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REFERENCE · 5 MIN READ

Types of faceting machines.

A taxonomy of bench faceting machines by mast rigidity, angle readout, and stated runout class.

Contents · general reference
01Overview of lapidary equipment categories8 MIN02What is a faceting machine?4 MIN03Types of faceting machines5 MIN04Types of laps used in gem cutting6 MIN05Understanding lap grits and progressions6 MIN06Introduction to dops and transfer systems5 MIN07Overview of common rough gemstone materials8 MIN08Gemstone hardness and cutting difficulty overview5 MIN09Polishing compounds overview5 MIN10Measurement instruments in lapidary and gemmology5 MIN
Contents · gemstone overviews
G01Corundum rough overview5 MING02Quartz rough overview5 MING03Beryl rough overview5 MING04Garnet rough overview5 MING05Tourmaline rough overview5 MING06Topaz rough overview5 MING07Peridot rough overview4 MING08Spinel rough overview4 MING09Chrysoberyl rough overview4 MING10Zircon rough overview4 MIN
About this entry

This reference entry describes categories of equipment and material encountered in the lapidary trade. Definitions, typical specifications, and usage ranges are drawn from published manufacturer documentation and standard glossaries. It does not constitute instruction, training, or professional advice. Readers interested in acquiring equipment should consult a qualified retailer or craftsperson.

Where a manufacturer or product name appears in the text, it is illustrative. Links to retailer listings elsewhere on the site are affiliate links and are disclosed as such.

Classification axes

Bench faceting machines in current production are classified along four principal axes: mast rigidity, angle readout, stated spindle runout, and overall build class.

Mast rigidity

Mast assemblies fall into two broad categories. Rigid masts use a single machined column anchored at the base, with the quill traveling on close-tolerance bearings. Rigid masts are standard in the mid-range and above and are characteristic of the Ultra Tec, Facetron, Polymetric, and Imahashi machines. Flexible masts — sometimes called jointed-arm machines — use a multi-segment arm that pivots at one or more points; they are simpler and less expensive but allow more deflection under cutting load. The Mirage and entry-tier Hi-Tech machines are representative of the flexible-mast tier.

Angle readout

The angle-setting mechanism is either analog or digital. Analog mechanisms use a detent or vernier scale on a mechanical sector arm; the cutter reads the angle directly off a graduated scale. Digital mechanisms use a rotary encoder coupled to a numeric display, with resolutions ranging from 0.1° on entry-level units to 0.001° on the highest-precision machines. Digital readouts simplify cheater adjustments and meet-point work; analog mechanisms are mechanically simpler and have no electronics to service.

Stated spindle runout

Manufacturers publish a stated total indicated runout (TIR) figure for the spindle assembly. Values cluster as follows:

  • 0.0003"–0.0005" — connoisseur class (Polymetric Scintillator, Ultra Tec V5)
  • 0.0006"–0.0008" — mid-range (Ultra Tec V2, Facetron, Imahashi)
  • 0.0010"–0.0015" — entry tier (Mirage, Graves, Hi-Tech)

TIR is published by the manufacturer; field measurement requires a precision indicator and an arbor.

Build class and provenance

Build class is a soft category that aggregates fit and finish, spindle bearings, motor type and speed control, mast finish, base mass, and accessory ecosystem. North American boutique production (Ultra Tec, Facetron, Polymetric) is at the top of the class hierarchy; Australian production (Gemmasta) and Japanese imports (Imahashi) sit alongside; mass-production lines (Mirage, Hi-Tech) occupy the entry-to-mid tier.

Accessory ecosystems

Index wheels, cheater attachments, dop kits, master laps, and quill-related fittings are partially interchangeable. The 1/2-inch dop shaft is the de facto standard across all major North American machines; index wheels in 64-, 80-, 96-, and 120-tooth configurations are available from most manufacturers. Where compatibility is documented, it is typically published in the manufacturer's accessory catalog.

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