Leta

Assembly

An assembly is a document of its own that places parts and sub-assemblies with mates and joints, runs them as mechanisms, and keeps the bill of materials. Its tabs are Assembly, Mechanism, Routing, Analysis and View.

Components

Parts and sub-assemblies go in rigid or flexible, nested to any depth, and a part inside a sub-assembly is worked on as a part.

Leta's assembly window showing a CoreXY 3D printer with an aluminum frame, gantry, toolhead and bed, and a model tree listing its groups and screw patterns
A CoreXY 3D printer of 271 components, its tree grouped by system.
Leta's assembly window showing a go-kart with yellow bodywork, a tube frame, seat, radiator and engine, with a tree of its sub-assemblies
A shifter kart built from sub-assemblies: chassis, engine and gearbox, steering, brakes and bodywork.
  • Insert parts and sub-assemblies in the configuration wanted
  • New Part placed on a clicked face, corner, hole or coordinate system, its first sketch open there
  • Edit in Place, with sketches that take other parts' edges
  • Replace a component, its mates finding their references again
  • Place Again and Duplicate
  • Components already placed saved as a sub-assembly with their mates
  • Move and rotate within what the mates allow; the freedoms left shown in the tree
  • Groups in the tree, and a flowchart of components and their mates

Mates

Mates go to faces, edges, points, datums and a part's own origin and coordinate systems, each with a flip. A broken or conflicting mate is named, and a lost reference is offered the nearest one like it.

Leta's mate editor listing a cam relation between a cam ring and a tappet roller, with the cam ring's lobed track highlighted inside a radial engine
Editing a cam mate: a tappet's roller follows the lobes of the engine's cam ring.
  • Coincident, parallel, perpendicular, tangent, concentric, distance, angle and lock
  • Symmetric, width, profile center, path and linear coupler
  • Hole Pattern: a part held by its mounting holes
  • Ctrl+click two parts for a menu of the mates that fit
  • Diagnose lists conflicting and broken mates
  • Parameters, relations and units of the assembly's own

Mechanisms and motion

Joints and couplings make an assembly move as the real machine does. Drag a part and the mechanism follows; drive a joint with a motor and run a motion study.

The radial engine sample's crank train and valve gear, run by its motion study.
A CoreXY toolhead moving on its gantry, both belts following it round their pulleys.
  • Joints: fastened, revolute, slider, cylindrical, ball, planar and pin slot, with limits
  • Couplings: gears, rack and pinion, screws, cams, slots, universal joints and belts
  • Drag a part and the mechanism follows, with collisions highlighted
  • Motion studies: motors drive joints over time, stopping at a collision if asked
  • Plots of one joint against another or against time, saved as CSV
  • Section views that follow the parts as they move
Mechanisms and motionJoints, couplings, motion studies and plots, with clips of the samples running.Mechanisms and motion

Exploded views

An exploded view is a list of steps that move or turn parts, with dashed trails back to where they came from. Explode and Collapse play the steps in turn, and drawings show them.

Leta's assembly window with a 3D printer's toolhead in an exploded view, its extruder motor, drive gear, fan, shroud, blower, duct, hotend, heater block, nozzle and screws pulled apart along dashed trails
An exploded view of the CoreXY printer's toolhead.
A seven-cylinder radial engine exploded step by step along its own axes, then put back together.

Belts and chain

A belt is laid round pulleys clicked in the order it runs, closed or with its ends clamped to a carriage, and then drives them. Roller chain sits in the sprockets' teeth in whole links.

Leta editing a timing belt, seen from above: the strip's Belt, Runs, Pulleys, First End, Last End, Offset, Length and Motion cards, and a 3D printer's CoreXY belt lit round five numbered pulleys, its ends clamped to the toolhead, its length of 1738.5 millimeters shown beside it
One of a CoreXY printer's two belts, laid round five pulleys in the order it runs, its ends clamped to the toolhead.
  • Timing belts in eight pitches, flat belts and round belts
  • The belt's length and tooth count, and the pulleys and carriages it drives
  • Roller chain in ANSI and ISO sizes, its rollers in the sprocket teeth
  • Chain in whole links, with the slack and how far to move a sprocket
Belts and chainLaying a belt or chain, the sizes, and the mechanisms they drive.Belts and chain

Routing

Pipe, tube, hose and cable run out of ports and through holes along their axes, kept in a route assembly beside the main one, and are laid again when the parts they pass through move.

A hose laid by clicking its ports and the clamp it passes through. When the clamp moves, every hose through it is laid again.
  • Pipe in Schedules 10, 40 and 80 with long-radius elbows, and a cut list
  • Bent tube with a bend table for the bender
  • Hose and cable, with the tightest bend shown and Relax to ease a hose
  • Wire harnesses: connectors with named pins, bundles with breakouts, and a wire list in and out as CSV
RoutingPipe, tube, hose, cable and wire harnesses.Routing

Hardware library

Insert Hardware places standard parts from a library of 101 families in metric and inch sizes, compiled from manufacturers' and distributors' published catalogs. One click on a hole's edge seats a screw, nut, washer, bearing or pulley.

An assembly of hardware library parts in Leta: stepper motors, a lead screw and nut, T-slot extrusions, linear rails and carriages, timing pulleys and idlers, ball bearings and bushings, a fan and a blower, screws, set screws, pins, inserts, nuts, T-slot nuts and a corner bracket
Parts from the hardware library: stepper motors, a lead screw, T-slot extrusion, rails and carriages, timing pulleys and idlers, bearings, a fan, a blower and fasteners.
  • Screws, nuts, washers, pins, keys, retaining rings, rivets, inserts, spacers and standoffs
  • Timing pulleys, idlers and roller chain sprockets
  • Ball bearings, bushings, linear shafts, rails and lead screws
  • Stepper motors, fans and blowers
  • T-slot extrusion, T-slot nuts and corner brackets
  • Change Hardware swaps size, style or material and keeps the mates
Hardware libraryAll 101 families, and how each is chosen and placed.Hardware library

Patterns and assembly features

  • Linear and circular component patterns
  • Pattern Driven: bolts placed in every hole of a part's own pattern
  • Mirror, with true opposite-hand parts
  • Datum planes, axes, points and coordinate systems of the assembly's own
  • Holes through several parts at once, and Cut Out, kept in the assembly or written into the parts

Checks and the bill of materials

Leta's interference dialog listing three lead screw and nut overlaps with their volumes, one marked in red under the printer's bed
An interference check lists every overlap with its volume and marks the selected one on the model.
  • Interference and clearance checks
  • Measure and mass properties, each part weighed by its own material
  • Section views, each part's cut face hatched, saved in the tree
  • Bills of materials, top level, parts only or indented, to CSV or Excel
  • STEP, STL, 3MF, OBJ and IGES export, and Pack and Go

Large assemblies

Each part carries its own picture and mass properties, so an assembly of hundreds of parts opens, draws, weighs and solves in seconds without building them.

  • Partial Reps: each component complete, lightweight, left out, or replaced by a box, a simpler picture or another part
  • Display states: which parts are shown, how see-through and what color
  • Config tables: components in or out, part files swapped, mate values and sub-assembly configurations, a column each
  • Drags solved in the background

See it on your own parts

Beta builds go out by email. Say what you design and what you use now.

Ask for the beta Licensing