Square-to-Round Flat-Pattern Generator

Square / rectangular / offset-to-round — triangulation development · DXF + full-scale PDF

Develop the flat pattern for a square-, rectangular-, or offset-to-round transition. Enter the base, the round, the height, and any offset; get a cuttable pattern with fold lines. Exports DXF for the cutter and a tiled full-scale PDF for the bench. Sibling to the Cone / Transition generator.

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How to use: Enter base width × depth, round diameter, height, and any offset. Review the flat pattern and plan view, then export DXF for the cutter or a tiled full-scale PDF for the bench. Print at 100% / Actual Size, measure the reference square, join the orange seam edges, and add your own lock / flange allowance. See the guide and troubleshooting.

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Cut the developed pattern, then form and join — products from the TestTalkHQ affiliate catalog

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Catalog gaps: No hand seamer / seamers, rivet gun, or sheet-metal brake products exist in the TestTalkHQ affiliate CSV at publish time — we do not substitute unrelated electrical or welding gear for those roles.

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Triangulation Flat Patterns for Square-to-Round

This generator develops square, rectangular, and offset-to-round transitions by triangulation — true-length elements from the base to the round, unfolded by sequential circle intersection. Export DXF for the cutter and a tiled full-scale PDF for the bench. Print at 100% / Actual Size and verify the reference square before cutting. See the guide for the method and SVG legend.

Sibling to Cone / Transition Developments

Round-to-round cones, frustum reducers, and lobster-back elbows belong in the Cone / Transition Flat-Pattern Generator. Use both when a job runs square plenum → round trunk → elbow. Decision guide: Square-to-Round vs Cone — Which to Use.

Nest and Price the Blank

After you have a pattern, nest it with the 2D Sheet Nesting Optimizer and estimate cut time with the Cut-Cost & Time Estimator. Seam / lock stock is still yours — seam allowance by joining method.

Square-to-Round Flat-Pattern Generator