Assemblies

An assembly places parts and other assemblies as components and holds them together with mates. Assemblies are saved as .rasm files and open in a tab of their own.

Starting an assembly

File ▸ New Assembly, or New Assembly in the start window. Every assembly has the standard Front, Top and Right Planes and the Origin at the top of its tree. They show in the view as a part's do (the eye in the tree, View ▸ Show Planes), and mates can use them; they stay where they are.

The Assembly tab of the ribbon holds Insert Components, Mate, Fix, Float, Hide Component, Suppress, Open Part, Exploded View, Explode / Collapse, Bill of Materials, Interference Check and Zoom to Fit.

Inserting components

Insert Components lists the parts and assemblies open in other tabs, or Browse for a Part or Assembly… takes a .rcad or .rasm file.

• The first component is fixed at the origin; the others are placed beside what is there.
• If the part has configurations, you choose which one to use. Right-click a component later to switch it to another configuration. The same part can be in the assembly several times in different configurations.
• The assembly keeps a copy of each part, refreshed from its tab or file whenever you come back to the assembly, so edit a part and the assembly follows.
• Several instances of one part share it: it is built once and drawn once.

Mates

Click Mate (M), then two faces, edges or vertices on different components (or a standard plane), choose the type and click ✔. The panel stays open for the next mate; Esc closes it.

• Flat faces count as planes; cylinders, cones and circular edges as axes; spheres and vertices as points.
• Each mate is shown applied while you choose. Flip swaps Aligned / Anti-Aligned (or the side for Distance and Tangent). When the alignment chosen from how the faces sit can't be reached, the other one is used.
• A mate that conflicts with the others is refused with a message.
• A mate keeps its faces and edges by their geometry, not only by their number in the part. When a part gets a new feature or a dimension moves a face, the mate stays on the same face. A mate whose face or edge is gone gets a red ! in the tree ("1 mate lost a face"). Tools ▸ Fix Mates… lists them with Edit, Suppress and Delete.

Gear and rack-pinion mates

These relate one component's motion to another's, from where they are when the mate is made, so set the teeth in mesh first. Hold each gear on its axle with the usual mates (Concentric and Coincident); the gear mate then takes one more degree of freedom.

• Gear: turn one gear and the other turns the other way, in the ratio of their radii. Ratio is how many turns entity 2 makes per turn of entity 1; change it to the teeth ratio if the cylinders are not the pitch circles. Reverse the direction is for an internal gear, where both turn the same way. The tree shows it as for example "Gear1 1:2".
• Rack Pinion: turning the pinion slides the rack along the edge (or face) picked, and sliding the rack turns the pinion. Rack travel per pinion turn starts as the pinion's circumference (π × diameter). Reverse changes the direction.
• They follow turns of any size made step by step, as when you drag a gear. One jump of more than half a turn can't be told from a turn the other way.

Moving components

Left-drag a component to move it, Alt+drag to turn it. It moves only as its mates allow. The view turns, pans and zooms as in a part (see Navigating the 3D View).

Selecting works as in a part and follows the selection filter: with no filter a click picks the vertex, edge, face or plane under the cursor; with the Bodies filter it picks whole components. Ctrl+click adds or takes away. Right-click a face, edge or vertex for Mate… and the component's commands; whatever is selected goes into the mate. Dragging a component moves it, whatever is selected.

The assembly tree

• Each component shows (f) when fixed or (-) while still free to move, its configuration, and an eye to hide or show it.
• The Mates folder lists the mates; right-click one for Edit, Flip, Suppress or Delete.
• Right-click a component for Mate…, Open Part (or double-click it), Fix / Float, Hide / Show, Suppress / Unsuppress, Insert Another Instance, Rename and Delete.
• Undo and redo work in the assembly.

Sub-assemblies

An assembly can hold other assemblies as components. Insert Components ▸ Browse for a Part or Assembly… takes a .rasm file, and STEP assemblies keep their sub-assemblies when they open as an assembly. An assembly can't go inside itself.

• A sub-assembly is kept whole, with its own parts, placements and configurations, and moves, hides, suppresses and explodes as one. Clicking any of its parts picks it.
• Mates can use the faces, edges and vertices of the parts inside it.
• In the tree, ▶ opens a sub-assembly to show its components. Double-click one, or right-click the sub-assembly ▸ Open Sub-assembly, to change it in its own tab; the changes come back to the assembly.

Exploded views

Exploded View on the ribbon (or Insert ▸ Exploded View…) spreads components apart for display; the model and its mates stay put.

1. Click components to pick them (click again to drop one).
2. Pick a direction: ±X, ±Y, ±Z, or along a face's normal.
3. Drag the picked items along the direction, or type the distance, then click Add Step. Spread Out spaces the picked items out along the direction, one step each.
4. Click a step to change it, ✕ to delete it. Explode lines (dashed, from each item's place to where it is shown) can be switched off.

The tree's Exploded Views folder lists them. Double-click one to explode or collapse it (animated); right-click for Explode / Collapse, Animate, Edit, Rename and Delete. The Explode / Collapse button on the ribbon does the same for the last one. Dragging a component, adding a mate or editing collapses the view first. Exploded views are saved with the file.

Interference Check

Interference Check (Assembly tab, or Tools ▸ Interference Check…) finds where components overlap. Each overlap shows in red and is listed with its two components (inside sub-assemblies as "Sub-assembly ▸ Part") and its volume. Faces that only touch, such as mated faces, are not counted, and nor are the bodies of one multi-body part against each other. An exploded assembly is collapsed first, so the check is of where the mates put the parts.

Bill of Materials

Bill of Materials lists the parts with their quantities and materials: one row per part and configuration used, with suppressed components left out. It is indented: a sub-assembly's parts are listed under it (1.1, 1.2…), with the quantities in one of it. Copy as CSV or Save CSV… takes it to a spreadsheet.

STEP assemblies

Opening a STEP file that holds an assembly asks whether to open it as an assembly or as one part (see Importing in the Working with Files chapter). As an assembly, each part of the file becomes a part, each sub-assembly a sub-assembly, and each component is placed, fixed, where the file places it, with the names and colours from the file.

Saving parts as separate files

When an assembly holds parts or sub-assemblies that are only inside it (as a STEP assembly does when it opens), Save asks how to save them:

• Save Parts as Separate Files saves each part as a .rcad file and each sub-assembly as a .rasm file in the assembly's folder, named after them. The assembly (and each sub-assembly) then uses those files, so each part can be opened and changed on its own and the change shows in the assembly. A part used in several places is one file. If files of those names are already there, you are asked before they are replaced.
• Save as One File keeps everything inside the assembly file. You are not asked again, except on Save As.

Big assemblies

Each part an assembly builds is kept in the model cache (%LOCALAPPDATA%\RazorCAD\modelcache). Opening the assembly again shows unchanged parts straight from there, and the kernel only builds parts that changed, so a large layout reopens in seconds. Each part is sent to the graphics card once and placed at every component that uses it, so moving, hiding or exploding components is instant.