The Kitiki Rotary Tumbler Kit 3 is a studio tumbler, and can be used for stones, minerals, glass, and shells. The drum is 36% larger than the one in Kit 1 and can hold twice as much shot.

It consists of a motor base, a 950gm rubber drum, 1000gms of mixed stainless steel shot and burnishing shapes, and 500gms of barrelling compound to keep the drum clean. It's robustly made, easy to use, quiet when running, and, best of all, does its work whilst you do something else.

The whole unit measures 195mm x 105mm x 200mm. The CE-marked fully-enclosed motor is rated at 230V 15W, so you can use a regular mains socket. It comes with a 1.8 metre cable, ending in a UK plug. Since the tumbler uses about as much power as a fridge bulb, the cost of using it is only a few pence a day.

The rubber barrel revolves quietly; the drum lid has a leak-proof easy-to-fit lid with a seal and a retaining collar; the tumbler has rubber feet to stop it creeping across the worktop; and the rubber rollers and rollerball end-stops keep the drum in the correct position. The drive belt is toothed and nylon reinforced, so it won't slip or wear out quickly.

As you can see in the photo, a 950gm drum uses the full width of the tumbler body, although you could use two smaller drums if some work needs a long tumbling time and other pieces just need a quick freshening up. The 950gm is often called a full-size or 3lb drum, and the 510gm a half-size or 1.5lb drum.

Although the component parts of the kits can be bought separately, it's more economic to buy the whole kit. Also, if you just buy the tumbler body, high street stores won't have stainless steel shot or barelling compound.

The tumbler will accept one 950gm barrel or two half-size barrels, so that you can leave one on for a long time but use the other with different abrasives or for shorter periods. The full-zize 950gm barrel is 135mm x 115mm diameter, and the half-size 510gm barrel is 75mm x 115mm diameter.

If you want to use two half-size barrels at the same time, they sit on the tumbler body with both lids facing outwards. Don't get them muddled if you stop the tumbler to check for progress. Many people prefer to use a separate drum for the final polish in case stray particles of grit scratch the finished surface. Put coloured dots on them?

The drum lids have several parts: at one end there's an inner metal lid, a rubber sealing ring, a metal outer lid, and a retaining threaded collar. To prevent any leaks, make sure that they're kept clean and are re-fitted carefully.

The stainless steel shot, included in some of the rotary tumbler kits, is not just round but a selection of shapes, such as pins, planetoids, and spheres, designed to deal with the range of contours on jewellery.

Although the shot is 100% stainless steel, don't leave it lying around wet: either leave it immersed in the tumbler mix of water and cleaner, or rinse it and dry it carefully.

If you need to replace the shot, don't economise and buy plain or mixed steel: unless you're meticulous about cleaning and drying them every time you use them, they will soon rust, make a mess, and ruin your work.

When you open a new packet, always do it over a bowl. The shot is surpringly agile and will easily escape, go on the floor, and roll everywhere. If you do spill it, brush it up, or use a magnet: then wash it.

When you've finished, empty the shot into a cloth-lined sieve, rinse it thoroughly, and spread it on some cloth to dry. Don't accidentally flush away any shot as it will collect in the basin trap and lead to a blockage.

Grit is the generic name for particles used to polish and grind. The grit that comes in The Kitiki Tumbler Kit 3 is silicon carbide: a hard, sharp, angular material. In use, it fractures into smaller angular particles, so is a very effective abrasive. Grit sizes are rather confusing: for example 400 grit particles are not half the size of 200 grit particles. You learn, through use, which grit to use for different materials, shapes, and finishes.

Grit should be handled and stored carefully to prevent contamination from stray larger particles that will scratch. Keep the tubs sealed until you need to use them. In use, transfer a small amount into a working container, to minimize the risk of contaminating the whole tub. And wash the drums thoroughly before and after use.

When you've finished, empty the grit into a cloth-lined sieve, rinse it thoroughly, and spread it on some cloth to dry. Be careful not to flush away any grit as it may collect in the basin trap.

Barrelling compound, sometimes called gallay compound, is a special soap used to keep the barrel and shot clean, lubricate the tumbling, help the polishing action, and minimise rust. The fdull-size drum needs about a level tablespoonful.

Cerium belongs to the group of elements known as the rare earth elements. To produce the polishing powder, about 80% of cerium oxide and 20% of other rare earths are used, resulting in a pink-ish powder.

As polishing is the final step in the surfacing process, don't expect to remove marks or scratches made during previous steps shaping or finishing.

The tumbler comes with a 2.0 metre cable, ending in a regular UK 230V plug. As the motor is only 15W, you can use any mains socket. The plug only needs a 3A fuse and must be earthed.

Since the tumbler uses about as much power as a fridge bulb, the cost of letting it run continuously is only a few pence a day.

As with all electrical equipment, don't get it wet and don't touch it with wet hands. Always unplug it when it's not in use or being serviced.

Always empty the drum away from the tumbler, to avoid spilling or losing anything. Every two weeks, unplug the tumbler and put a few drops of oil on any visible bearings. Leave the belt as loose as possible without it slipping.

The tumbler has rubber feet to stop it creeping. However, make sure it's on a stable flat surface, away from the edge.

Although wearing ties is not nearly as common as it was, be careful, if you lean forward, that your tie, or your hair, doesn't get caught round the roller.

Anyone who has found beautifully rounded pebbles, shiny fragments of glass, or highly polished shells on a beach, has seen how continual fine random abrasion can shape and polish even the roughest surfaces.

Although tumblers provide continuous and distributed abrasion rather than intermittent and scattered abrasion, and the grits are very hard and very sharp, it still takes days to smooth off irregular stones, minerals, or pieces of glass.

Before starting, wash new or used barrels thoroughly using a brush and some mild detergent, and rinse them clean. This is particularly important as one left-over particle of broken stone or grit, tumbling for several hours, will leave scratches that are difficult to remove.

If the stones have broken edges, you may need to use 50% more 80 grit. If the stones are already fairly smooth, you may be able to skip the 80 grit phase. As with so many things, try it and see.

Select stones which are of similar hardness. Fill the drum about 70% full with the stones, add two heaped tablespoons of 80 grit, and top up with water to about 10mm above the tops of the stones. Fit the lid, put the drum on the rollers, and start the tumbler. It's OK to stop the tumbler and check the progress, but the stones may need several days, or even weeks. 80 grit breaks down gradually, so the stones might need another couple of days with new grit.

Empty the stones into a cloth-lined sieve, rinse them, remove them, and throw away the grit if it doesn't feel sharp. Don't mix up new and old grits. Don't accidentally flush away any grit as it will collect in the basin trap. Wash the stones, wash the drum, and tidy up.

Before moving to a finer grit, check the stones. Any imperfections that have not been ground away by now will be very hard to remove during subsequent tumbling.

Repeat the filling process, using 220 grit, and tumble for several more days. Again, it's OK to stop the tumbler and check the progress, providing grit doesn't prevent the lid sealing properly. Wash the stones, wash the drum, and tidy up.
Repeat the filling process, using 400 grit, and tumble for several more days. Wash the stones, wash the drum, and tidy up. Any grit remaining will produce scratches during the polishing phase.

Repeat the filling process, using plastic pellets to about 10mm above the top of the stones, but no water. The pellets buffer the fine cerium oxide polish. Add one tablespoon of cerium oxide that's been mixed with just enough water to make it creamy, and tumble for several more days.

Empty the stones into a cloth-lined sieve and rinse them. The pellets float, so you can skim them off. Wash the stones, wash the drum, and tidy up. Let the stones dry naturally.

Use plastic spoons to transfer the stones, particularly before the final polish, as metal can leave marks which are quite hard to remove.

Although tumblers are very robust and normally last for years, any service or repair used to need a return to Germany, Japan, or the US. The down-time was a serious setback for any small business, and the return shipping charges cost as much as a new tumbler. Kitiki tumblers are serviced here, in the UK.

Unless you deliver and collect your tumbler, it must be carefully protected for the journey: so it's a good idea to keep the original box and internal packing. If you don't have the original packing, find something that can be re-used for the return journey as we don't have any empty boxes.

Kitiki can't keep every part for every piece of equipment in stock all the time. Although we always order promptly, there's often a manufacturer's delay, a public holiday, a trainee delivery driver, traffic chaos, a world-wide material shortage, or some other complication.
I know waiting is distressing but, unless you're really competent and have tools and test equipment, don't try to repair tumblers at home.