lathecode

Text format for lathe parts and other objects with circular symmetry. Defines stock dimensions and subtractions that should be made from it right-to-left just like a part is processed in a typical lathe. Allows to specify tools, pass depths and speeds. Supports conversion to GCode and STL.

Try it in the online editor.

The shape of the object is defined in segments. Each segment can be straight, angled, circular, or a B-spline, and its position is relative to the segment before it. For example, in lathecode, a simple cylinder is defined in one segment. A cylinder with a length of 7mm and a diameter of 6mm is described as:

L7 D6

A cylinder with a shoulder would be described in two segments, essentially defining two cylinders one after the other. For example:

L2 D4
L7 D6

This description represents an object with an outer diameter of 6mm, a total length of 2 + 7 = 9mm, and a shoulder on the right side 2mm wide and 1mm deep.

Stock

Stock size should be specified in the first line via radius or diameter e.g. STOCK D10 and STOCK R5 both declare the stock to have a diameter of 10mm. When stock is not specified, part maximum diameter is taken as stock diameter.

Stock can also specify an existing internal through-hole with ID or IR. For example, STOCK D10 ID4 and STOCK R5 IR2 both declare 10mm stock with a 4mm internal hole.

Cones

Instead of specifying diameter as D, specify diameter-start as DS and diameter-end as DE - or use radii as RS and RE. For a cone with a known taper angle from the centerline, provide either the start or end dimension plus A<degrees>. Positive angles increase radius from the segment start to end; negative angles decrease it. Angle-defined cones may end at the centerline, but cannot cross it.

; specify start and end diameter or radius
; MT2 to B16 arbor can be specified like
DEPTH CUT1
L80 DS14.9 DE17.78
L2 DS17.78 DE15.733; spacer
L24 DS15.733 DE14.5

; equivalent cones using a centerline angle
L80 DE17.78 A1.031
L2 DS17.78 DE15.733; spacer
L24 DS15.733 A-1.471

Spheres

; sphere with a diameter of 10mm
L5 DS0 DE10 CONV
L5 DS10 DE0 CONV

Ellipses

; whirlgig
L1 DS0 DE2 CONV
L14 DS2 DE20 CONC
L0.5 DS20 DE21 CONV
L0.5 DS21 DE20 CONV
L8 DS20 DE2 CONC
L3.1 D2

B-splines

Use BSPLINE when a profile needs a smooth freeform curve instead of a straight taper or circular CONV / CONC segment. A spline line still has a fixed horizontal L length, a start radius or diameter, and an end radius or diameter. Interior control values follow BSPLINE and pull the curve between the endpoints:

; smooth freeform outside profile
L3 D10
L24 DS10 DE22 BSPLINE D14 D26 D18 D28
L4 D28 CH0.5

Control values may be diameters (D) or radii (R). The curve starts at DS / RS, ends at DE / RE, and does not necessarily pass through the interior controls. Lathecode samples the spline into short profile chords for previewing and planning, then the planner emits ordinary linear G-code moves.

Chamfers and fillets are not currently supported for BSPLINE segments.

Fillets and chamfers

A chamfer or fillet can be added to both ends of a straight or tapered segment. Each segment owns its own end features and only uses neighboring segments to determine whether the feature turns up or down.

; M10 bolt
L20 D10 FI0.5 ; fillet on the free end and at the shoulder root
L6 D19.6 CH0.5 ; chamfer both head edges

Endpoint features can also be specified separately after DS and DE, or after RS and RE:

; M10 bolt
L20 DS10 FI0.5 DE10 CH1 ; fillet on bolt end, chamfer up between bolt and head
L6 DS19.6 CH0 DE19.6 CH0.5 ; no head chamfer where head touches shank, small chamfer on head top

CH0 and FI0 mean no feature. Chamfer and fillet sizes are measured along the segment's horizontal L distance. Combined start and end features must fit within the segment length. Each feature must also fit the adjacent radial shoulder or the neighboring straight/tapered segment at a continuous angled corner.

Chamfers and fillets are not currently supported for CONV or CONC segments.

Tools

Tool is assumed to be zeroed on the centerline, touching the stock from the right.

To use a standard cut-off tool e.g. MGMN200, specify TOOL RECT R0.2 L2 where R stands for the corner radius and L defines the width of the tool.

If you use a round insert like RPMT10, define that with TOOL ROUND R5 where R stands for corner radius.

To use a tool with a nose angle e.g. DCGT 070202, specify the tool radius, edge length, rotation and nose angle as follows:

TOOL ANG R0.2 L7.75 A30 NA55

The online editor's Tool button can fill these standard TOOL lines from known insert presets and show the same rendered tool shape used by the planner.

Depth of cut and finish pass

Default pass depth is 0.5mm and can be changed to e.g. 1mm. Default finish pass is 0.1mm.

DEPTH CUT1 FINISH0.2

Feeds and speeds

Default cutting speed is 50mm/min, parting speed 10mm/min, move speed 200mm/min. This can be adjusted with a FEED line:

FEED MOVE200 PASS50 PART10 ; speeds mm/min

Batch processing

You can define and cut more than one part:

STOCK D20

L5 R5
L3 R9
L3

L5 R5
L3 R9
L3

L5 R5
L3 R9
L3

Axis direction

By default Z increments to the left and X increments up (forward). This matches NanoEls convention but a lot of industry machines use exactly the opposite. To make the generated GCode compatible with those machines, use AXES directive:

STOCK D4
AXES RIGHT DOWN
L3 D3

Turning vs. facing

If you prefer material removal by turning instead of facing, use MODE TURN directive:

STOCK D4
MODE TURN
AXES RIGHT DOWN
L3 D3

For developers

If you'd like to edit the online editor code e.g. to modify the online editor, use npm run dev for local runs, npm test to run tests and npm run build to build the docs/index.html all-in-one editor webpage.