April 12 Make a finger jointed laser cut box
Creating a tightly fitting finger jointed box can seem complicated, but there are a few fantastic online resources that help to make this project easy.
To create your design for laser cutting a box with finger joints, head over to MakerCase or MakeABox. You’ll need to plug in your desired dimensions, material thickness and a few other details. A custom generated design will provide you with notches that snap together to create the walls of your custom sized box.
If you are not sure what material to make it from, head over to our materials page to see the wide range of materials we stock.
Here are a few key things to consider when designing for your laser cut finger joint box:
When laser cutting, a small amount of material is burnt or cut away by the laser beam. This is called kerf and is essentially the width of the laser beam; imagine cutting a piece of wood with a saw – the saw would cut away the timber that is the same width as the saw blade.
Kerf width varies between materials and is generally minimal (<1mm) but can be an important consideration when making a finger jointed box. To err on the side of looser finger joints, enter smaller kerf into the automated box design generator; conversely, if you are looking for a tighter joint you can enter a larger kerf into the automated box designer generator. The larger the kerf, the looser the join so you may need to scale up your joins.
In order to achieve the perfect tolerance for tabs and finger joints we recommend running a series of tests – set up your design with some variants to allow for trial and error.
See below for a rough guideline for kerf allowances, these measurements can be use as a starting point for your digital design.
Acrylic 2-3mm 0.18mm
Acrylic 5-8mm 0.21mm
Plywood 3mm 0.3mm
Plywood 6mm 0.25mm
Veneered MDF 4mm 0.16mm
Boxboard 1.1mm 0.08mm
Boxboard 2.3mm 0.12mm
Again, this information should be used as a starting point and we highly advise cutting a number of tests (ranging in kerf width sizes) to see which kerf gives the tightness you want with the notches.
2. Material width
All materials require different power settings when laser cutting. Thicker materials generally require more power, and have a thicker kerf. Material thickness should be considered when making finger joints, if your notches are deeper than the thickness, the ‘fingers’ may protrude at the ends.
3. Test and Prototype
To achieve your desired fit, we always recommend testing and prototyping your box. We recommend erring on the side of slightly looser joins, and using a small amount of wood glue to secure. This can help to avoid inevitable minor differences in material thickness and kerf.
Websites such as MakerCase or MakeABox provide a quick laser cutting design for a box with finger joints and are great starting point for your design. To achieve the perfect finger jointed box, you will need to plan for some trial and error with your prototyping process.
For further information on general laser cutting, please check out our FAQs for some guidelines.