Some people will have seen the laser etched blocks I produced as my first project with SM1. I was pleased with the results and determined to make a few sets of kids toys with alphabet blocks. I also experimented with colour but it proved more difficult to solve the issues thrown up with non-toxic paint finished for young children. In the end I found a non-toxic poster paint but was not happy with the overall result. The image below might be informative…
The wood is pine and I had not realised just how difficult it would be for the laser to etch the much harder wood of the annular rings. In fact in many cases, the laser did not touch the harder wood even on 100% power for the 1600mW upgraded version.
I had idly wondered whether something in the paint was protecting the wood from the laser beam. It was a newbie’s stupid thought really as the next image is shown with plain blocks. Remembering how successfully I had engraved the first wooden blocks from exactly the same source.
The letter M on the left of the image shows the quality I was getting initially. the blocks inside the red ellipse show what the quality is like on the a few of the batch of 1200 blocks I had purchased. A complete newbie error made because I had no idea how much wood varied in its grain or hardness. If I work on the principle that the batch of blocks I purchased are all going to give me some sort of issue (these blocks were randomly selected from a box of 400 blocks) then a solution needs to be found.
I had thought about coating the blocks in some sort of acrylic paint that would smooth their surfaces while adding little to their overall dimensions. I rejected that on cost and toxicity for kids mouthing the blocks. In the final analysis I decided to try and carve the blocks using the CNC capabilities of SM1.
The major problem to overcome is how to hold the blocks stable and in the correct position for any carving operation to take place. I did not want blocks to shift while being carved nor did I want the cost or the inherent safety issues if the endmill would break at regular intervals. Liking the notion of a jig for the laser etching of the blocks, I decided to try and adapt it.
My idea is to use some form of quick release clamp system that would hold the block for carving and release it quickly for flipping faces and then retighten it to carve another face. It turns out that the sort of clamp system that I think I need to use is available commercially. I do not need to buy the whole system but just want to buy a few bits to enable me to make my own jig.
I am now in the process of assembling the necessary bits to make up a jig for carving the blocks. I will post the resulting images of the jig assembly process and the first carved blocks.