How to Make Sheet Metal Figurines with Crystals

20/03/2022

How Most Metal Figurines are Made?

The most common way to produce metal figurines is by casting. The ancient art of metal casting has been around for 7,000 years to create both manufacturing and fine art pieces. During casting process, molten metal transfers from a crucible into mould. After the cool-down, you have an object that perfectly replicates its original form.

Although casting is a relatively low cost process to make metal figurines, the metal surface finishing will be rough. And it needs to further polish to get a fine and mirror metal finishing. This is okay if the metal part shape is simple and flat so that it has a large surface area for the polishing wheel to work on.

However it is not easy if the metal figurine has lots of details. This will require very small grinding tool to polish both the protrusion and cavity features, and make sure the workpiece without sand holes and deformation. And most importantly to obtain a perfect mirror-like metal finishing.

To achieve this standard, it requires tremendous skilled labour and it is difficult to guarantee the quality is consistent enough at a reasonable production cost.

Pioneer of Sheet Metal Art Cold Working

Crystocraft was the very first in the gift industry to boldly apply the cold stamping / forming / working technique to produce delicate metal figurines art and giftware. Crystocraft has been using this production process to achieve exquisite, smooth finish and high-quality consistency of our metal parts.

Cold working requires much harder and precise toolings in order to deform the steel sheets. For example you need diamond to cut glass, because diamond is harder than glass on the hardness scale.

However we need tremendous time, effort and investment to prepare series of highly precise moulds with hardness stronger than steel, before the metal figurine art can be born to live. That’s why this cold working technique applying to metal art is not common in the metal gift market. And most of the metal figurines you can find on the market are from metal casting, or alloy injection moulding.

Crystocraft has been the pioneer of cold working application in metal figurines art since 1980s. We are committed to preserving this craftsmanship in the industry because it is the core of creating the perfect gift, of creating special heartwarming moments.

Everything Start with Figurine Design

Our metal figurine creation journey begins with product design. Our designers and Crysocraft team do extensive research on the market as well as the topic and scope, to make sure we thoroughly understand what exactly we would like to achieve. We strive to create something unique and exciting that can become timeless masterpieces; bringing joy and heart-touching moments to our customers.

Our designers will first hand sketch different concepts. Each concepts will have their own style and unique features that appeal to target market. And at this stage, the technical team will access the artistic and aesthetic features, and determine whether they can express fully within the technical constraints. By mapping out different options and solutions, we shortlist the “winner” which satisfy both the market, technical boundary and commercial considerations.

Once we pick the perfect winner, our designer will create plaster models to further detail the three dimensional design outlook. For organic figurine shape it is more desirable for our designers to use plaster to model. We also use 3D software such as Rhinoceros to create 3D models. Our 3D printers can print out prototypes which exactly resemble the 3D models within couple hours.

Sheet Metal Parts Design

Cold working is quite different from casting & injection moulding, which uses the mould cavity to cool and solidify molten metal to obtain the final workpiece. For our cold working technique we use raw steel sheet and have it cut and deformed by hydraulic press machine, to obtain our desired metal figurine parts. Lastly we weld them together to form a three dimension metal art figurine.

It is a bit similar to how automakers manufacture car body. Huge hydraulic press machines cut and deform raw steel sheet to create different body parts. Different metal parts are welded and assembled together with robotic arms or manually.

Based on our engineers’ extensive experience, they breakdown the figurine design into different metal parts which are feasible to produce with our pressing machines. The drawing below illustrates different metal parts needed to produce in separate pressing processes.

Upon finalising on how the metal parts should split, our engineers will make technical drawings of all the metal parts with exactly dimensions. The drawings will then pass on to the tool makers and machinists for the next stage.

Blanking & Forming Tools & Dies Making

Technical Drawings of Tooling

Based on the parts drawing dimensions, our tool makers will begin moulds and dies design. They will need to issue technical drawings for our machinists to under the exact requirements so that they can proceed their work.

Blanking Process

Blanking is the first process to produce parts from steel coil or sheet stock. Blanking produces the outside features of the component, and the blank will pass on to other stamping and forming processes.

Blanking Mould & Die Making

The hardness requirement of the tool and die is very high because they need to be able to shear the steel sheet. First the machinists will mill and grind the tool base blocks to the dimensions required. Then they will take the blocks for heat treatment to further increase the hardness. After the heat treatment process, the tool base block cannot be machined by a milling machine because the blocks has equivalent hardness as the mill cutter.

At this stage, only EDM wire cutting can further work on the tooling blocks. EDM wire cutting is a slow machining process but it is very precise. The machining tolerance can be below 0.005 mm. This dimension tolerance between the cold work tooling is crucial and needs to be very precise, in order to obtain nice and clean edges of the blanks. Even for forming and drawing processes, a precise matching of mould and die will ensure the final workpiece has all the figurine design details show up nicely and consistently.

Forming / Drawing Process

To make the three dimension shape, the blank will have to “formed” or “drawn” by the presses. The steel sheets we use are a bit ductile so that they can stretch a bit to form the desired shape.

However we have to avoid having sharp features which can cause shear during the forming process. In addition, sheet metal will “spring-back” after the deforming force is removed from the workpiece. So it takes some trial and error to determine the suitable parameters for a successful production.

Drawing Mould & Die Making

Drawing tooling involves a mould (cavity) and die (protrusion). Same as the blanking tooling, they require hardness higher than sheet steel. First the machinist will take the mould and die base blocks to heat treatment and make it extra hard.

Our tool makers then need to make a pair of “copper dies”. Copper is a much softer material to work with compare with steel. It is much easier to use milling machine and carving tools to get the desired shape and dimensions.

Finally, using sinker EDM machine mounted with the copper dies to get the desired cavity out of the hardened steel mould blocks. This is a slow process and will take 12 – 24 hours to machine a cavity, depending on the size and precision needed. To make the tooling dies it is just the opposite. Drawing toolings in most cases are more complicated than blanking tooling and require much longer time to build.

Piercing Process

After the top part of frog body forms into shape, piercing is the next process to make holes on the metal parts.

Not all holes and patterns can finish in one single press machine. Sometimes we need to split into several piercing processes because some holes are not on the same flat surface.

Countless Hours to Create True Masterpieces

To create from scratch for a figurine art like this frog, will take around 3 – 6 months of tooling development which involves different area of metal manufacturing expertise and craftsmanship. Below shows the total around 10 tooling sets for our large press machines.

Other than the moulds and dies for the larger press machines, numerous small hand presses needs mould and die sets to produce smaller metal parts. These small hand presses toolings also require similar manufacturing processes.

Welding Assembly Jigs Design

Next stage we will be using electrical pulse welding machines to weld the parts together. Jigs & fixtures are necessary to hold the metal parts in a correct position before the welding process. Also our welding experts will tune the electrical pulse in such a way that the weld joints are strong enough, but yet with no visible “scars” or damages to the workpieces.

Electroplating

After the welding process, the next stage is to put on a nice final metal finishing – electroplating process. The metal parts will first get cleaned thoroughly in ultra-sonic bath to remove the oils and greases. The first layer will be copper plating of 20-30 microns to smooth out the metal surface and give a mirror finishing. The next plating will be nickel of 3-5 microns for a strong protection and enhance mirror effect. And final plating layer can be chrome / gold / rose gold / gun metal depending on the colours required by our customers.

Set Crystals on Metal Figurines Parts and Package to Ship

Finally the electroplated metal parts will go through quality check, and get registered in our warehouse. According to customer order’s requirement, we will set the crystals on the metal figurine parts with pliers. The crystals are mounted and tightened with metal fingers integrated with the metal figurine parts.

Final stage is to package the products and ready to ship out to our customers worldwide.

Below video shows how we set crystals on the metal figurine parts.