Sheet 05 of 15

Flanges on Several Edges: Corners, Gap and Corner Reliefs

Q: Why pick all four edges in the same Flange?

Only flanges of one feature have their corners closed toward each other. The corners are closed, with the rule's gap, only between flanges of one feature.

Q: Where does the gap between two walls at a corner come from?

The Flange Gap in the sheet metal rule. Flange Gap is a rule value; by default it equals the thickness.

Q: You switch the corner relief from Notch to Round. What changes?

A round cut at each corner, and shorter bends. The round relief is cut out of the corner and the bends stop where it begins; the flat size stays the same.

In 6 minutes you'll fold up all four walls of a tray in one Flange, see how SolidCraft closes the corners with a gap, and choose a corner relief shape.

Part: Corners and Reliefs
Rule: Steel 2mm
Sheet: t 2 · R 2 · K 0.4
Time: 6 min
Status: Open

OP 10Watch
OP 20Turn the part
OP 30Build
OP 40Inspect
OP 50Quiz

OP 10Watch

Video in productionBuild along with the steps in OP 30 meanwhile.

OP 20Turn the part

Drag to turn, scroll or pinch to zoom. Flat shows the blank before it is bent: the same sheet, the same frame.

OP 30Build it in SolidCraft

Your task

Build this tray from the drawing above.

The rule from the drawing's notes (leave its corner values as they come), then the base as in lessons 1 to 3.
Flange on all four top edges in one go, the long front edge first: the height from the drawing, angle 90°, Bend Position Inside.
Flat Pattern: read both numbers of the Flat size.
New this time, the bend table: in the Flat Pattern press Export Bend Table…, save the CSV, open it and read length_mm of bend 1.
Edit the flange: under Advanced, Corner Relief Shape Round, Corner Relief empty. Read bend 1's length again.
Give the tray the Physical Material Aluminum and read its Mass in Properties; then Steel, and read it again.

What to write down

Boxes 1 and 2: Both numbers of the flat size (they don't change with the relief shape).
Box 3: Bend 1's length with the Notch corner (the rule's default).
Box 4: Bend 1's length with the Round corner relief.
Boxes 5 and 6: The tray's mass in aluminum and in steel, in grams (the Round relief tray; type the number only).

Bend 1 is the first edge you picked. Type the values below and press Check. The bend table opens in any spreadsheet app or text editor.

OP 40Inspect

SolidCraft's Flat Pattern with Export Bend Table circled, and the exported bend table with its length_mm column marked, bend 1's row first — Where to read a bend's length: 1. In the Flat Pattern, Export Bend Table… and open the file. 2. The length_mm column; bend 1 is the first edge you picked.

Enter what SolidCraft shows you. Each value is checked against SolidCraft's own result, within the tolerance shown. Nothing you type leaves this page.

Box 1Flat size, first number ± 0.05 mm mm

Box 2Flat size, second number ± 0.05 mm mm

Box 3Bend 1 length with the Notch corner relief (length_mm in the bend table) ± 0.05 mm mm

Box 4Bend 1 length with the Round corner relief ± 0.05 mm mm

Box 5Tray mass in Aluminum (Round corner relief) ± 0.5 g g

Box 6Tray mass in Steel (Round corner relief) ± 0.5 g g

Stuck? Compare with the finished part

Download the finished part

Open it in SolidCraft (File › Open) next to yours and compare the timeline, the rule and each feature's sizes: the first one that differs is where yours went wrong.

exercise · Steel 2mm · t 2 · R 2 · K 0.4 · all dimensions in mm, from the blank's left and bottom edges

Flat blank 162.797 × 122.796 mm · 4 bends

Bend	Angle	Dir.	R mm	Length mm	Allowance mm
1	90°	up	2	112	4.398
2	90°	up	2	72	4.398
3	90°	up	2	112	4.398
4	90°	up	2	72	4.398

exercise-round · Steel 2mm · t 2 · R 2 · K 0.4 · all dimensions in mm, from the blank's left and bottom edges

Flat blank 162.797 × 122.796 mm · 4 bends

Bend	Angle	Dir.	R mm	Length mm	Allowance mm
1	90°	up	2	104	4.398
2	90°	up	2	64	4.398
3	90°	up	2	104	4.398
4	90°	up	2	64	4.398

exercise-steel · Steel 2mm · t 2 · R 2 · K 0.4 · all dimensions in mm, from the blank's left and bottom edges

Flat blank 162.797 × 122.796 mm · 4 bends

Bend	Angle	Dir.	R mm	Length mm	Allowance mm
1	90°	up	2	104	4.398
2	90°	up	2	64	4.398
3	90°	up	2	104	4.398
4	90°	up	2	64	4.398

OP 50Quiz

Q1Why pick all four edges in the same Flange?

Q2Where does the gap between two walls at a corner come from?

Q3You switch the corner relief from Notch to Round. What changes?