Using a laser to quickly make wooden items is easy. However, to make nicely finished items requires more than just a “cut-and-go” approach. I made some travel chess sets by cutting and engraving the board and pieces using a laser. But this was just a very small part of the project. Here is the finished project after many hours of designing, sanding, cutting, staining, more sanding, gluing, sanding and more sanding (available here).
This chess set is based on another set that I have, but people dislike the pixelated pieces (see/get the pixelated set here). Using the same layout as with the pixeladed set I redraw the pieces, first in Corel Draw. I then added the shade in Photoshop and ported it back to Corel to finalize it before sending it to the laser.
(In previous projects I started with drawing the images first using Photoshop and saving them as .jpg. I then generated the vectors and exported them as .ia files from Photoshop. I imported the .jpg into Corel and overlay the .ai vectors. This allows me to make the cuts after the images have been engraved, exactly where the outline paths are generated (I used it in several other projects). HOWEVER, the paths that are generated from a bitmap type image are not exact. This means when a circle is converted from a bitmap to a vector, it is not completely round as the path is followed where the pixels are located. These which are never at a high enough resolution to be perfectly round (for the pixelated chess set I fixed ALL the lines in Corel since the lines are supposed to be straight but the path generated is often not). The inaccuracies creates a small problem as pieces are not 100% symmetrical. It cannot be seen by eye but since the front and back pieces in this chess set is the same it is possible to place the piece backwards when storing. This asymmetry can make the piece get stuck when placed in backwards. – Starting with the vectors, as I done in this project is much thus much faster and mode accurate.)
In addition to the wooden parts I also design the leather hinges, feet, latches, and cardboard sleeve. The design of the board and pieces, and other parts (including some test cuts), takes the second place for most time spent on this project.
I use a custom jig to hold the plywood flat when cutting. This is probably the best jig that I have ever made since plywood is never completely flat and the focus of a laser is always exact (this is one of the main reasons why I was considering the Glowforge laser, which has auto-focus).
The boards and pieces are engraved and cut at an angle (4 degrees), relative to laser bed layout and wood grain (see below). There are several reasons why I do this. The first is that it ensures that the pieces are less likely to break. Since I engrave on both sides there is a chance that the wood in the middle sheet (there is only 3 sheets in this plywood) would need to carry most of the strain. If the grain in this sheet is in the wrong direction the pieces would could break more easily. However, when engraved at an angle the grain cannot be parallel to the weakest point and the pieces are stronger. I also found that engraving at an angle makes the horizontal lines slightly lighter and the vertical lines slightly darker (this is due to the laser only flashing quickly when engraving thin vertical lines part while being continuously on while engraving thin horizontal lines – when engraving lines at 90 degree angles). The engraving is thus much more even. A larger angle would probably be better but 4 degrees is the maximum I can turn the parts and get the same number of boards cut.
After the pieces are engraved and cut, I engrave them on the other side.
I remove the pieces and make a deep engraving to create recesses for the leather hinges and feet. This allows the leather parts to sit in the wood. It also ensure that the parts are glued much more securely. I add masking tape at this stage to reduce the amount of sanding needed to clean the part later.
Next the feet and hinges are cut.
Once all the parts are cut, the biggest part of any woodwork project begins – sanding. First I remove the burrs on the bottom of the pieces where they were attached to the wood. This means they will slide more easily into and out of the recesses when the board is assembled (I also sand the burr in the recess).
I sand everything with 400 grit sandpaper to remove all the laser burns and stains, being careful not to sand to deep and remove any of the engraving.
I stain the dark pieces with light walnut (this gives a similar color to the dark squares on the board).
After drying each piece is sanded again, very gently with 800 grit sandpaper. The light pieces is also sanded at 800 grit to give a silky smooth feeling to every piece.
During this time the board is assembled. The front and back parts are glued together.
After gluing the edges are given a final sanding and the corners slightly softened.
The leather feet and hinges are glued in place. Small screws are added to the hinges, more for aesthetics than anything else. Everything is clamped overnight.
The last part to make is a sleeve for each set. This is also done on the laser. Although it may not seem to be very exciting (and no one really cares to hear about this part) it is very nice, just insert cardboard or paper into the machine and get perfectly fitting boxes and sleeves (or circular labels). I of course spent a bit of time designing these but now I can make many without too much trouble.
The final step is to check that each piece fits into their respective slots and into the board. I fix any minor problems with more gentle sanding, and touching up with stain if required.
I think I am now done with the flat-pack type travel chess sets. I like this set more than the pixelated set. I may make another chess set in the future but the next project I am working on is more mechanical with several gears and other moving bits, stay tuned to see how it turns out…