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.
Customers request all sorts of weird and wonderful commissions. Customers have lovely ideas to personalise gifts that are only limited by their imaginations, so no two jobs are ever the same.
A customer approached us to ask if we could engrave a pair of matching wooden tankards. He’d commissioned them as gifts for friends for their festival themed wedding or ‘wedfest’. If possible, he wanted to personalise them to make them extra special. Perhaps they would become family heirlooms to be treasured for years to come.
Engraving cylindrical objects
It is possible to engrave cylindrical objects, but this has its challenges. The laser needs a flat surface to focus on for best results. If the laser beam loses focus, engraving quality suffers and becomes fuzzier. The more out of focus the beam becomes, the worse the effect is.
We suggested that for something a little different and to maximise the chances of success, we could engrave the tankards vertically. This tactic would allow the laser to focus on the relatively flat spine of the cylinder. It worked a treat and you can see the results in the photo.
Top tips for engraving cylinders
We used our 100mm focal length lens to compensate for the slight curve on the circumference of the tankards. We performed a nice deep raster engrave to give a 3D effect on them, and the look really suited the chunky tankards. My customer was delighted with the results.
We’ve been branding stainless steel cocktail keys for Panch Drinks recently. They’re made in three sections for measuring fixed amounts of sweet, sour and strong ingredients, allowing cocktail recipes from mojitos to Moscow mules to be mixed to perfection every time.
These measures are made from stainless steel. Our laser can engrave some types of metal, and stainless steel usually gives good results. We had to use Thermark metal marking paste as the laser can’t engrave the metal directly.
The circular bases of the cocktail keys are only 50mm in diameter, which means that logos must be small to fit the space. As a rule, the smaller the logo is made, the harder it is to reproduce the fine detail when engraving it. Thick lines become thin, and fine detail that would look great on a large scale becomes almost indiscernible when scaled down to a few centimetres wide. In this case, we had to remove all the detail apart from the text, and even then I had to engrave some samples to make sure I could get good engraving results.
How does Thermark work?
Thermark is a mixture of pigment and glass particles. When the laser engraves it, it melts the glass and traps the pigment onto the metal surface, forming an enamel finish for a durable, weatherproof mark. Perfect for using in bars!