COBORN MOTOR

Throughout the world, Coborn skive equipment is known as the "Rolls Royce" of skives. Many of the worlds most famous and valuable gemstones have been polished on Coborn equipment.
 

Coborn skives spindles are precision instruments for running diamond loaded skive plates at high speed.

Air Flow extraction spindles

1 HP variable height Type SK-KBS.
2 HP variable height Type SK-FBS.

These spindles have a self powered air evacuation system, giving distinct heath & cleanliness advantages. The outward air can be passed through either a static filter box (available from Coborn), or to a centralized trunking system.

Flange type spindles 1 HP fixed height Type SK-K , 1 HP variable height Type SK-KS. 2 HP fixed height Type SK-F , 2 HP variable height Type SK-FS.

With thousands of units throughout the world the reputation of our skive spindles is second to none.  Every Coborn spindle benefits from over fifty years experience of supplying all types of spindles to the machine tool industry.  We believe, as do many of our customers, that Coborn spindles are of the highest quality commercially available worldwide.

All Coborn skive spindles can be supplied with:

1. The expanding nose system; this locates the plate on the true axis of it's bore, resulting in minimal unbalance vibration. A secondary benefit of this system is that 'on loosening' the nose diameter reduces to 0.015mm undersize, allowing easy removal.
2. The balance correction cap (either fixed or dynamic), which allows the very last vestiges of unbalance to be removed. This is when used with,
3. Our portable balancer PB1 (see balancing section). If your skives are not to the ultimate balance correction accuracy, or are not balanced using expanding mandrels (i.e. skive is not precisely located), then this process will eliminate that tiny residual error. For 'triple excellent', a distinct advantage.

Standard benches
All benches are "Open Top". They have a 23mm thick heavy steel table top covered with formica (stainless steel is an option). All the electric's are supplied in an enclosure. All Coborn skives can be supplied with variable speed with the aid of an inverter, speeds would normally range from 2,000 to 4,000 revs/min.
Bench can be supplied with a variety of ancillary equipment, e.g. guarding, armrests, tang racks, spare skive storage, lifter signals.

Planetary benches
Same specification as the standard bench, but in addition, the spindle moves in a slow, horizontal planetary motion.  The speed of the planetary motion is continuously variable, and it is possible to select any one of 24 different locii, from 1.4mm to 32mm.

1 HP adjustable stroke, adjustable height Type PS1-BS
2 HP adjustable stroke, adjustable height Type PS2-BS

Planetary benches, normally used for industrial mono crystalline, are sometimes of interest in the gem field. Particularly for research institutions, but also for cutting difficult stones, where the small change of angular approach helps with grain, and the planetary motion helps reduce skive plate tracking.