Tutorial U: Volume claims and assembly clearance

Source	NX’s Assembly Clearance (Analysis › Assembly Clearance › Perform Analysis; the Clearance Browser; soft, touching, hard and containment interferences); the layout is ours
You learn	Volume Claim, keep-out, Check Volume Claims, Clearance Analysis, the clearance zone, Study Interference, Exclude Pair
Sizes	A 400 × 300 × 20 frame; a 150 × 150 × 60 stage; a Ø60 sensor housing; a 40 × 10 × 60 cable bracket; a Ø6 dowel; an M4-sized cover screw

Step by step

1. The layout and its claims

The parts are made by script: boxes and cylinders stand in for the modules. For each module select its parts and click Assemblies › Volume Claim, then type the owner, the size and the corner:

Claim	Members	Space
Structure	frame, dowel	400 × 300 × 20 at 0, 0, 0
Stage	stage	180 × 170 × 80 at 30, 30, 20
Sensor	housing, cover screw, cable bracket	100 × 100 × 120 at 250, 100, 20
Optics (keep-out, margin 2)	none	60 × 20 × 20 at 190, 140, 90: the beam path

Claim

Members

Space

Structure

frame, dowel

400 × 300 × 20 at 0, 0, 0

Stage

stage

180 × 170 × 80 at 30, 30, 20

Sensor

housing, cover screw, cable bracket

100 × 100 × 120 at 250, 100, 20

Optics (keep-out, margin 2)

none

60 × 20 × 20 at 190, 140, 90: the beam path

2. Check Volume Claims

Assemblies › Check Volume Claims finds four problems:

the stage’s claim and the beam path’s keep-out share space (OVERLAP);
the cable bracket sticks out of the sensor’s claim (OUTSIDE);
it enters the stage’s claim and the beam path (INTRUSION, twice).

The offending volumes are drawn in red.

3. Fixed by the owners

The optics designer raises the beam path to 110 mm; the sensor team moves its bracket into its own claim. Check Volume Claims again: no findings.

4. Assembly Clearance

With nothing selected, Assemblies › Clearance Analysis: a clearance set of every part. Clearance zone 3 mm, Perform Analysis:

Pair	Kind	Why
cover screw / sensor housing	hard	the screw is modelled without its tapped hole: 4 mm penetration
dowel / frame	containment	the dowel is modelled inside the frame, without its hole
stage / frame, sensor housing / frame	touching	they stand on the frame
cable bracket / sensor housing	soft	2.4 mm apart, inside the 3 mm zone

Pair

Kind

Why

cover screw / sensor housing

hard

the screw is modelled without its tapped hole: 4 mm penetration

dowel / frame

containment

the dowel is modelled inside the frame, without its hole

stage / frame, sensor housing / frame

touching

they stand on the frame

cable bracket / sensor housing

soft

2.4 mm apart, inside the 3 mm zone

5. Study, restore, exclude

Pick the dowel’s row and click Study Interference: only the dowel, the frame and the interference volume stay shown. Restore Visibility brings the rest back. The screw’s thread engagement is intended: pick its row and click Exclude Pair. The analysis runs again; the hard interference is listed as Gone, and the rule stays in the set for the next run.

Study Interference on the dowel in the frame

The replay

#	In the book (NX)	In FreeCAD NX-Style	Result	Notes
U1	The layout: frame, stage, sensor housing with its cover screw and cable bracket, a dowel	modelled by script (the exercise is the space management)	same	boxes and cylinders stand in for the modules' parts
U2	Claim for the structure: frame and dowel	Frame, Dowel selected + ribbon 'Assemblies › Volume Claims > Volume Claim'; owner, size, corner typed; MB2 = OK	differs	Claim Structure: Keep-in, 400 x 300 x 20 at (0, 0, 0); NX has no volume claims (its Assembly Clearance checks parts against parts)
U3	Claim for the stage module	Stage selected + ribbon 'Assemblies › Volume Claims > Volume Claim'; owner, size, corner typed; MB2 = OK	differs	Claim Stage: Keep-in, 180 x 170 x 80 at (30, 30, 20); NX has no volume claims (its Assembly Clearance checks parts against parts)
U4	Claim for the sensor module: housing, cover screw, cable bracket	Sensor housing, Cover screw, Cable bracket selected + ribbon 'Assemblies › Volume Claims > Volume Claim'; owner, size, corner typed; MB2 = OK	differs	Claim Sensor: Keep-in, 100 x 100 x 120 at (250, 100, 20); NX has no volume claims (its Assembly Clearance checks parts against parts)
U5	Keep-out for the optical path, with a 2 mm margin	nothing selected + ribbon 'Assemblies › Volume Claims > Volume Claim'; owner, size, corner, margin typed; MB2 = OK	differs	Claim Optics: Keep-out, 60 x 20 x 20 at (190, 140, 90), margin 2.0; NX has no volume claims (its Assembly Clearance checks parts against parts)
U6	Check Volume Claims	ribbon 'Assemblies › Volume Claims > Check Volume Claims'	differs	Cable bracket (Claim Sensor) enters Claim Stage: 6000.0 mm³; Cable bracket sticks out of Claim Sensor: 24000.0 mm³ outside; Cable bracket (Claim Sensor) enters Claim Optics or its 2 mm margin: 4800.0 mm³; Claim Stage and Claim Optics claim the same 4000.0 mm³. The offending volumes are drawn in red
U7	The optics designer raises the beam path to 110 mm; the sensor team moves its cable bracket into its own claim	the keep-out’s and the bracket’s Placement	differs	in NX the bracket would be moved with Move Component; the claim’s placement is a property
U8	Check Volume Claims again: every part inside its claim, no intrusion, no space claimed twice	ribbon 'Assemblies › Volume Claims > Check Volume Claims'	differs	no findings
U9	Assemblies > Clearance Analysis: a clearance set of every part, zone 3 mm, Perform Analysis	ribbon 'Assemblies › Clearance Analysis > Clearance Analysis', 3 typed, 'Perform Analysis'	differs	{'hard': 1, 'containment': 1, 'touching': 2, 'soft': 1}; Cable bracket/Sensor housing soft (2.39 mm); Cover screw/Sensor housing hard (penetration 4.00, 62.8 mm³); Dowel/Frame containment (penetration 6.00, 424.1 mm³); Frame/Sensor housing touching (0.00 mm); Frame/Stage touching (0.00 mm). NX: the same four kinds; FreeCAD had only Part > Check Geometry and booleans
U10	Study Interference on the dowel in the frame, then Restore Visibility	row picked in the browser + 'Study Interference', 'Restore Visibility'	same	shown while studying: ['Clearance interferences', 'Dowel', 'Frame']; NX: MB3 > Study Interference and Restore Component Visibility
U11	Exclude Pair: the screw’s thread engagement is intended; the analysis runs again	hard row picked + 'Exclude Pair'	same	{'hard': 0, 'containment': 1, 'touching': 2, 'soft': 1}; gone since the last run: [{'gone': 'Part003\|Part004'}]; the rule ['Part003\|Part004=exclude'] is kept in the set’s PairRules by object name (a renamed part keeps it), so the next check after a design change skips it too
U12	OK: the clearance report	MB2 = OK	same	the clearance set stays in the Part Navigator; double-click it to run it again

In the book (NX)

In FreeCAD NX-Style

Result

Notes

The layout: frame, stage, sensor housing with its cover screw and cable bracket, a dowel

modelled by script (the exercise is the space management)

same

boxes and cylinders stand in for the modules' parts

Claim for the structure: frame and dowel

Frame, Dowel selected + ribbon 'Assemblies › Volume Claims > Volume Claim'; owner, size, corner typed; MB2 = OK

differs

Claim Structure: Keep-in, 400 x 300 x 20 at (0, 0, 0); NX has no volume claims (its Assembly Clearance checks parts against parts)

Claim for the stage module

Stage selected + ribbon 'Assemblies › Volume Claims > Volume Claim'; owner, size, corner typed; MB2 = OK

differs

Claim Stage: Keep-in, 180 x 170 x 80 at (30, 30, 20); NX has no volume claims (its Assembly Clearance checks parts against parts)

Claim for the sensor module: housing, cover screw, cable bracket

Sensor housing, Cover screw, Cable bracket selected + ribbon 'Assemblies › Volume Claims > Volume Claim'; owner, size, corner typed; MB2 = OK

differs

Claim Sensor: Keep-in, 100 x 100 x 120 at (250, 100, 20); NX has no volume claims (its Assembly Clearance checks parts against parts)

Keep-out for the optical path, with a 2 mm margin

nothing selected + ribbon 'Assemblies › Volume Claims > Volume Claim'; owner, size, corner, margin typed; MB2 = OK

differs

Claim Optics: Keep-out, 60 x 20 x 20 at (190, 140, 90), margin 2.0; NX has no volume claims (its Assembly Clearance checks parts against parts)

Check Volume Claims

ribbon 'Assemblies › Volume Claims > Check Volume Claims'

differs

Cable bracket (Claim Sensor) enters Claim Stage: 6000.0 mm³; Cable bracket sticks out of Claim Sensor: 24000.0 mm³ outside; Cable bracket (Claim Sensor) enters Claim Optics or its 2 mm margin: 4800.0 mm³; Claim Stage and Claim Optics claim the same 4000.0 mm³. The offending volumes are drawn in red

The optics designer raises the beam path to 110 mm; the sensor team moves its cable bracket into its own claim

the keep-out’s and the bracket’s Placement

differs

in NX the bracket would be moved with Move Component; the claim’s placement is a property

Check Volume Claims again: every part inside its claim, no intrusion, no space claimed twice

ribbon 'Assemblies › Volume Claims > Check Volume Claims'

differs

no findings

Assemblies > Clearance Analysis: a clearance set of every part, zone 3 mm, Perform Analysis

ribbon 'Assemblies › Clearance Analysis > Clearance Analysis', 3 typed, 'Perform Analysis'

differs

{'hard': 1, 'containment': 1, 'touching': 2, 'soft': 1}; Cable bracket/Sensor housing soft (2.39 mm); Cover screw/Sensor housing hard (penetration 4.00, 62.8 mm³); Dowel/Frame containment (penetration 6.00, 424.1 mm³); Frame/Sensor housing touching (0.00 mm); Frame/Stage touching (0.00 mm). NX: the same four kinds; FreeCAD had only Part > Check Geometry and booleans

U10

Study Interference on the dowel in the frame, then Restore Visibility

row picked in the browser + 'Study Interference', 'Restore Visibility'

same

shown while studying: ['Clearance interferences', 'Dowel', 'Frame']; NX: MB3 > Study Interference and Restore Component Visibility

U11

Exclude Pair: the screw’s thread engagement is intended; the analysis runs again

hard row picked + 'Exclude Pair'

same

{'hard': 0, 'containment': 1, 'touching': 2, 'soft': 1}; gone since the last run: [{'gone': 'Part003|Part004'}]; the rule ['Part003|Part004=exclude'] is kept in the set’s PairRules by object name (a renamed part keeps it), so the next check after a design change skips it too

U12

OK: the clearance report

MB2 = OK

same

the clearance set stays in the Part Navigator; double-click it to run it again

Result	Means
same	The book’s NX steps work as written.
differs	It works, but the FreeCAD way is different; the notes say how.
limit	The book’s way fails in FreeCAD itself; a workaround follows in the next steps.
missing	FreeCAD has no such function; a stand-in follows.
skipped	Not replayed; the notes give the reason.
FAILED	Did not work.

Result

Means

same

The book’s NX steps work as written.

differs

It works, but the FreeCAD way is different; the notes say how.

limit

The book’s way fails in FreeCAD itself; a workaround follows in the next steps.

missing

FreeCAD has no such function; a stand-in follows.

skipped

Not replayed; the notes give the reason.

FAILED

Did not work.

What differs from NX

NX has no volume claims; they are NX-Style’s.
NX’s clearance zones can also be set per component and per pair in the dialog; here per pair with PairRules.
NX moves a component with Move Component; here its placement is changed.