Power Carving

Anthony Bailey introduces rotary power carving, with tips on choosing tools and getting the most out of them

Rotary power carving is one aspect of carving that is rapidly increasing in popularity. It seems the bird carving fraternity took to it and since then it has been taken up by many other carvers working in many other forms. Let’s face it, this working method is not just used by carvers; there are jewellers, metal workers, engineers, model makers, stoneworkers and more who enjoy and capitalise on the benefits of rotary carving techniques. With the correct cutters and blades, power carving can be used to quickly give shape to a piece or – with a change of cutter or blade – be capable of the most delicate detailing. I am not saying that it is a cure-all approach to carving, but it is a route with considerable merit for exploration.

There are scores of products in this section of the market to suit all the various materials, shaping methods, detailing and finishing required and all to various budgets. Obtaining the items that you need is quite an easy process, but making the right choices can be somewhat intimidating when you first start.

In this article, I am going to focus on the two types of rotary carving unit: suspended items with flexible shafts and smaller, hand-held units often seen in DIY and specialist stores. I hope that this is an easy guide that will point you in the right direction with some top tips and pointers on tool choice, usage, safety and other bits and pieces that will help you on your rotary power carving journey.

Carving units

Having pruned a severely overgrown camellia shrub during the summer, I was left with a selection of curved and bent branches with a diameter of about 1/2in (1cm), perfect for carving my peapod and its peas, and it will be interesting to see how camellia wood carves as I have never used it before. Camellia is a light-coloured, close-grained wood and other suitable species could be cherry, beech, boxwood or any other tightly-grained timber. For holding my small carvings securely and safely while working, I use my versatile woodcarver’s chops, sometimes together with a small piece of non-slip mat wrapped around the carving held between its jaws.

Rotary carving units come in many shapes and sizes. Effectively they are nothing more than a unit that houses a motor, which in turn causes a spindle to rotate. Attached to this is a clamping device that allows the secure holding of cutters and the user to hold and manipulate the device safely and easily. Most units now have variable speed, which is very important for control and the ability to use different cutter types and materials effectively.

Depending on the type of unit, you can have the motor and holding device integral to each other and fit various cutter types into them. If required, a handpiece to accept cutters can be fitted on to a f lexible drive. Handpieces come in various shapes and sizes and can employ different cutter locking methods. Typically, these include a Jacobs-type fitting, which is tightened using a toothed key, a collet system which uses collets of various internal dimensions to suit the various shank sizes available and is spanner-operated to open and close. More recently there are keyless chuck units which have a twist-lock mechanism – although these are more commonly found on the smaller units like the micro-motors. These keyless units require the motor unit to be hung up near the user to facilitate the easy use and manipulation of the handpiece.

Other units have larger, more powerful motors which need to be hung up near the user. These have flexible drive shafts fitted on to them with interchangeable handpieces attached to accept cutters. Many units can be bought with accessory kits as part of a package, but these kits are generally a mix of cutters and bits and pieces that are more suited to use around the house than carving. Most units available now have variable speed options which allow you to change the speed to suit the material being worked on and the cutter size and type used.

Cutters and accessories

It is all very well and good having a rotary unit, but it is no use whatsoever without some cutters – also called bits and burrs – that will allow you to shape and refine work quickly and cleanly. Here are some of the options available and what they can be used for. There are myriad types with different shaft and head sizes, so try to pick the right cutter for the job at hand. Do not overload the cutters and motor with heavy pressure. This should not be an issue if you have selected the right cutter size, shape, speed and grit grade.

The trick is to match the cutter shape, size and coarseness of grit grade to match the work and material you intend to do. Most cutters and burrs come in one section but the cutting, sanding, and polishing discs can come as part of an interchangeable system with a shaft onto which various heads are fitted.

Whatever type of cutter, burr or bit you use, follow the manufacturer’s guidelines for correct working speed ranges for each type selected. Here is a very quick breakdown of the common types.

Diamond and ruby cutters

Available in a wide variety of grit grades, they can, depending on type chosen, cut wood, man-made wood boards, plastic, acrylic, polymer, ceramic, glass and metal. They are ideal for refining the surface and adding in fine detail. You find decoy and bird carvers use these a lot.

Carbide tooth cutters ▶

Available in coarse, medium or fine grades and various shapes. They have evenly spaced teeth and can be used on wood, man-made wood boards, plastic, acrylic, polymer and – check with the manufacturers first – some soft stones. They are ideal for the initial shaping stages of a project.

◀ Structured-tooth carbide cutters

Available in coarse, medium or fine grades, they can be used on wood, man-made wood boards, plastic, acrylic, polymer and – check with the manufacturers first – some soft stones too. They have randomly arranged teeth and are ideal for the initial shaping of a project.

Milled carbide
and HSS cutters ▶

These come in a variety of grades and are suitable for wood, man-made wood boards, plastic, acrylic, polymer and metal. They can be used to shape and refine work.

◀ Various sanding accessories

These are commonly made from diamond, ceramic, silicone, carbide and aluminium oxide. Available in a wide variety of shapes and materials there is an abrasive product to suit all materials available, just check with the manufacturer as to what is best. Used for shaping and refining the surface.

Man-made materials ▶

These include aluminium oxide, ceramic and many more man-made compounds. Check with the manufacturer details, but depending on what they are made from, these can be used on a variety of materials. Although they come in a variety of grades and can be used to shape work, they are typically used in the final stages of refining and adding detail.

Spiral cutters for
drilling and side cutting ▶

Pick wisely. Some cutters can be used for side cutting and others cannot, so check with the manufacturer to make sure you buy the right type. They can be used on metal, wood, man-made boards, polymer and acrylic.

◀ Polishing, sanding and accessories

Available in various types of wire or other materials impregnated with abrasive. Again, the variety on offer is huge. These are used to clean up and refine work. The differing shapes allow you to get into crevices and deal with textured surfaces where normal abrasives would remove too much detail.

Specialist cutters ▶

There are quite a few specialist cutters available which have cutting teeth at right angles to the shaft. Depending on the material they are made from, they can be used to cut wood, man-made wood board, plastic, acrylic and polymer. These are used for primary shaping.

◀ Cutting discs

These can be made from various materials and this will dictate which materials they can cut. There will be something available for every material you encounter. Some use a quick-change shaft arrangement.

Various types of buf fing accessories ▶

Again, there are many shapes and material types, but ultimately, use the shape and type you need to suit the shape and material of what you are working with. They can be coated with micro-polishes and compounds to refine applied surface finishes and used to clean up oils, waxes and other finishes. Polishing compounds are available to refine all finishes and materials you are likely to encounter. Such polishing systems are of ten overlooked but can be very effective.

Personal protective equipment

I am using eye protection, a face mask to protect my lungs and an extractor which sucks the dust and debris away from the work. Protecting yourself to minimise the risk from chips, debris and dust is a must. You can opt to use a full visor and a different type of mask, even a full-powered respirator – something like the Trend Airshield or similar is worth considering. In addition, if you carve near the body, a leather apron is a wise choice to prevent damage from cutter skids. Be careful of loose clothing too, as it can get caught in bits if a catch occurs. There are various ways and pieces of equipment to help with this issue, so find a set-up that works for you. But do not forget to use it. It is often the jobs that ‘just take a minute’ that cause accidents. Never take chances with your health.

Securing your work

It is vital for both success and safety that you are able to hold your work securely. Working with a clamping system or a vice that allows you to move the piece around and fix it in a variety of angles is ideal. It also leaves both hands free to hold the handpiece firmly. If you can use a clamp or vice effectively, then please do so, because they are the safest options.

Securing your bits and cutters

You must ensure that you secure your bits and cutters properly. You should secure the shaft of the cutter a minimum of half the overall length in the chuck/collect of the handpiece – but more is better. I tend to go in as far as I can, but of course leave enough proud so I can reach the work properly. Check with the manufacturers to see what they recommend. Also, if using a chuck/collet fitting, make sure the collet is the right size for the cutter.

Gloves

Many gloves are available that help you grip work securely while providing support and protection to your hands. Some people also use a glove on the hand in which the handpiece is held. Many choose one which minimises vibration in the areas that grip or support a tool.

It is best practice to take regular breaks when power carving and move your hands after doing so; 15 minutes at a time usually works for me – any longer and I get cramp or my hands become tired. Long-term vibration running through the hands coupled with repetitive holding can cause easily avoided problems.

Holding by hand

Clamping a piece is not always possible, so it may – depending on the size – be necessary to hold it in your hand. Some carvers even hold it in their lap – see earlier mention of leather apron. Of course, you need to have control of the work and be able to feel it, but you must protect your hand in case you slip with a cutter. I repeat, this should only be done as a last resort. If you choose to hold work in your hand, leather gloves afford better protection against toothed-cutters than woven-mesh anti-slash/stab or rubberised gloves which can easily become caught and wind in on the cutter teeth. Leather gloves will provide abrasion resistance, slash protection from cutters and they are long enough to protect your wrists too. Though, I repeat, this method is only recommended if you cannot find a better holding method.

Useful tips & advice