Lasering the Model Armstrong Cannon
by John
This is the Queen Victoria emblem and motto on the original cannon at Port Fairy, Victoria.
The “Victoria Regina” emblem, and Order of the Garter slogan motto.
And this is what is now lasered onto the model cannon..
Pretty good, Hey? On the model, the emblem is 20x12mm. It was downloaded from the internet, edited with Corel draw, saved as a BMP file, and then lasered onto the steel model barrel. This is a photo of the emblem on the model cannon. The rectangular background will disappear with polishing.
It was made with a 30 watt fibre laser, driven by its owner, Stuart Tankard. It took about 30 minutes, 200 passes. Shows up my substandard turning.
Shows the emblem appearing after 100+ passes.
and this is an enlarged image of part the laser engraving.
I have some videos of the process, and I will make them available after some editing.
This was incredibly exciting. The model cannon requires more polishing, and colouring with a gun blacking chemical.
We also engraved the cannon weight, sight marks, and year of manufacture on the trunnions. I will post those photos when available.
johnsmachines 
Hello John, More superb attention to detail.
Which steel colouring process are you planning? Be wary, hot blue methods use very alkaline solutions that will dissolve copper also variable section thicknesses will produce variable shades and colours.
In my experience cold rust browning then boiling to covert to ferric oxide is best for variable section thicknesses and was the original process used. I can give you details if you are interested.
Robert
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Hi Robert, and thanks. Nothing definite yet about steel colouring, and my knowledge on the subject is minimal. So I would appreciate any advice and information. Gun blueing solution was one option. John
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