Tutorial AT: Arbor Press Rack

Source	Ming C. Leu, Wenjin Tao, Amir Ghazanfari and Krishna Kolan, NX 12 for Engineering Design (Missouri University of Science and Technology), section 4.7.4 (Rack).
You learn	Rectangle, Extrude, a tapered cut with Extrude (Subtract), Pattern Feature (Linear, Count and Pitch), the Point Dialog’s Between Two Points
Sizes	the book’s, in inches, typed in millimetres. A rectangle from (0, 0) to (240, 25), extruded 20. A tooth space 35 long across the bar, 6 wide and 5.034 deep, its walls tapered 14.5°, its centre lines 37.8 from the end and 10 from the side. 19 of them at a pitch of 9.4. A hole Ø10, 20 deep, into the far end.

The book gives the pocket’s sizes only in its figure (p. 89); they are listed above.

Step by step

1. The bar

Ctrl+N and save the part as Arborpress_rack. End turns the view to Isometric. Click Sketch, pick the XC-YC plane and press MB2. Press R for Rectangle. Type the first corner (0, 0) in the fields beside the pointer, then the opposite corner (6096, 635) mm, which is (240, 25) in. Press MB2, then Ctrl+Q.

Click Extrude, click a side of the rectangle, and type 508 mm (20 in). Click OK.

2. One tooth space

Select the bar’s top face and click Sketch. Draw a Rectangle from (34.8, −7.5) to (40.8, 27.5) in, typed in mm. That is the book’s pocket: 6 wide along XC and 35 long across the bar, centred 37.8 from the end and 10 from the side. It runs out over both sides of the bar. Press MB2, then Ctrl+Q.

Click Extrude (Subtract), click a side of the rectangle (QuickPick lists it where it lies on the face), type the length 127.8636 mm (5.034 in) and the taper −14.5°, and click OK.

3. The teeth

Select the Extrude (Subtract) and click Pattern Feature. Choose the X axis as Direction 1, Spacing, 19 occurrences and 238.76 mm (9.4 in). Press MB2.

4. The hole

Click Cylinder and choose −XC. In Specify Point choose Between Two Points and click two opposite corners of the far end face: the point is the face’s centre. Type Diameter 254 and Height 508 mm (10 and 20 in), choose Subtract, and click OK.

The finished rack: 19 tooth spaces along the bar and the hole in its end

Save the part.

The replay

#	In the book (NX)	In FreeCAD NX-Style	Result	Notes
AT1	Create a new file (Arborpress_rack)	Ctrl+N, Model template	same	new document ['Unnamed2']
AT2	Units in the New dialog (the book picks inches)	metric part kept; book sizes typed in mm	differs	FreeCAD sets units in Preferences, not in the New dialog; NXStyle defaults to millimetres (document: Standard (mm, kg, s, °); 25.4 mm shows as 25.40 mm)
AT3	Save it as Arborpress_rack	file name given once by script (the system file dialog is not driven); a change, then the Ctrl+S key	same	Arborpress_rack.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
AT4	Rectangle: corner 1 (0, 0, 0), corner 2 (240, 25, 0)	ribbon 'Home › Direct Sketch > Sketch' on 'XY-plane (Base plane)', R key (tool True), first corner typed, opposite corner typed as X, Y, MB2	differs	4 lines; corners all at the book. NX 12’s Insert > Curve > Rectangle is a curve outside sketches; NX-Style draws it in a sketch (NX 2212: Sketch > Rectangle)
AT5	Extrude the rectangle along ZC, Start 0, End 20	ribbon 'Home › Feature > Extrude', a side picked (click; Curve Rule Inferred Curves), dialog opened True; Boolean 'None', 'lengthEdit' = 508 mm; OK clicked	same	same solid as the reference: 0 mm³ differ, box within 0 mm, 6 faces (6 in the reference)
AT6	Pocket: Rectangular, on the top face; Length 35, Width 6; Perpendicular 37.8 from the end and 10 from the side	the top face (Face6) selected + ribbon 'Home › Direct Sketch > Sketch', R key (tool True), first corner typed, opposite corner typed as length, width, MB2	differs	4 lines, corners as the book places the pocket; on the top face True. NX 12’s Pocket is a legacy feature (positioned with Perpendicular); NX 2212 cuts it with Extrude (Subtract) from a sketched rectangle, whose corners are typed from the pocket’s size and position
AT7	Depth 5.034, Taper Angle 14.5, OK	ribbon 'Home › Feature > Extrude (Subtract)', a side picked (QuickPick; Curve Rule Inferred Curves), dialog opened True; Boolean 'Subtract', 'lengthEdit' = 127.864 mm, 'taperEdit' = -14.5°; OK	same	same solid as the reference: 0 mm³ differ, box within 0 mm, 10 faces (10 in the reference); FreeCAD’s taper is negative for walls that close in with depth, as NX’s pocket’s do
AT8	Pattern Feature: the pocket, Linear, XC, Count 19, Pitch Distance 9.4, OK	the Extrude (Subtract) selected + ribbon 'Home › Pattern > Pattern Feature', {'axis': 'Base X-axis', 'mode': 'Spacing', 'count typed': 19, 'spacing': 9.4}, MB2 = OK	same	same solid as the reference: 0 mm³ differ, box within 0 mm, 82 faces (82 in the reference)
AT9	Cylinder along -XC at the end face’s centre (Between Two Points), Ø10 x 20, Subtract	ribbon 'Home › Feature', Type 'Axis, Diameter, and Height', Specify Vector '-XC', 'Between Two Points', MB1 near the end face’s corners (240, 0, 0) and (240, 25, 20) at pixels [(509, 381), (593, 187)]: Select Object (0) Between Two Points: 6096, 317.5, 254, Diameter 254 and Height 508 typed, Boolean 'Subtract', OK	same	same solid as the reference: 0 mm³ differ, box within 2e-12 mm, 84 faces (84 in the reference); origin (6096.0, 317.5, 254.0); one undo step ['Cylinder']; with Body
AT10	The rack	compared with the book’s dimensions built by the Part API	same	same solid as the reference: 0 mm³ differ, box within 2e-12 mm, 84 faces (84 in the reference)
AT11	Save and close the model	file name given once by script (the system file dialog is not driven); a change, then the Ctrl+S key	same	Arborpress_rack.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

AT1

Create a new file (Arborpress_rack)

Ctrl+N, Model template

same

new document ['Unnamed2']

AT2

Units in the New dialog (the book picks inches)

metric part kept; book sizes typed in mm

differs

FreeCAD sets units in Preferences, not in the New dialog; NXStyle defaults to millimetres (document: Standard (mm, kg, s, °); 25.4 mm shows as 25.40 mm)

AT3

Save it as Arborpress_rack

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

same

Arborpress_rack.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

AT4

Rectangle: corner 1 (0, 0, 0), corner 2 (240, 25, 0)

ribbon 'Home › Direct Sketch > Sketch' on 'XY-plane (Base plane)', R key (tool True), first corner typed, opposite corner typed as X, Y, MB2

differs

4 lines; corners all at the book. NX 12’s Insert > Curve > Rectangle is a curve outside sketches; NX-Style draws it in a sketch (NX 2212: Sketch > Rectangle)

AT5

Extrude the rectangle along ZC, Start 0, End 20

ribbon 'Home › Feature > Extrude', a side picked (click; Curve Rule Inferred Curves), dialog opened True; Boolean 'None', 'lengthEdit' = 508 mm; OK clicked

same

same solid as the reference: 0 mm³ differ, box within 0 mm, 6 faces (6 in the reference)

AT6

Pocket: Rectangular, on the top face; Length 35, Width 6; Perpendicular 37.8 from the end and 10 from the side

the top face (Face6) selected + ribbon 'Home › Direct Sketch > Sketch', R key (tool True), first corner typed, opposite corner typed as length, width, MB2

differs

4 lines, corners as the book places the pocket; on the top face True. NX 12’s Pocket is a legacy feature (positioned with Perpendicular); NX 2212 cuts it with Extrude (Subtract) from a sketched rectangle, whose corners are typed from the pocket’s size and position

AT7

Depth 5.034, Taper Angle 14.5, OK

ribbon 'Home › Feature > Extrude (Subtract)', a side picked (QuickPick; Curve Rule Inferred Curves), dialog opened True; Boolean 'Subtract', 'lengthEdit' = 127.864 mm, 'taperEdit' = -14.5°; OK

same

same solid as the reference: 0 mm³ differ, box within 0 mm, 10 faces (10 in the reference); FreeCAD’s taper is negative for walls that close in with depth, as NX’s pocket’s do

AT8

Pattern Feature: the pocket, Linear, XC, Count 19, Pitch Distance 9.4, OK

the Extrude (Subtract) selected + ribbon 'Home › Pattern > Pattern Feature', {'axis': 'Base X-axis', 'mode': 'Spacing', 'count typed': 19, 'spacing': 9.4}, MB2 = OK

same

same solid as the reference: 0 mm³ differ, box within 0 mm, 82 faces (82 in the reference)

AT9

Cylinder along -XC at the end face’s centre (Between Two Points), Ø10 x 20, Subtract

ribbon 'Home › Feature', Type 'Axis, Diameter, and Height', Specify Vector '-XC', 'Between Two Points', MB1 near the end face’s corners (240, 0, 0) and (240, 25, 20) at pixels [(509, 381), (593, 187)]: Select Object (0) Between Two Points: 6096, 317.5, 254, Diameter 254 and Height 508 typed, Boolean 'Subtract', OK

same

same solid as the reference: 0 mm³ differ, box within 2e-12 mm, 84 faces (84 in the reference); origin (6096.0, 317.5, 254.0); one undo step ['Cylinder']; with Body

AT10

The rack

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

same

same solid as the reference: 0 mm³ differ, box within 2e-12 mm, 84 faces (84 in the reference)

AT11

Save and close the model

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

same

Arborpress_rack.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.

The finished rack is compared with the book’s dimensions built by FreeCAD’s Part API.

What differs from NX

NX 12 draws the rectangle with Insert > Curve > Rectangle, a curve outside sketches. Here, as in NX 2212, it is drawn in a sketch.
NX 12’s Rectangular Pocket is a legacy feature, positioned with Perpendicular distances to two edges. NX 2212 cuts it with Extrude (Subtract) from a sketched rectangle; its corners come from the pocket’s size and position.
FreeCAD’s taper is negative for walls that close in with depth. NX’s pocket’s taper of 14.5° is −14.5° here.