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.
Glenmore Lodge National Outdoor Training Centre near Aviemore had designed and were creating a new garden for their facilities. It was felt that a training centre would benefit from having an outdoor space to encourage personal reflection.
They approached LaserFlair with the idea of creating a wooden ‘library’ consisting of oak ‘books’ to create a focal point. To add an element of fun, they wanted titles relevent to outdoor activities engraved on their spines. My favourite was Classic Rock.
How to make an outdoor wooden library
Glenmore Lodge provided a list of the titles they wanted engraved on the oak books. They cut the wood into blocks of different shapes and sizes to simulate a shelf of assorted books. Each book was shaped to give the impression of a spine along one side
LaserFlair advised on fonts and layout to get the look and depth of engrave for the right look. We chose a bold font for the text to make it easy to read from a distance, and made the text as large as possible to fit the width of the books’ spines. We decided on a deep engrave for a lasting appearance and texture as the books were designed to be touched and weather with the garden.
Laser engraving the books
Each block of oak was positioned in the machine so that the ‘spine’ was uppermost. We do this because the laser head is aligned vertically and engraves the horizontal surface below. We lowered the machine bed by 15-20cm so that each ‘book’ could be positioned at the correct focal distance from the lens. Maintaining focus is important to achieve good engraving quality. Finally, we raster engraved to create a pleasing 3D effect, and performed two passes to give extra depth to the letters.
Glenmore Lodge love their new garden feature. It gives a sense of intrigue and intimacy.
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.
I’m often asked if we can engrave recycled wood. Here’s an example of a project where we did just that.
We laser engraved two of these signs made from reclaimed pine for Old School Fabrications (OSF). They were for an exhibition for the National Library of Scotland in Edinburgh.
When the wood arrived for engraving, it was covered with nasty old green paint and looked awful! OSF had cut the boards to size as they were too thick for us. We just had to engrave them.
Engraving through to the good wood
We made a good, deep engrave to give a significant 3D element to the signs. This was particularly important as OSF wanted to sand the signs after engraving to get back to the good wood under the layers of paint. A pine is a softwood, this was easier to achieve than if oak had been used. Engraving using the same power and speed settings on the laser machine will always deliver a deeper engraving if a less dense wood like pine or larch is used rather than on a more dense wood like oak.
Old School Fabrications then took the engraved wood for finishing and treatment for outdoor use. As you can see, the transformation was incredible, and all the knots and imperfections in the wood added to the beauty of the signs. This picture shows one of them mounted in Edinburgh’s St Andrews Square by the pond, where OSF put a model crocodile to complete the African vibe!
We were lucky enough to get our hands on one of the signs the exhibition was finished. They were no longer required, so ours is in pride of place on the workshop wall. It’s a great example to show customers when they visit of how they can expect engraved wood to look. And it also shows just how well reclaimed wood can scrub up.
LaserFlair makes fun and funky acrylic jewellery for Jaggedy Thistle in Dunkeld. We laser cut their reindeer brooches in the run up to Christmas along with highland cows and Scottie dogs. This is how it all happens.
We need vector artwork to create items like this. Jaggedy Thistle provide the artwork for their bespoke products, and the acrylic in the colours they require.
Vector cutting detailed shapes
Vector artwork is very simple. It consists of hairline shape outlines, and the laser follows the lines in the artwork to cut out each shape. There is a vector line for each outline cut on a piece. In the case of the reindeer in the picture, we cut the eye shape first. When the body is cut, the whole reindeer can drop out of the acrylic sheet and is then in the wrong position to cut out internal detail. This is why we set the machine’s cutting order so that internal details are cut before outline shapes. We minimise waste by using our laser cutting software to tile shapes which maximises yield from the acrylic available.
Protecting the pieces
Acrylic has a protective film on each side to prevent the surfaces from scratching. We leave it on during production to protect the acrylic surface from the heat of the laser which causes discolouration near the cut edges. After manufacture, it protects the pieces during shipping, keeping each shape in perfect condition as acrylic is easily scratched.
When Jaggedy Thistle receive their delivery, they remove the protective film from each brooch. Then they add the red noses and brooch pins, and mount them on cards for sale. Aren’t they cute!
You’d assume that 3mm plywood is 3mm thick, wouldn’t you?
Wrong! With plywood, thicknesses are nominal, not actual. This is because plywood is made up of different layers glued together. 3mm usually has 3 layers, and the result is an actual thickness of 3.2-3.3mm. 4mm ply has another layer, and is usually 3.8mm thick.
Potential design disasters
This can create a whole worlds of pain for designers and manufacturers if they want to create products made up of pieces that slot into each other and require a good fit.
If you assume a thickness of 3mm and you design 3mm slots in artwork and then try to fit 3.3mm thick wood in the slot, it’s not going to happen. Or if 4mm ply were used, 3.8mm parts would be too loose.
Imagine making 300 reindeer kits for Christmas, sending the artwork to a maker, and getting back parts that don’t fit?
This could have happened to one of our earliest customers, but we made a prototype, realised the problem and fed it back to the customer. They tweaked the artwork before we performed the production run. This simple check saved our customer – and us too – a lot of time, money and heartache.
Always check that your designer and maker are speaking to each other to avoid disasters like this.