VLOTHO / CAD

Roll-top backpack — configurator and trial patterns

Test · tall tube · two shoulder straps · Dimensions, 3D model, and PDF A4, SVG, DXF patterns at 1:1 scale.

Body 270 × 330 × 110 mm, 160 mm roll-top extension. Front, back, two side panels, bottom, two shoulder straps, top loop and fastening strap. The 3D view shows one notional turn of the top section; the usable capacity height depends on the number of turns. Independent trial construction based on the shape principle, not a copy of a commercial pattern.

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.

Parts in this example

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

How the size changes the pattern piece

Calculation example: the “body width” parameter was changed from 270 to 297 mm. The diagram shows the “Panel with roll-top” piece before and after recalculation at the same scale.

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, 26 sheetsPDF patterns, 1:1SVG patterns, 1:1DXF patterns, mmJSON 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

The dimensions are preliminary. First assemble a paper mockup, then make a trial piece from inexpensive material. Not verified by sewing.

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

1. Open the model and set the dimensions in millimeters. To reproduce the tabular example, first load its JSON.
2. Check the parts list and enabled options. Adjust the seam and dimensions for your material.
3. 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 thickness and stiffness, seam allowances, and hardware on a mock-up. Image — a generated illustration of the construction.

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