straight after: change thickness / size / both (one undo)

Line tool

Type	Action
1200	segment length along the line to the cursor. A number goes the way the cursor points; a minus reverses it.
18	after closing: thickness, the side the cursor is on
24	straight after: change the thickness (one undo)

Circle tool

Type	Action
300	radius
18	thickness, the side the cursor is on; −18 the other way
24	straight after: change the thickness (one undo)

Envelope tool

Type	Action
1620	segment length along the line to the cursor. A number goes the way the cursor points; a minus reverses it.
-1310,0,1010	an exact x,y,z offset to the next point
745	after closing: the depth (front view: going back)

Push/Pull tool

Type	Action
3000	along the face, the side the cursor is on. A number goes the way the cursor points; a minus reverses it.
-200	the other way
500	straight after a push: redo it at 500 (one undo)

Move tool

Type	Action
600	along the drag / locked axis. A number goes the way the cursor points; a minus reverses it.
600,0,300	an exact x,y,z offset
900	straight after: change the last move (one undo)
x3	straight after a copy: 3 copies in a row

Rotate tool

Type	Action
90	degrees about the axis
-45	the other way
30	straight after: change the last rotation (one undo)

Timber tool

Type	Action
2400	length along the line to the cursor. A number goes the way the cursor points; a minus reverses it.
0,0,2400	an exact x,y,z offset from the start
3000	straight after: change the last member (one undo)

Measure tool

Type	Action
1200	sets the tape to 1200 along its direction. A number goes the way the cursor points; a minus reverses it.
0,600,0	an exact x,y,z offset
900	straight after: change that tape

Project parameters#

Project parameters are named values that other values can refer to. They are in Properties ▸ Parameters with nothing selected. To add one, type name = expression in the empty field and press Enter. The panel shows the value of each parameter after =, or ? when KerfCraft cannot calculate it.

The parameters of a generated assembly, for example a bookcase, also accept expressions. They can refer to project parameters.

Expression syntax#

• Numbers: 600, 0.5, .5.
• Operators: +, -, *, / and brackets. * and / come before + and -. A minus sign before a value makes it negative.
• Names: a letter or _ first, then letters, digits or _, for example shelf_gap. A name refers to another parameter.
• A number without a unit is in millimetres. The display unit does not change this.
• Parameters can refer to each other in any order. A loop, for example a = b and b = a, is an error.
• Other errors: an unknown parameter name, an unknown function, division by zero, and a result that is not a finite number.

Units in expressions#

Put the unit after the number: 1.2 m, 2 ft.

Unit	Equals
mm	1 mm
cm	10 mm
m	1000 mm
in	25.4 mm
ft	304.8 mm

Functions#

Function	Result
min(a, b, …)	the smallest value
max(a, b, …)	the largest value
round(v, step)	v to the nearest step (step 1 when you leave it out)
floor(v, step)	v down to a step
ceil(v, step)	v up to a step
abs(v)	v without its sign
sqrt(v)	the square root of v

Test an expression#