Lortone 3A Rock Tumbler

Description

Lortone 3A: the compact American classic

The Lortone 3A rock tumbling machine is one of the best-known compact rock tumblers in the world. This proven American model is designed for hobbyists, mineral collectors and jewellery makers who want to work with one carefully prepared batch at a time.

Unlike many modern plastic beginner machines, Lortone opts for a simple and reliable construction. The machine has a metal base, a separately replaceable drive belt and a durable rubber barrel. No complicated programmes or fragile digital controls, just a solid rotary rock tumbler that does what it was made to do.

The Lortone 3A is compact enough for a workbench, shed or hobby room, but large enough to process around one kilo of stones per grinding stage. That makes it an excellent middle ground between small toy-like rock tumblers and larger machines for multiple or heavier batches.

A proven Lortone design

Lortone has been manufacturing machines for cutting, grinding and polishing stones since 1978. The American brand is particularly known for its robust, clearly designed and easy-to-maintain barrel machines.

The 3A is one of the brand’s best-known models. The machine has deliberately been kept simple. You place the filled barrel on the rollers, plug in the machine and let it run for the required grinding stage. It is precisely this simple technology that makes the Lortone 3A attractive to users who value reliability more than digital timers and automatic programmes.

Parts such as the drive belt, bearings, barrel and motor can be replaced individually. As a result, a normal wear part does not automatically mean the end of the entire machine.

0.8-litre rubber barrel

The Lortone 3A comes with one rubber barrel with a capacity of approximately 0.8 litres. The European supplier states a practical capacity of around one kilo of stones. The exact amount depends on the size, shape and density of the stones used, as well as the amount of filler media and water.

Lortone identifies this model internationally as a machine in the 3 lb class. The barrel is mainly intended for smaller stones. The manufacturer recommends stones up to around 1¼ inch, which corresponds to about 32 millimetres.

For proper tumbling action, do not fill the barrel solely with a few large stones. A good batch contains stones of different sizes, so that smaller pieces fill the gaps between larger ones. When volume is lost during grinding, suitable ceramic or plastic filler media can be added.

Noise-dampening rubber barrel

A major advantage of the Lortone 3A is the fully rubber barrel. Rubber dampens the sound of rolling stones considerably better than a hard plastic barrel. As a result, the machine sounds quieter and less sharp than many cheaper rock tumblers.

No rotary rock tumbler is completely silent. The stones continue to roll against each other inside the barrel, and that remains audible. For that reason, it is best not to place the machine in a bedroom or living room, but in a stable and well-ventilated hobby room, shed, garage or outbuilding.

The rubber barrel is not only noise-dampening, but also hard-wearing. The material absorbs the constant movement of the stones and helps reduce damage during tumbling.

Special profile for proper tumbling action

The inside of the Lortone barrel has special ribs. These help lift the stones as the barrel rotates, after which they move back over and alongside one another.

That constant rolling motion is essential for an even result. If the barrel is too empty, too full or filled incorrectly, the stones may only slide along the inside wall. With a properly balanced load and the ribbed barrel profile, you get the desired motion that gradually removes sharp edges and rough surfaces.

Suitable for around one kilo of stones

The Lortone 3A is ideally suited to smaller and medium-sized batches. The European product specification states a practical capacity of around one kilo of stones. That is enough to make a nice collection of tumbled stones, without immediately needing large quantities of grit and rough stones.

The machine is suitable for, among other things:

• beginners who want to start with a high-quality machine;
• hobbyists who process one batch of stones at a time;
• mineral collectors;
• people who want to polish stones they found themselves on the riverbank or beach;
• families and supervised educational projects;
• jewellery makers and goldsmiths;
• tumbling suitable small metal parts.

Which stones can you tumble with the Lortone 3A?

With the right grit, the Lortone 3A can be used for many well-known tumbling stones, including:

• agate;
• jasper;
• rose quartz;
• rock crystal;
• amethyst;
• sodalite;
• tiger’s eye;
• aventurine;
• suitable river stones and pebbles.

For best results, process stones of roughly the same hardness within one batch. If very soft and hard stone types are tumbled together, the soft stones may be damaged while the hard stones are still not sufficiently ground down.

Not every stone is suitable for a rock tumbler. Brittle, highly porous, cracked or very soft stones may break apart during the process or damage other stones.

Grinding stones in four steps

A complete grinding and polishing process usually consists of four successive stages:

1. Coarse grinding: sharp edges and larger irregularities are removed.
2. Fine grinding: the surface is made smoother and more even.
3. Pre-polishing: the final fine grinding marks are reduced.
4. Polishing: the stones receive their final shine.

Each stage usually takes several days. A complete process therefore often takes around four weeks. The exact time varies depending on the stone type, batch and desired final result.

After each stage, clean the barrel, lid and stones very carefully. A small amount of leftover coarse grit can cause new scratches in the next stage.

Compact and energy-efficient in use

According to the supplier, the European 230V version of the Lortone 3A has an average power consumption of around 20 to 25 watts. Actual consumption may vary slightly depending on the load, mechanical resistance and mains voltage.

Because of its limited energy use, the machine is suitable for the long grinding stages required when tumbling stones. During a stage, the machine should usually run continuously; stopping it frequently can cause the contents to compact and the stones to damage one another.

Simple maintenance extends service life

The Lortone 3A is simply built, but it does require some maintenance. The manufacturer explicitly states that the machine must be oiled periodically. Follow the instructions in the supplied manual for this.

Also check regularly whether:

• the drive belt is correctly in place;
• the rollers are clean and can turn freely;
• the barrel is clean and dry on the outside;
• the lid and sealing edges are free from grit;
• the machine is standing on a flat, stable surface.

Do not allow spilled slurry to dry on the machine. Also, never flush used grinding slurry down the sink or toilet. The material can harden and cause blockages. Let it settle or dry out and then dispose of it with the residual waste.

Technical specifications Lortone 3A

What is included?

• Lortone 3A rock tumbler;
• one 0.8-litre rubber barrel;
• lid and closing parts;
• manual.

Please note: the standalone machine does not include stones, grits, polishing powder or filler media unless these are explicitly part of the chosen bundle.

Lortone 3A or a larger rock tumbler?

The Lortone 3A is especially suitable if you want to process one batch of around one kilo at a time and are looking for a compact, proven machine. For regular use, this is a significant step up from simple plastic beginner kits.

If you want to process two batches at the same time, a dual machine such as the TRM-2A is more suitable. If you are mainly looking for maximum German build quality and the option to add a second barrel later, the TRM-1A may be a better fit.

However, the Lortone 3A remains a particularly attractive choice for anyone who wants a compact machine with a long-standing reputation, a rubber barrel and a design that is easy to maintain.

A reliable first machine for years of use

The Lortone 3A is not a toy tumbler, but a genuine compact rock tumbling machine from a manufacturer that has been active in the lapidary world for decades. The combination of a durable rubber barrel, reliable mechanical technology, low average energy consumption and replaceable parts makes this a sensible choice for both beginners and experienced hobbyists.

Anyone who wants to process one batch of stones at a time and is looking for a compact rock tumbler with a proven reputation will get a true American classic with the Lortone 3A.