12.1 Inserting Components & Fixing the Base

12.1 Inserting Components & Fixing the Base

Quick Answer: On CSWA assembly items, download the zip, open each part without feature recognition, start a new assembly in MMGS, Insert Component the base part and Fix it at the origin, then insert the remaining parts bottom-up. A floating or mis-placed base wrecks mates and assembly mass/CoM—fix first, mate second.

Assembly Creation on the commercial CSWA map is 4 questions × 30 points = 120 points—50% of the entire exam. You can ace drafting and still fail if assemblies collapse. This chapter is the foundation: how components enter the FeatureManager, how the base is grounded, and how you avoid the logistics traps that cost a full 30-point item before you even open the Mate PropertyManager.

Why insert/fix is a scoring skill

Assemblies are graded on the finished constrained model—typically assembly mass, center of mass, or a multiple-choice value that only matches when every part is present, correctly located relative to the assembly origin, and mated as the drawing intends. If the base part is free to drag, if a component never got inserted, or if units are IPS while the key expects grams, you lose the item even with “correct-looking” mates on the screen.

Bottom-up assembly (the CSWA default) means parts are complete external files you insert into an assembly document. You do not redesign the parts from scratch inside the assembly during the exam; you download, open, insert, mate, modify a key parameter if asked, and measure.

Exam download and open discipline

CSWA assembly stems usually provide a zip package of part files (and sometimes a drawing PDF or images). Treat the package as sacred geometry.

Open parts WITHOUT feature recognition

When SOLIDWORKS offers Feature Recognition / FeatureWorks-style options on imported or certain download paths, decline recognition for exam parts. Open the parts so they load as the exam author saved them—with the original FeatureManager, origins, and bodies. Re-recognizing features can:

• Change feature order or fail rebuilds
• Alter sketch/feature definitions that feed mass
• Consume time you do not have
• Produce geometry that no longer matches the answer key’s volume

Rule: Open exam parts as-is. Do not “improve” them with recognition tools mid-exam.

Quick open checklist

New assembly document — MMGS first

Create File → New → Assembly (or your template workflow). Before inserting components:

1. Set Document Properties → Units to MMGS (millimeter, gram, second) unless the stem mandates another system.
2. Confirm mass display will support two decimal places for answers.
3. Know where the assembly origin and default planes (Front, Top, Right) sit—mates and CoM are relative to this frame once the base is fixed.

Trap: Building the entire assembly in IPS, then “remembering” to convert mass at the end. CSWA keys do not forgive unit-system mass errors. Set MMGS at assembly creation, the same way you do for parts.

Inserting the first (base) component

Insert Component workflow

1. Insert → Component → Existing Part/Assembly (or the Assembly toolbar Insert Components command).
2. Browse to the base part the drawing treats as ground (often the largest plate, frame, or housing).
3. Click in the graphics area—or use the option to place at the origin if offered—so the part lands predictably.
4. Immediately Fix the component if it is not already fixed.

Fix to origin — zero free DOF on the ground part

A newly inserted component is usually floating (can translate and rotate). On CSWA you almost always Fix the first component:

• Right-click the component in the FeatureManager or graphics area → Fix.
• Fixed components show (f) after the name in the tree.
• Fixed status removes all 6 degrees of freedom for that instance relative to the assembly.

Why fix at the origin matters:

If the problem drawing shows the base aligned with standard orthographic views about the origin, place and fix so the base’s default planes align with the assembly planes unless the stem says otherwise. Do not leave the base floating “to mate later”—you will waste minutes chasing a moving target.

Float vs Fix vs Mate to origin planes

• Fix (f): Instant ground. Preferred for CSWA base parts.
• Float (-): Free until mates constrain it. Use for non-base components.
• Mate first component to assembly planes (coincident Front/Top/Right): Valid advanced technique, but slower and easier to mis-align under exam pressure. Fix is the CSWA default habit unless a prompt forces plane mates for a reason.

Bottom-up insert of remaining components

With the base fixed:

1. Insert Components for each remaining part in a sensible order (often shaft → bushings → fasteners last, or follow the drawing BOM order).
2. Drop them near their intended location—not across the room—so selection is easy.
3. Leave them floating until mates lock them.
4. Watch the FeatureManager: every required part must appear once (or the instance count the drawing shows).

Bottom-up vs top-down (exam expectation)

Stay bottom-up: insert finished parts, apply standard mates, measure.

Component instance names and tree hygiene

• Instances appear as PartName<1>, PartName<2>, …
• Fixed base: BasePlate<1>(f)
• Underdefined floaters show (-) until mates fully constrain them
• Fully defined components show (f) only if fixed, or appear without the floating marker when mates lock all DOF (display conventions vary slightly by version; the important check is drag test—a fully constrained non-fixed part should not translate/rotate freely)

Suppress nothing the drawing needs. Do not hide a part and forget it is still in the mass total—hidden components still contribute to mass unless excluded by special options you should not invent on exam day.

Materials and mass readiness at insert time

Assembly mass is the sum of component masses (given densities and volumes). Before deep mating:

• Confirm each part has the material the stem specifies (some zips already have materials; some require you to apply them).
• If one part is missing material, assembly mass is wrong even with perfect mates.
• Re-check materials after any “replace component” or edit-part detour.

Worked exam sequence (insert/fix only)

Stem sketch: Zip contains Base.sldprt, Shaft.sldprt, Bracket.sldprt. MMGS. Assembly mass after mates. Base is the large plate at the origin in the isometric.

1. Unzip → open three parts without feature recognition → glance materials.
2. New Assembly → MMGS.
3. Insert Base → place at origin → Fix → verify (f).
4. Insert Shaft and Bracket nearby, leave floating.
5. Only now open Mate (next sections) — concentric shaft-to-hole, coincident faces, etc.
6. After mates, Mass Properties at assembly level.

Common insert/fix failures

Pre-mate gate (do not skip)

Before investing ten minutes in mates, confirm:

1. All required components appear in the FeatureManager.
2. Base shows Fixed (f) and sits where the drawing’s ground should sit.
3. Units are MMGS (or stem units).
4. Materials match the problem for every part that needs density.
5. No unexplained suppressed or excluded components.

A clean insert/fix foundation makes standard mates (12.2), distance/angle/tangent mates (12.3), and DOF diagnostics (12.4) far faster—and protects the 120-point assembly block that decides most CSWA attempts.