Portable Rock Crusher - Gold Mining Equipment Portable rock crusher - great for sampling gold bearing and other rocks in the field! Portable -- weighs only about 10 pounds. 1 year manufacturer's warranty. Grinding chamber: 7.5 inches x 3.5" wide x 9" tall including feed tube. This latest model of the Cobra Crusher has a straight feed tube. This makes it easier to feed rocks into it and much easier to pour out the pulverized material. All steel construction with chain hammers. Cobra portable rock crusher will quickly grind your samples down to powder!