Tutorial AY: Die Cavity

Source	Ming C. Leu, Wenjin Tao, Amir Ghazanfari and Krishna Kolan, NX 12 for Engineering Design (Missouri University of Science and Technology), exercise 4.10.4 (Die Cavity).
You learn	Block with Unite and Subtract, a sketch with a Studio Spline through typed points, Revolve (Subtract) about a sketch line, Cylinder with Unite, Edge Blend
Sizes	the book’s, in millimetres.

The book draws the section’s spline through four points and gives the posts as "20 inches" in a millimetre part; they are Ø20 mm here. Its pictures put R10 on the top block’s four vertical outer edges and R5 on the posts' top edges, which is what the replay blends.

Step by step

1. The blocks

Create a new part, Die_cavity, in mm. Choose Block, type the origin (−75, −50, −80) and the lengths 150 × 100 × 40, and click OK. Choose Block again: origin (−50, −40, −40), 100 × 80 × 40, Boolean Unite: the top block, centred.

2. The section

Click Sketch and pick the XZ plane. With Line (L) draw (50, 0) to (50, 30), then to (−50, 30), then to (−50, 0); type each point in the X and Y fields. Press S (Studio Spline, Through Points) and type (−50, 0), (−25, 1), (25, −8) and (50, 0); MB2 ends it. The section is now closed. Draw one more line from (−75, −100) to (75, −100): the revolve axis, 60 mm below the first block’s top. Finish the sketch with Ctrl+Q.

3. The curved top

Click Revolve (Subtract), set the Curve Rule to Single Curve and pick the section’s four curves. Under the axis choose Line… and pick the axis line. Type End 45 and Start −45, and click OK: the top block’s top now follows the spline.

4. The cavity and the posts

Choose Block: origin (−35, −25, −30), 70 × 50 × 30, Boolean Subtract: the cavity. Choose Cylinder, Axis, Diameter, and Height, vector ZC: Ø20 × 15 at (−35, −25, −30), Boolean Unite. Repeat at (−35, 25), (35, −25) and (35, 25): a post in each corner of the cavity.

5. The blends

Select the top block’s four vertical outer edges and click Edge Blend; type 10 and press MB2. Select the four posts' top edges and blend them with 5.

Save the part.

The replay

#	In the book (NX)	In FreeCAD NX-Style	Result	Notes
AY1	Create a new file, units mm (Die_cavity)	Ctrl+N, Model template	same	new document ['Unnamed4']; NX-Style parts are metric
AY2	Save it as Die_cavity	file name given once by script (the system file dialog is not driven); a change, then the Ctrl+S key	same	Die_cavity.FCStd rewritten by Ctrl+S: the file holds the change and the part is unmodified afterwards (modified before the key: True); FreeCAD format, not .prt
AY3	Block 150 x 100 x 40 at (-75, -50, -80)	ribbon 'Home › Feature', Type 'Origin and Edge Lengths', XC/YC/ZC -75/-50/-80 typed, length 150, width 100, height 40 typed, Boolean 'None', OK	same	same solid as the reference: 0 mm³ differ, box within 0 mm, 6 faces (6 in the reference); origin (-75.0, -50.0, -80.0); one undo step ['Block']
AY4	Block 100 x 80 x 40 on top, centred, Unite	ribbon 'Home › Feature', Type 'Origin and Edge Lengths', XC/YC/ZC -50/-40/-40 typed, length 100, width 80, height 40 typed, Boolean 'Unite', OK	same	same solid as the reference: 0 mm³ differ, box within 0 mm, 11 faces (11 in the reference); origin (-50.0, -40.0, -40.0); one undo step ['Block']; with Body
AY5	Sketch: the section (three lines and the spline through four points) and the axis line	ribbon 'Home › Direct Sketch > Sketch' on 'XZ-plane (Base plane)'; L (Line) x3 6 points typed, S (Studio Spline) 4 typed, L (Line) 2 typed (clicked: 0); MB2 after each	same	1 spline, its distance from the four points [0.0, 0.0, 0.0, 0.0] mm; the section closed True; the axis line at z = -100 mm True. The book’s reference lines (the blocks' outlines) are not drawn: they only help place the curves
AY6	Revolve (Subtract): the section’s curves, the axis line, Start -45, End 45	ribbon 'Home › Feature > Revolve (Subtract)', Curve Rule 'Single Curve', the 4 curves picked (QuickPick, click); 'Line…' + the axis line (QuickPick (the click was not taken)); Start and End typed	same	section of 4 curves; axis {'vector': 'line:Edge5', 'point': (0.0, 0.0, 0.0)}; limits (-45.0, 45.0)
AY7	OK: the top block’s surface cut to the spline, curved across	OK clicked	same	same solid as the reference: 0 mm³ differ, box within 0 mm, 12 faces (12 in the reference)
AY8	Block 70 x 50 x 30 subtracted: the cavity	ribbon 'Home › Feature', Type 'Origin and Edge Lengths', XC/YC/ZC -35/-25/-30 typed, length 70, width 50, height 30 typed, Boolean 'Subtract', OK	same	same solid as the reference: 0 mm³ differ, box within 0 mm, 17 faces (17 in the reference); origin (-35.0, -25.0, -30.0); one undo step ['Block']; with Body
AY9	Cylinder Ø20 x 15 at the cavity’s corner (-35, -25), Unite	ribbon 'Home › Feature', Type 'Axis, Diameter, and Height', Specify Vector 'ZC', XC/YC/ZC -35/-25/-30 typed, diameter 20, height 15 typed, Boolean 'Unite', OK	same	same solid as the reference: 0 mm³ differ, box within 0 mm, 19 faces (19 in the reference); origin (-35.0, -25.0, -30.0); one undo step ['Cylinder']; with Body
AY10	Cylinder Ø20 x 15 at the cavity’s corner (-35, 25), Unite	ribbon 'Home › Feature', Type 'Axis, Diameter, and Height', Specify Vector 'ZC', XC/YC/ZC -35/25/-30 typed, diameter 20, height 15 typed, Boolean 'Unite', OK	same	same solid as the reference: 0 mm³ differ, box within 0 mm, 21 faces (21 in the reference); origin (-35.0, 25.0, -30.0); one undo step ['Cylinder']; with Body
AY11	Cylinder Ø20 x 15 at the cavity’s corner (35, -25), Unite	ribbon 'Home › Feature', Type 'Axis, Diameter, and Height', Specify Vector 'ZC', XC/YC/ZC 35/-25/-30 typed, diameter 20, height 15 typed, Boolean 'Unite', OK	same	same solid as the reference: 0 mm³ differ, box within 0 mm, 23 faces (23 in the reference); origin (35.0, -25.0, -30.0); one undo step ['Cylinder']; with Body
AY12	Cylinder Ø20 x 15 at the cavity’s corner (35, 25), Unite	ribbon 'Home › Feature', Type 'Axis, Diameter, and Height', Specify Vector 'ZC', XC/YC/ZC 35/25/-30 typed, diameter 20, height 15 typed, Boolean 'Unite', OK	same	same solid as the reference: 0 mm³ differ, box within 0 mm, 25 faces (25 in the reference); origin (35.0, 25.0, -30.0); one undo step ['Cylinder']; with Body
AY13	Edge Blend R10: the outer edges (the top block’s corners)	4 edges selected + ribbon 'Home › Feature > Edge Blend', 'filletRadius' = 10 mm, MB2 = OK	same	same solid as the reference: 0 mm³ differ, box within 0 mm, 29 faces (29 in the reference)
AY14	Edge Blend R5: the inner edges (the corner posts' tops)	4 edges selected + ribbon 'Home › Feature > Edge Blend', 'filletRadius' = 5 mm, MB2 = OK	same	same solid as the reference: 0 mm³ differ, box within 0 mm, 33 faces (33 in the reference)
AY15	The die cavity	compared with the book’s dimensions built by the Part API	same	same solid as the reference: 0 mm³ differ, box within 0 mm, 33 faces (33 in the reference)
AY16	Save the part	file name given once by script (the system file dialog is not driven); a change, then the Ctrl+S key	same	Die_cavity.FCStd rewritten by Ctrl+S: the file holds the change and the part is unmodified afterwards (modified before the key: True); FreeCAD format, not .prt

In the book (NX)

In FreeCAD NX-Style

Result

Notes

AY1

Create a new file, units mm (Die_cavity)

Ctrl+N, Model template

same

new document ['Unnamed4']; NX-Style parts are metric

AY2

Save it as Die_cavity

file name given once by script (the system file dialog is not driven); a change, then the Ctrl+S key

same

Die_cavity.FCStd rewritten by Ctrl+S: the file holds the change and the part is unmodified afterwards (modified before the key: True); FreeCAD format, not .prt

AY3

Block 150 x 100 x 40 at (-75, -50, -80)

ribbon 'Home › Feature', Type 'Origin and Edge Lengths', XC/YC/ZC -75/-50/-80 typed, length 150, width 100, height 40 typed, Boolean 'None', OK

same

same solid as the reference: 0 mm³ differ, box within 0 mm, 6 faces (6 in the reference); origin (-75.0, -50.0, -80.0); one undo step ['Block']

AY4

Block 100 x 80 x 40 on top, centred, Unite

ribbon 'Home › Feature', Type 'Origin and Edge Lengths', XC/YC/ZC -50/-40/-40 typed, length 100, width 80, height 40 typed, Boolean 'Unite', OK

same

same solid as the reference: 0 mm³ differ, box within 0 mm, 11 faces (11 in the reference); origin (-50.0, -40.0, -40.0); one undo step ['Block']; with Body

AY5

Sketch: the section (three lines and the spline through four points) and the axis line

ribbon 'Home › Direct Sketch > Sketch' on 'XZ-plane (Base plane)'; L (Line) x3 6 points typed, S (Studio Spline) 4 typed, L (Line) 2 typed (clicked: 0); MB2 after each

same

1 spline, its distance from the four points [0.0, 0.0, 0.0, 0.0] mm; the section closed True; the axis line at z = -100 mm True. The book’s reference lines (the blocks' outlines) are not drawn: they only help place the curves

AY6

Revolve (Subtract): the section’s curves, the axis line, Start -45, End 45

ribbon 'Home › Feature > Revolve (Subtract)', Curve Rule 'Single Curve', the 4 curves picked (QuickPick, click); 'Line…' + the axis line (QuickPick (the click was not taken)); Start and End typed

same

section of 4 curves; axis {'vector': 'line:Edge5', 'point': (0.0, 0.0, 0.0)}; limits (-45.0, 45.0)

AY7

OK: the top block’s surface cut to the spline, curved across

OK clicked

same

same solid as the reference: 0 mm³ differ, box within 0 mm, 12 faces (12 in the reference)

AY8

Block 70 x 50 x 30 subtracted: the cavity

ribbon 'Home › Feature', Type 'Origin and Edge Lengths', XC/YC/ZC -35/-25/-30 typed, length 70, width 50, height 30 typed, Boolean 'Subtract', OK

same

same solid as the reference: 0 mm³ differ, box within 0 mm, 17 faces (17 in the reference); origin (-35.0, -25.0, -30.0); one undo step ['Block']; with Body

AY9

Cylinder Ø20 x 15 at the cavity’s corner (-35, -25), Unite

ribbon 'Home › Feature', Type 'Axis, Diameter, and Height', Specify Vector 'ZC', XC/YC/ZC -35/-25/-30 typed, diameter 20, height 15 typed, Boolean 'Unite', OK

same

same solid as the reference: 0 mm³ differ, box within 0 mm, 19 faces (19 in the reference); origin (-35.0, -25.0, -30.0); one undo step ['Cylinder']; with Body

AY10

Cylinder Ø20 x 15 at the cavity’s corner (-35, 25), Unite

ribbon 'Home › Feature', Type 'Axis, Diameter, and Height', Specify Vector 'ZC', XC/YC/ZC -35/25/-30 typed, diameter 20, height 15 typed, Boolean 'Unite', OK

same

same solid as the reference: 0 mm³ differ, box within 0 mm, 21 faces (21 in the reference); origin (-35.0, 25.0, -30.0); one undo step ['Cylinder']; with Body

AY11

Cylinder Ø20 x 15 at the cavity’s corner (35, -25), Unite

ribbon 'Home › Feature', Type 'Axis, Diameter, and Height', Specify Vector 'ZC', XC/YC/ZC 35/-25/-30 typed, diameter 20, height 15 typed, Boolean 'Unite', OK

same

same solid as the reference: 0 mm³ differ, box within 0 mm, 23 faces (23 in the reference); origin (35.0, -25.0, -30.0); one undo step ['Cylinder']; with Body

AY12

Cylinder Ø20 x 15 at the cavity’s corner (35, 25), Unite

ribbon 'Home › Feature', Type 'Axis, Diameter, and Height', Specify Vector 'ZC', XC/YC/ZC 35/25/-30 typed, diameter 20, height 15 typed, Boolean 'Unite', OK

same

same solid as the reference: 0 mm³ differ, box within 0 mm, 25 faces (25 in the reference); origin (35.0, 25.0, -30.0); one undo step ['Cylinder']; with Body

AY13

Edge Blend R10: the outer edges (the top block’s corners)

4 edges selected + ribbon 'Home › Feature > Edge Blend', 'filletRadius' = 10 mm, MB2 = OK

same

same solid as the reference: 0 mm³ differ, box within 0 mm, 29 faces (29 in the reference)

AY14

Edge Blend R5: the inner edges (the corner posts' tops)

4 edges selected + ribbon 'Home › Feature > Edge Blend', 'filletRadius' = 5 mm, MB2 = OK

same

same solid as the reference: 0 mm³ differ, box within 0 mm, 33 faces (33 in the reference)

AY15

The die cavity

compared with the book’s dimensions built by the Part API

same

same solid as the reference: 0 mm³ differ, box within 0 mm, 33 faces (33 in the reference)

AY16

Save the part

file name given once by script (the system file dialog is not driven); a change, then the Ctrl+S key

same

Die_cavity.FCStd rewritten by Ctrl+S: the file holds the change and the part is unmodified afterwards (modified before the key: True); FreeCAD format, not .prt

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.

Each step is compared with FreeCAD’s Part API build of the book’s dimensions, the section’s spline taken from the sketch.

What differs from NX

Profile (Z) shows no on-view X/Y fields in FreeCAD’s sketcher, so the replay draws the three lines with Line (L), which does.
The Revolve box resets a Start that is not valid yet: typing Start −45 while End is still 0 reads back 0. Typing End first avoids it.