Gold Rat Metal Detectors is located 6/50 Freda Street Upper Mount Gravatt. This is the only store to stock Metal Detectors. Gold Rat Engineering is located 4/16 Redcliffe Gardens Drive Clontarf This is where you will see the largest range of your highbankers, sluices and accessories

We are no longer stocking this product please see armstrong industries for any inquiries


Manufactured in Western Australia by Armstrong Industries.  please contact Armstrong for stock availability.

The Ultimate in Mobile Rock Crushing capabilities the GRB (Gold Rock Breaker) 777XL has been customer Designed and manufactured by Armstrong Industries in Australia.

This father and son business brings 40 years combined mining experience to the table. The 777XL rock crusher plant has taken a several years to perfect, with countless hours in production and in the field testing in Western Australia.

The GRB 777XL is built for the serious prospector and small scale miner. It is capable of crushing approximately 500kg of rock per hour.

The Impactor bars are made from special High Grade Carbon Steel with a rating of 67 HRC. Offering you the long life and great wearing capabilities you would expect from any over engineered Aussie build plant.

777XL Rock Crusher Options

Bottom Screens available the standard size is 1.2mm So you can alter the output size of your crushed material. additionally the slots on the Bottom Screen are slightly tapered from inside to outside thus reducing clog ups and downtime.

Our screens are locked in place with heavy duty quick release clips making removal and install a piece of cake, this is apparent when you run your pump dry out of fuel and need to clear the load.

Armstrong Industries are serious about safety and No Shortcuts are taken. They offer many safety features included in the design to protect the operator including the design of the feed hopper and the gravity flap to eliminate rocks kicking out the top of the unit.

The steel frame has four flat free tyres and a neat turntable steering setup.

All Replacement components are readily available.


LENGTH- 1100mm

WIDTH- 600mm

HEIGHT- 1250mm

WEIGHT- 140kg

ENGINE- Petrol Electric Start 15HP

FEED HOPPER OPENING- 150mm x 100mm

CAPACITY- 500kg per hour Approx.