Folding snap-button bag — trial patterns and 3D constructor

Folding snap-button bag: adjustable dimensions, separate pieces, holes, and PDF, SVG, DXF export. Trial construction for checking on a mockup.

Folding snap-button bag: construction example

Based on the original folding-bag principle, a custom layout was created for a 180 × 130 × 70 mm body. Front, bottom, back, flap, and overlapping side wings form one piece. Snap fastener holes Ø 3 mm, separate handle. First check snap alignment on a paper mockup; no stitching is needed for the body.

Open this example in the designer

The example opens with the dimensions specified below. Its changes are saved separately from your regular work. You can return to it using the link in the editor.

Example source parameters

Linear dimensions are given in millimeters. Parameter names match the designer fields; these are the initial settings and can be changed.

Parameter	Value
Body width	180
Body height	130
Body depth	70
Handle blank length	300
Handle width	20
Leather thickness	1.5
Stitch offset from edge	4
Additional seam allowance	0

Parts in this example

The dimensions below are derived from the geometric model. The parts list changes with the parameters and enabled options.

Piece	Size, mm
Body with flap and side wings · Spread	318.0 × 497.5
Short snap-button handle	300.0 × 20.0

How the size changes the pattern piece

Calculation example: the “body width” parameter was changed from 180 to 198 mm. The diagram shows the “Body with flap and side wings” piece · layout before and after recalculation at the same scale.

The dimensions below the drawing refer to the outer cut-edge contour. This is the result of a geometric calculation.

Open modified example

You can also download the modified JSON project. After modification, check the assembly on a mockup.

Download the pattern example

The files were generated using the standard VLOTHO CAD export from the parameters specified above. They show the model geometry and do not replace checking the product in the material.

PDF A4, 8 sheets PDF patterns, 1:1 SVG patterns, 1:1 DXF patterns, mm JSON project

PDF A4 automatically selects portrait or landscape pages and rotates the pieces to reduce the number of sheets. For assembly, a 10 mm overlap, numbers, and alignment marks are provided. The standard PDF contains one piece per page. Both variants include a 100 mm test segment. For your own dimensions, modify the project and export a new PDF. How to print patterns at 1:1 scale.

What to check before cutting

Calculated construction. Physical sewing has not been tested. First assemble a paper or inexpensive leather mock-up, then refine the fit and hardware.

VLOTHO CAD builds a geometric prototype. Allowances for bending, skiving, assembly thickness, and construction methods are determined by your material. Start with a paper mockup and a trial piece.

How to get a pattern for your dimensions

Open the model and set the dimensions in millimeters. To reproduce the tabular example, first load its JSON.
Check the parts list and enabled options. Adjust the seam and dimensions for your material.
Save the project and export a new pattern set. After changing the dimensions, the previous files no longer correspond to the project.

Dimension reference for this model: Stitching line. Dimensions in the parts table and the outer cut contour may differ due to the seam allowance. How to check seam allowances and stitching lines.

Materials and assembly

Select the leather according to the required stiffness and assembly method. The image was generated and shows the intended appearance.

File preparation

Printing patterns on A4 at 1:1 scale · DXF units and layers before cutting

Next step

Construction and export instructions · Manual contour editing · All models