The terms used on this site, defined as they apply to a precision diamond wire saw. Where a figure is given, it is the published figure for the Gem Slicer Standard and the Gem Slicer Mini.
Anti-Tummy
Anti-tummy is a Gem Slicer software function that pauses the Z feed at intervals while the wire keeps running. The wire goes on cutting where it already is, catches up with the material it left behind in the middle of a long cut, and the slice comes out flat instead of convex. The default is 15 minutes of pause per hour, adjustable to the material. See the software.
Automatic Cutting
Automatic cutting is a queue of slices that the Gem Slicer works through on its own. For each group of slices you set the cutting parameters and the pauses, and a recipe that works can be saved and loaded again for the next specimen of the same material. It is what makes an overnight run practical. See the software.
Closed Water Loop
A closed water loop recirculates the cutting water from a reservoir inside the machine instead of taking it from a tap and draining it away. A Gem Slicer needs no water supply and no drain where it is installed. The Standard also monitors the water level; see unattended cutting.
Cutting Farm
A cutting farm is a group of diamond wire saws running side by side under one operator. A wire saw cuts more slowly than a blade but runs around the clock, so capacity is usually added by adding machines rather than by cutting faster. See custom solutions and cutting farms.
Cutting Feed (Z)
Cutting feed is the rate at which the specimen and the wire move into each other along the Z axis, set in millimetres per hour. On the Gem Slicer it is adjustable from 1 to 200 mm/h. Hard and large specimens need a slower feed.
Diamond Wire Saw
A diamond wire saw cuts with a thin steel wire that carries diamond abrasive. Two very different machines share the name. Precision diamond wire saws use wire a fraction of a millimetre thick to slice specimens in laboratories and workshops; beaded-rope wire saws cut blocks in quarries and reinforced concrete in demolition. The Gem Slicer is a precision diamond wire saw. See our diamond wire saws.
Endless Wire
Endless wire is diamond wire joined into a loop that travels in one direction only. It is also called closed-loop or one-way wire. Both Gem Slicer models have been built to accept it since the first model: the loop is 1.6 m on the Standard and 1 m on the Mini, and the changeover takes about five minutes with an adapter that is in preparation. Closed-loop wire is 0.6 mm thick, so the kerf is 0.6 mm rather than 0.22 mm.
FCA Sofia
FCA (Free Carrier) is the Incoterms rule under which Gem Slicer prices are quoted. We pack the machine, clear it for export and hand it to the carrier in Sofia. Transport and insurance appear as separate lines on the pro forma invoice, or you can arrange your own carrier; import duties are paid by the buyer.
Hour Meter
The hour meter counts the running time of the Z axis and shows it on the machine screen. Gem Slicer maintenance is scheduled in operating hours rather than calendar time: the roller bearings are checked at 3,000 hours, which a machine cutting around the clock reaches in about four months. See Gem Slicer Standard.
Kerf
Kerf is the width of material a cut removes. With the 0.22 mm wire supplied with the Gem Slicer, the kerf is 0.22 mm; a conventional diamond blade removes 1.5–3 mm. On a 40 mm stone cut into 2 mm slices, that is the difference between 8 slices and 18.
Kerf Compensation
Kerf compensation adds the wire diameter to every X move, so the slice thickness you enter is the thickness you get. The real cut is slightly wider than the bare wire, so the setting is calibrated by measuring one slice and entering the measured figure. The offset is systematic and calibrates out.
Minimum Slice Thickness
Minimum slice thickness is the thinnest slice a saw produces reliably. For the Gem Slicer we publish 0.25–0.3 mm, verified repeatedly in brittle stone meteorite. Thinner slices are possible (we have measured 0.191 mm), but below about a quarter of a millimetre not every slice survives. See Gem Slicer Mini.
Positioning Laser
The positioning laser projects the cutting plane onto the specimen before the cut starts. The operator sees where the wire will pass and can align a specimen to the same plane again later. It is a positioning aid, not a marking laser. Both Gem Slicer models have one.
Positioning Resolution
Positioning resolution is the smallest step an axis can make. On the Gem Slicer X axis it is 0.02 mm, driven by a ball screw. It is not the accuracy of the slice: the wire deflects during the cut, so slice tolerance is stated separately.
Reciprocating Wire
Reciprocating wire is diamond wire wound on a spool that runs back and forth between two reversing points. It is also called spool, open-loop or two-way wire. It is the Gem Slicer standard mode, with 0.22 mm wire supplied. The spool holds 80 m on the Standard and 30 m on the Mini, and both models accept wire from 0.1 to 0.8 mm.
Reversing Sensors
Reversing sensors tell the reel when to change direction. On the Gem Slicer they slide along a rail, and their position sets the working length of wire, from about 5 m up to a full spool. A wire that breaks by jamming in the cut can be shortened and used on.
Slice Tolerance
Slice tolerance is how far a slice may deviate from the thickness that was set. The Gem Slicer holds ±0.05 mm at 2 mm slice thickness. Three slices set at 2.00 mm and measured with a micrometer came out at 1.951, 1.970 and 1.979 mm.
Unattended Cutting
Unattended cutting means running a cut or a series of cuts with no operator at the machine. On the Gem Slicer it combines automatic cutting, the built-in camera and remote access. The Standard also has two water level sensors: the first warns on screen, the second stops the cut. The Mini has no level sensors, so its water is checked by the operator.
Wire Bow
Wire bow is the curve a diamond wire takes under feed pressure, lagging behind in the middle of the cut. On a pallasite slice cut with 0.22 mm wire we estimated the bow at roughly 1.5 mm. Anti-tummy and Z-retract exist to keep it under control. See Wire Bow: Why a Diamond Wire Never Cuts Perfectly Straight.
Wire Linear Speed
Wire linear speed is how fast the wire travels, in metres per minute. It is adjustable from 40 to 120 m/min on the Gem Slicer Standard and from 40 to 100 m/min on the Gem Slicer Mini.
Z-Retract
Z-retract is a companion function to anti-tummy that lowers the Z axis on a pattern the operator sets, straightening the bow the wire has taken. It earns its place on very hard or very large material, where the right feed rate cannot be judged in advance. See the software.