ROCK TUMBLERS

There are two main kinds of rock tumblers: rotary and vibratory. Rock Tumbling machines are usually made up of a motorized base connected to a rotating drum or vibrating bowl. The motor spins or shakes the drum or bowl, causing stones to tumble inside the machine against each other within an abrasive slurry. Rotary tumbled stones are polished using a rotating barrel while vibratory tumbler stones are shaken in a bowl. Stones in both types of tumblers are processed in a sequence of different sized grits to grind and polish the rocks. You will want to purchase a tumbler with a capacity larger than the loads you need to process, keeping in mind that the tumbler will not be filled to the brim with your stones and some of the weight load will consist of water and abrasive grits. Check out each tumbler page, if manuals and instructions are available they will be downloadable at the bottom of the tumbler's product page.

• Rotary tumbling is the most common method, especially with beginners to tumbling. These tumblers create a smoother, more rounded rock by spinning the rock around an axis in a barrel. As a result, the edges are hit harder and more often than other areas which causes the rock to become rounded in shape with the corners and edges ground down to a smooth irregular curve. However, because the rock is rotated, it doesn't experience as many impacts as a vibratory tumblers and the process takes longer. Several rotary tumble models are available in multiple capacities ranging from large Diamond Pacific commercial rock tumblers handling up to 75 lbs of stone down to small Tumble-Bee home hobby tumblers processing 1-3 lbs of rocks at a time.
• Vibratory tumblers speed up the tumbling process by using vibration instead of gravity. This allows them to finish polishing faster than traditional tumblers. However, they aren't as effective at shaping or smoothing the surface of the rock. Because of this shaking motion, all sides and surfaces are worked almost equally which maintains the initial shape more predictably, this can be ideal for jewelers, carvers, and cabbers who have already pre-formed the shapes they want and are only looking to speed up the polishing process. Multiple vibe tumbler models are available for professional rock and metals processing, including Diamond Pacific's industrial-sized Viking Vibra-Sonic VT heavy-duty and VSV medium-duty series and smaller Mini-Sonic tumbler lines.

There are times when it can be advantageous to use both types of tumblers together to process a batch of rough stones. Rotary tumblers are used first because they will produce a perfect rounded shape by grinding off sharp edges and irregular corners. Vibrating tumblers are used for the sanding and polishing steps because they are much faster and do not need to change the shape of the rocks further after initial processing in the rotary tumbler.