We can engraved curved surfaces as well as flat ones, but it depends on the curve and the material. Here’s an example.
We engraved these beautiful beech coffee tamper handles for Made by Knock for their customer, Machina Espresso. They’re so tactile, and are perfect for engraving if you can work with the curved surface. That was the biggest challenge, along with getting the logo centred on the top. You can easily spot if engravings are out by a millimetre.
It’s all about focus
The principle is that flat surfaces should be engraved. This is because the laser beam is focussed vertically onto a horizontal surface. The distance between the lens and the material surface is crucial for high quality engraving. Lenses have specific focal lengths that should be adhered to for best results. Even a tolerance of plus or minus 1mm can be a problem depending on the material used and the lens selected.
These principles need to be adhered to more for sensitive materials like acrylic and metal where a reduction in engraving quality is very easy to spot. Wood, on the other hand, is much more forgiving.
My secret weapon
My secret weapon is my 100mm lens. It allows me to work with a curve of around 8mm, particularly if the material is forgiving like wood is. I’ve used it to engrave these tamper handles and mini wooden baseball bat muddlers for mixing cocktails. It is still important to keep engravings on relatively flat areas for best results.
Before we went into production, we engraved Machina Espresso’s logo on a few tamper handle seconds to judge the largest size the logo could be engraved to keep the logos on the flattest part of the handles. It was important to know at what size engraving quality would deteriorate, and to make sure that engraving results would be consistently high quality.