Guilloché

Guilloché

Guilloché is a term that encompasses the technique and machines that engrave or impart artistic designs onto precious metals or items using a straight cut or chiseling motion. Chris uses any combination of these techniques to decorate the rings and endcaps of his flutes. 

The machines that accomplish this can be divided into three types, two of which have been around for many hundreds of years.

The Rose Engine

This Rose Engine was made by Jean Gnagi, Chaux de Fonds, Switzerland in 1871. It found its way to the Jewellery quarter in Birmingham and then eventually to Chris.

Rose Engines have been around for hundreds of years.  Examples of their work can be found on many old flutes,  including Rudall and Rose. They impart beautiful patterning upon the sides and ends of cylinders through a single cutting tool. Although this is done using a machine, a good deal of skill and patience is required to produce good work . Most of the intense effort for Chris was getting the machine to run true (he had been told that it was left in bits before the second world war). Chris had to make missing parts and then assemble the machine before constructing the three flute specific bronze rosettes that he uses to generate patterns.

Straight Line Engine

This machine was made by George Plant of Harborne, Birmingham, around the year 1920. It is an adaptation of the Rose engine for producing patterns on flat surfaces. Chris only uses this machine in flute work for doing a "starburst" effect on silver endcaps. 

Brocading Engine

This machine was made by M.J. Brohen and sons, in Attleboro, U.S.A. probably in the 1920's. It is the most difficult to use of the three guilloché engines that Chris uses. Getting good results requires a great deal of artistry and patience both in constructing the tooling and cutters, but most of all designing, then constructing the patterns that are used to produce the designs. More information on this process can be found at the bottom of this page.

Guilloché video

Here is an excellent explanation of Guilloché by a very skilled professional.



Making Rose Engine "rosettes"




These are the "master" patterns used on Rose engines and comprise of a bronze ring with a series of waves machined around the sides and front. They define the shape of the "wave" (its amplitude and shape of curve) and its density (how many of these waves go around the object that is being engraved). Because flutes are all around a certain diameter, "rosettes" need to be formed to match that size so that the patterns appear correct and distinguishable.




Roughing out



A section of sawn bronze pipe machined out on the lathe to the finished  outside dimensions


Machining the wave


Chris works out the geometry of the waves on the drawing board and then traces out one wave, four times full size onto a steel template. The "waved shaped" template is then used in conjunction with a rotary table and three dimensional pantograph to machine out the waves on the machined bronze blank.


Finished rosette


Finished rosette prior to fitting on the Rose engine



Finished rosette mounted on Rose Engine

The rosette in place shown third from the right. It produces the snakeskin pattern

Making a Brocade master cylinder

Brocade Engines employ two types of master patterns, a disc and a cylinder. The disc pattern produces just one form of its pattern, but the cylinder, through gearing can produce many more. In this section, Chris shows how he made a cylinder pattern based on a 8-9th century Anglo Saxon cross that he found in the British Museum.

Chris found this wonderful object in the British museum. It is the remains of an 8-9th century Anglo Saxon cross found at Lowther in the Lake District.

Initial planning

The design is controlled by the diameter of the finished pattern roll. Here elements of the original design are experimentally fitted onto a projected circumference of the roll.

Design Work

Elements of the design are fitted into a repeatable pattern. The height and the amount of pattern repeats are determined by the Brocade Engines pantograph aspect ratio and gearing, and these have to be taken into account.

Clay template

A nylon holder for the clay was made twice full size. Clay was layed out in the bottom and then levelled using thickness templates. A tracing of the design is placed on top and the outline pricked through with a pin.

Sculpting

The pattern is then created by hand using clay. Chris did this by hand in order to get a human feel to the design. It may have been possible to create this on Chris's CNC router, but this might have appeared too "wooden".

Master template on pantograph with roll attachment

A latex mould of the clay design was made. From that, a hard nylon pattern was created. This was set up on a three dimensional pantograph with a roll attachment.

Bronze blank machined

The nylon pattern is traced over at a   2 : 1 ratio. Carefully and slowly the design takes shape...

Hand work

A long time was then taken working the bronze pattern using hand engravers under the microscope.

Testing

The bronze roll was put on the machine and lots of tests made. Adjustments were carried out on the master roll until an acceptable design was produced.

Finished Roll in place

Making Brocade master discs

Chris has copied old discs and made new ones on his small CNC router.

Original Brocade pattern disc

This is a beautiful original brass pattern disc probably used to engrave powder compacts. It was kindly loaned to Chris by David Wood-Heath.

Wilkes pattern disc

This pattern disc was made by Chris on his small CNC router. Custom discs can be made to produce designs or writing that can be used to engrave the tops of end caps or the side of rings.

Disc pattern engraving on rings

This picture illustrates what Pattern discs can accomplish on the side of rings

Testing and practice

Chris has a lot to learn about this machine. A lot of practice and testing is necessary....


Video title

Thanks

Chris would like to thank Jeremy Soulsby, David Wood-Heath and Peter Williams for all of their help .

Interested in Guilloché?

The Society of Ornamental turners :  http://www.the-sot.com.