Circle Templates 4/6/8/10 in, Quilting & Applique

Draw round it, cut it out. Four exact circles, 4, 6, 8 and 10 inch, ready to print.

Files

• STL: ring_4in.stl, ring_6in.stl, ring_8in.stl, ring_10in.stl. Plain mesh, any slicer.

• 3MF: circle_ring_4in.3mf, circle_ring_6in.3mf, circle_ring_8in.3mf, circle_ring_10in.3mf. Bambu Studio project with my tested settings (PrusaSlicer opens the geometry).

• SCAD: solid_circle_template.scad. The parametric source, for any other size.

Which size do I print?

Each ring has its own STL and 3MF, so pick your size and print it.

• 4 in: 101.6 mm; 22 g; all, including the A1 mini

• 6 in: 152.4 mm; 37 g; all, including the A1 mini

• 8 in: 203.2 mm; 51 g; needs a 256 mm bed

• 10 in: 254 mm; 66 g; needs a 256 mm bed

Need a different size? The .scad file does any diameter in inches, centimetres or millimetres, solid or ring.

What it is for

Quilting and applique first, which is where it came from. Lay it on the fabric, draw round it, cut along the line. There is no seam allowance in it and no offset applied, so the outer edge is exactly the circle you get.

Plenty of other things want an accurate circle though:

• circles on card for card making and scrapbooking

• a stencil for paint, ink or spray on paper, wood or fabric

• marking out a hole before cutting it in plywood, plasterboard or acrylic

• pattern making for leather, felt and craft foam

• printed hollow at a large size it is a hoop or a wreath base in its own right

• a classroom set of exact circles, which is cheaper to print than to buy

Customise in OpenSCAD

Download the .scad file and open it in OpenSCAD (free). Every option below is in its Customizer panel.

• Diameter: The circle it draws. The outer edge is the line, with no offset or fudge factor

• Units: Inches, centimetres or millimetres. Every other measurement follows your choice

• Thickness: 1/4 in (6.35 mm) by default, matching shop-bought templates

• Ring mode: Hollows the middle and leaves a band: far less filament, same drawing edge

• Ring width: How much material sits behind the edge. Default 1 in, or 2.5 for cm, 25 for mm

• Link hole: A small hole near the edge, so a set threads onto a keyring or carabiner

• Embossed label: The size on the top face, worked out from the diameter and unit. Turn it off, resize it, or type your own

Why it is shaped the way it is

The bottom edge is square and vertical and the chamfer is on the top face only. If the underside is rounded, a pen tip creeps beneath the edge and you draw inside the true line, so every circle comes out slightly small.

Nothing is embossed on the underside either. Anything standing proud down there would make the template rock and the drawn line wander.

It refuses bad settings rather than printing them: a ring wider than the circle's radius, or a label too big for the band, stops with a message.

Pairs with

• Crescent Templates: long, gentle arcs for borders and swags

• Concave Curve Template: two inward arcs for curved piecing and quilting lines

• Quarter Circle Template: drunkard's path and quarter-circle blocks

All of them are in my Quilting & Sewing Tools collection.

Print settings

• Material: PLA, or PETG if it will get knocked about

• Layers: 0.2 mm, or 0.12 mm for the smoothest drawing edge

• Walls: 4 to 5, because the edge is the functional surface

• Infill: 15% gyroid. The walls make the edge, so more infill only adds weight

• Supports: None, flat on the plate as oriented. Do not stand it on edge

• Elephant foot compensation: 0, and no first-layer chamfer

• Wall order and seam: Outer wall first and a scarf seam, so the drawing edge stays clean and true. The 3MF here already has both

The embossed label stands 0.8 mm proud, so a 6.35 mm body measures 7.15 mm overall. The 10 in ring is 254 mm across, right at the limit of a 256 mm bed, and a circle cannot be rotated to help.

The parameter design and the testing here are mine. The OpenSCAD was written with Claude, and every version was rendered and measured before it went up.

If it is useful, a like and a make with a photo really help. I read every comment.

Also on MakerWorld: https://makerworld.com/en/models/3257812