This is a standard application used by a borer company and is machined from Vesconite bushing with an outside
diameter 300 x 250 - 1000 mm (11.8" x 10" - 39.4") standard stock. The boring machine is used to bore out
chutes from one level to the other. This particular machine bores a 1½ metre hole at angles varying from the
vertical to a 30o incline. Chutes up to 120 m long can be bored.
The hole is drilled at a rate of 1.5 metres (5') per hour. All the rock, chips and debris that result form the cutting
action fall down the hole along the length of the drill steels and contaminate the bearing surfaces.
Stabilizers to align the drill steel and prevent whip are placed every 5 metres (16') along the length of the drill
pipe. Each stabiliser is lined with a Vesconite bush. The drill rotates at 16 rpm within the Vesconite bushing.
Spring loaded lip seals are used to provide some protection from rock chips, abrasive debris and run of mine
There are 20 stabilizer rods per machine, each rod being approximately 1 m (3.3') long. On the upward drill every
fifth rod is a stabilizer rod. The use of Vesconite allowed greasing to be reduced to overhauls only. Vesconite has
a 12 - 15 month life in this application. No other material worked successfully in this application.