How to pick the best rolling mill!
Investing in a Pepetools rolling mill.
By Dave Wilson
So, you’re thinking of buying a rolling mill? Well here are my top tips for buying one and the different features you may wish to look out for.
A rolling mill is a considered purchase. But think of it more as an investment, in the long term it will save you time, money and increase your productivity as well as increasing the many possibilities of what you can do and make.
A good quality mill will be an investment in your business. But what makes a “good quality” mill?
The Pepetools models offer some of the best quality you can get for your money. Features like brass bushes reduce the risk of jamming. Case hardened rollers ensure toughness and longevity. Their new ductile frames offer incredible strength with a certain amount of flexibility in the steel, giving the perfect combination of strength without the brittleness. Their 4:1 gearbox gives speed and accuracy, with ease of use. The finish, styling and attention to detail are all things that define the Pepetools brand. The Pepetools mills are designed to perform day after day and give predictable reliable service for many years. But with so many models to choose from, where do you start?
Before you start - Annealing your metal
Although this is a buying guide to the models available, it's worth mentioning about annealing. As you work silver and gold with a mill, it quickly gets hardened and tough. Annealing is the process of softening metal to make it more malleable. With silver and gold, this is a simple matter of heating it uniformly with a soft flame to a dark cherry red color, Then quench in water. This reduces the stresses in the metal and makes it easier to bend and work within the mill. It also stops the wire from being too springy, especially important if you want to bend it into a ring or make jump rings later. It is important that when annealing you heat the whole piece of metal evenly with a soft flame. An annealing pan is a large metal pan filled with pumice or similar material. This allows a large item to be heated evenly and gently with a soft flame. Too aggressive and you can cause surface melting or fire scale. For this reason, you can apply flux to prevent oxidization. It is also advisable to anneal in a dark area so that you can clearly see when the metal glows a deep red. In bright light, it's easy to overheat the metal.
Top tip - Sharpie Trick
When annealing silver, a simple trick is to use a sharpie marker and draw a clear line on the surface of the silver. As you heat, you will reach a point where the sharpie mark disappears. Quench in water immediately.
Whilst you work your material through a rolling mill, it will quickly harden again. When you are working (for example) an ingot down into thin wire, you may need to anneal your metal several times throughout the process. You will feel the mills handle get harder to turn.
For busy studios where a lot of metal is being milled, and hence a lot of annealing is required, you may wish to consider a temperature-controlled annealing oven specifically designed for this purpose. In most jewelry cases a soft flame is sufficient.
Always ensure that your metal is dry before putting it through the mill, avoid any moisture on the rollers which could lead to corrosion.
Roller Width?
The first thing to decide upon is the width. By width, I mean the useable length of the rollers and hence the maximum width of material that you can put though the mill. I’m talking here about basic flat rollers. Pepe offer several sizes (widths) of mills from 90mm to 160 mm, with new models added regularly. Consider what you intend to make. Even for large bangles, you only need the metal to be an inch or so wide. In this case a 90mm entry level Pepe mill with flat rollers, should meet your needs. Of course, the length of your material is limited only by the space around it. You can roll any length of strip or wire without any real limits - but the maximum width is determined by the width of the rollers. Note that rolling a strip will make it thinner and longer, but not wider.
Above: Pepetools Ultra Mills in varying sizes, note the difference in the width.
Reducing stock.
Flat rollers have many uses, you can reduce strip and sheet material to a desired thickness. This gives flexibility of working, as you don’t need to stock every thickness. Note you can’t really make sheet thicker, the mill makes it thinner. But by just keeping a few thicker pieces, it’s easy to reduce them through the mill, to whatever thickness you require. This reduces the need to keep huge stocks in every size. It also reduces the need to put a job on hold whilst you order the required material. The flat rollers are also a great way to standardise material and make it uniform. This is especially useful with cast bars and ingots.
Texturing and Embossing.
Flat rollers can also be used for embossing, whereby you roll your metal with a leaf, lace, fabric or other material to impress a texture into your metal. You can even get special steel texturing plates for doing this. It’s important to protect your rollers when doing this. Imagine you want to emboss a leaf into silver. The usual method is to make a “sandwich” with your silver on the bottom, polished surface upwards. The leaf (or whatever) is placed face down on top of the silver and a sheet of copper or brass (softer than steel) is placed on the top, the whole sandwich is rolled through with a light pressure. The leaf will be imprinted into the silver. The copper is sacrificial in this instance.
Embossing. In this video (see pepetools.com) you can see Dave Wilson embossing a pattern into a strip of silver using the Pepe 130 Ultra Mill. On the bottom you can see the sheet of copper, the black leaves are bought decorations, flowers laser cut from thin steel. On top is the strip of silver. Right, you can see the pattern which has been embossed. The strip was later made into a bangle, earrings and rings.
Note the silver strip is thin, so the flat section is perfectly wide enough for this task.
The wide boys...
The larger, wider mills offer a couple of distinct advantages. With wider flat rollers, you can roll sheets of material, for saw piercing or forging. The wider rollers are also ideal for roller embossing. Put simply, the wider the rollers, the wider the sheet you can make or texture. A 130 flat roller will give you the maximum width for flat sheet and embossing.
The right combination...
The second advantage of having wider rollers comes when you use ‘combination’ rollers. These rollers have the traditional flat section, but also have a grooved section with V shaped or semi-circular grooves. These offer the best combination of versatility for most users, but the inclusion of the grooves along the roller reduces the width of the flat section. Typically, by around half. Hence, if you want the best of both, then the wider rollers will offer you more grooves, whilst retaining a good wide flat area. A 160mm combination roller will give you almost the same flat width as a basic 90mm flat roller, but also offer the additional grooves. You can also get rollers which are fully grooved end to end, ideal for making wire. But this does somewhat limit the versatility of the mill, as it would have no flat section (or you’d have to change the rollers).
Image. Pepetools combination rollers. Note the flat section and the grooves. The grooves on the right are for making D shape wire for rings.
So, for most users, combination rollers are usually the most versatile option.
Getting into the groove....
These grooved or combination rollers come in an assortment of shapes - V shapes, round and ovals. Grooves in the top roller correspond with grooves in the lower roller, and typically you will see several grooves in diminishing sizes. The main use for these grooves is to convert rough or cast material into useable bars and wire. A cast ingot for example, can be successively worked though V shaped (square) rollers, rotating each time to eventually form a square cross section. This square bar can then be reduced in the flat section of the rollers, to create strips for rings and bangles. Alternatively using successively smaller V grooves will reduce the square bar further, to create square wire. The thin square wire can then be pulled through a draw plate to make it round.
Recycling scrap...
This ability to turn rough cast material into usable bullion is by far the greatest strength of the combination mill. Don’t weigh in your scrap silver and then pay full price for new processed metal. Scrap can be melted down in a crucible using an oxy propane torch. A little borax should be added to help with impurities and if possible, it’s a good idea to add a little “pure” material to keep the standard up and account for solder and other impurities in the scrap. For example, if melting down sterling silver scrap, it’s a good idea to include a little 999 silver to keep the proportion up and ensure the final material is up to the required standard. The molten material is poured into an ingot mold and once cooled it can be passed through the mill to turn it into the desired size and shape. In my own workshop, nothing leaves until it is a finished piece of jewelry (at full price). No material is ever sold for scrap.
Pepetools Ingot moulds. Pour in your molten metal, to form an ingot then transfer to the mill for rolling
Wedding rings – I Do!
You may also see semi-circular grooves just on the top roller, above a flat section. These grooves will produce D shaped wire, idea for making rings and ring shanks. Shanks can sometimes be expensive to buy, in comparison to regular bar and stock. With a Pepetools combination mill it’s simple to make your own ring shanks in whatever size and shape you require.
Pepetools have also recently introduced the “comfort” roller which has round and oval grooves. This will reduce square or round material into a flattened oval cross
section. This oval bar can then be used to make the popular comfort fit
wedding bands.
above, Pepetools new all wire rollers, with V shaped grooves, comfort fit, small bezels, triangular and D shape. Ideal for making all your own wire, bezels, and ring shanks, at a fraction of the retail cost. Reducing material costs and increasing profits!
The right gear...
An often-overlooked feature is the gearbox. In its most basic form, a rolling mill handle is simply attached to the bottom roller directly. Therefore, one turn of the roller, requires one full turn of the handle. All Pepetools current models feature a gearbox which both increases power and reduces user movement. The Pepetools 4:1 gearbox means the roller rotates four times for every one turn of the handle. Or vice versa, a full turn of the rollers only requires a quarter turn of the handle. Hence you can work long strips of metal without having to laboriously wind the handle.
Above, Pepetoosl 4:1 gearbox.
It is paramount that the gearbox is well made and strong, to cope with the large loads and stresses. With he Pepetools mills you will note they have fully
enclosed and lubricated gearboxes, with small, strong and precisely meshing gears. They are designed to give you the ideal ratio of force and speed whilst maximising their longevity. Combined with Pepetools forged (not cast) handles these gearboxes give ease of use and increased work speed. Details like solid wooden hand grips make the Pepetools units comfortable to work with day in, day out.
Power to the people...
Despite their fine precision, the Pepetools mills can produce an incredible amount of force and pressure between their rollers. The use of a handle gives you a direct attachment to the mill and gives you feedback as you work. When it feels difficult to turn, you can back off the rollers a little. Vice versa, once the material has been fully reduced you will feel the handle get easier to turn. So, for general jewellery making jobs a comfortable handle and quality gearbox is a great combination of power and speed. However, when repeatedly making long lengths of wire, you could still find yourself doing a lot of winding. Whilst not usually difficult, this can become time consuming. But Pepetools offer a solution to this problem too.
The solution to repetitive winding is the Pepetools Power Mill. Here they have replaced the handle with a huge high-power electric motor, which in turn uses a modified gearbox, to drive the mill. You may think that such an addition is simply for the lazy jeweller, but the power mill has many advantages... When creating wire, the power mill can rapidly speed up the process, passing yards and yards of wire though the rollers in seconds, with a precise uniform speed. You can quickly reduce a cast ingot into several feet of wire within just a few minutes (remembering of course to anneal the metal).
Pepetools 130mm Ultra Power Mill
Hands free operation.
Another big advantage of the power mill is the fact that both your hands are free, as you don’t need to wind. Hence you can use both hands, feeding the material in with one hand and collecting it with the other hand at the back. This together with the motor allows you to work exponentially faster, and much safer. Also, one person can do so much more, as you don’t need to wind or ask a colleague to. The lack of a handle also reduces the space needed for a power mill, again increasing flexibility of placement options. Less space, less work, more productivity.
With great power comes great responsibility...
As mentioned, the mill can produce incredible pressure between the rollers. With the addition of the motor, the user is now detached from the unit. Whilst freed from winding the handle you are also detached from the sensory feedback. What may be difficult to wind by hand, the motor will push though with ease. Hence a little caution needs to be observed, and work as you would manually. Turn the adjustment lever, just a little at a time, and reduce the material gradually in small stages. This approach will also reduce the possibility of stress cracks in the material or creating sharp burrs when too much material is forced through the V grooves. Use the power to increase speed, uniformity and productivity but not to ‘force’ material through. The Pepetools power mills are fitted with safety fences and emergency stop buttons for your added safety.
At the double...
As mentioned previously, the combination rollers offer a compromise between having useful grooves, but a reduced flat area. So, what do you do when you want it all? You want the maximum flat area for large sheets. But you also want to make wire and strip using the grooved rollers. Well... you can of course remove and replace the rollers, but with a gearbox this is time consuming and not really something that you’d want to do daily. But once again Pepetools has a solution for everything. You could of course buy two mills, but this requires increased cost and space requirements. At the top of the tree we have the ‘double’ units. These are basically two mills in one, having four rollers powered by a single electric motor. The most useful arrangement is to have full width flat rollers for sheet and embossing, and a set of fully grooved square or round rollers for making wire. When you need the ultimate in efficiency and flexibility, the double Pepetools ultra mills offer the best of everything. Ideal for a busy workshop or small commercial environment.
Whilst it may at first seem like an extravagance, it can be set up just once with the desired configuration of rollers and it’s always ready to go, whatever the task at hand. The double units share a base and motor, so also offer a cost saving over buying several separate units. They also greatly reduce the workspace required over having two separate units on the desktop. They provide a compact one stop solution for processing material.
Pepetools Double Powered Ultra mill
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