SnipFold

Faceted Hot-Air Balloon

Eight four-facet gore nets form an octagonal balloon with a narrow open neck, reinforced crown and four paper suspension straps carrying an open basket. Decorative, nonfunctional.

Materials

  • 160-180 gsm cardstock: G1-G8, C, R, B1-B4, F and S1-S4 (19 individual paper pieces)
  • One 400 mm length of 0.5-1 mm cotton thread for the crown hanging loop (not a paper template part)
  • PVA glue; scissors; scoring tool; ruler; craft knife and cutting mat for two 2 mm holes
  • Temporary assembly supports: two equal 50 mm-high blocks; remove after drying; a hanging hook or stand

Finished size: 100 mm maximum vertex diameter x 195 mm paper height; basket 29.56 x 29.56 x 20 mm; hanging loop approximately 170 mm above crown

Steps

CutValley foldMountain foldGlue area

  1. Print, cut and score

    Print at 100 percent; measure the 50 mm ruler. Cut all 19 paper pieces, preserving every integral flap. Cut the two 2 x 2 mm holes in C and R. Score printed folds. Gores run from the narrow open bottom to the narrow crown; glue markings face inside.

  2. Crease the faceted gores

    From the outside printed face, mountain-fold each gore at the three horizontal joins: turn approximately 19.6, 26.8 and 36.6 degrees respectively, bottom to top. Leave each trapezoid flat. Fold each 4 mm right-side flap inward to meet the adjacent gore, and the 5 mm crown flap inward. Match edges rather than rounding or stretching the paper.

  3. Join eight gores

    Arrange G1 through G8 counterclockwise viewed from above. Glue each G right-edge flap beneath the next G left cut edge, with a 4 mm overlap; align all four facet endpoints exactly. Join G8 to G1 last, pressing seams through the still-open crown and neck. Work in pairs, let each seam set before closing. Ring vertex diameters bottom to top are 32, 80, 100, 84, 32 mm; height is 125 mm.

  4. Reinforce and thread the crown

    Glue R centrally under C, matching the two holes 12 mm apart; keep holes clear and dry flat. Cut exactly one 400 mm cotton thread. Feed one end up through each hole so a 12 mm bridge remains beneath R. Tie the two free ends together above C with a double knot using about 40 mm total for knot and tails; the resulting loop rises about 170 mm. Thread is not shown in the preview.

  5. Close crown

    Dry-fit C with its eight edges aligned to the eight gore tops. Glue it onto all eight inward 5 mm crown flaps, holes across the center. Press through the open neck with a blunt tool and let dry completely before applying tension to the loop.

  6. Make the open basket

    Fold each B side flap and bottom flap inward 90 degrees. Join B1-B4 cyclically, each right 5 mm flap behind the next wall. The outside square is 29.56 mm across, height 20 mm. Glue F over the inward bottom flaps, keeping walls square. Press from the open top and dry.

  7. Attach four suspension straps

    Glue the lower marked 8 mm of S1-S4 onto the centered outside faces of B1-B4, from 12 to 20 mm above the floor. Each strap is 6 x 66 mm. Crease at 58 mm from its lower end about 32.4 degrees outward so the upper 8 mm follows the balloon lower facet. S1-S4 attach to G1,G3,G5,G7 respectively at the center of each neck edge, with 8 mm measured up the sloping face.

  8. Set spacing and hang only when dry

    Support the shell using the hanging loop at a height where its neck is exactly 70 mm above the basket floor: the open gap above the 20 mm basket rim is 50 mm. Use two temporary equal 50 mm blocks between rim and neck while gluing upper strap overlaps; do not glue blocks. Keep all four straps straight and the basket level. Dry fully, remove blocks, then gently test hanging over a soft surface. Adjust thread on its hook to level. No payload; print, seam fit and hanging strength still require physical verification.

Notes

The 3D model shows each piece in its finished, idealized shape; the exploded view only spreads the pieces apart. It is not a paper-physics simulation: curved shapes are forming guides, not exact physical folding or proof of developability, and intermediate fold shapes are not supplied.