Stand for Acrylic Side Lights – Movable Gantry CNC Machine 22

Aug02
by Thomas Yoon Chee Tuck on August 2, 2020 at 10:30 pm
Posted In: CNC

An important component of the acrylic side light was the base which houses the LED’s and the electrical connection. As the name suggests, the acrylic sheet with the carved design had to be held vertically at the base, and the light source had to be arranged to shine at the bottom so that their rays would penetrate the sheet from its bottom edge.

I happened to have a piece of LED strip and I intended to make use of it for the project. So my first attempt to design a base was centered around the dimensions and placement of the LED strip. Later on, when I started to engrave more and more 2.5D images on acrylic sheets for side lights, I began to use cylindrical shaped LED’s. Subsequently, the base that I produce was designed around those LED’s.

Since I could easily work on wood, I used my movable gantry cnc machine to machine out the pockets that I would place the LED’s, resistors, wiring, and electrical connection socket.

After the machining was done, I would arrange the components and solder them in place. The base would be finished off by coating it with a few layers of wood varnish.

The video shows the attempts I made to accommodate the LED strip and then later another attempt to redesign so that I could use cylindrical LED’s. My preference was to use the cylindrical LED’s for my future projects.



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2.5D Engraving for Acrylic Side Light – Movable Gantry CNC Machine 21

Jul02
by Thomas Yoon Chee Tuck on July 2, 2020 at 10:27 pm
Posted In: CNC

I had been quite successful doing single depth of cut engraving for some time now. Now I was looking for new capabilities. I had previously cut some 2.5D graphics on wood or phenolic boards. It was during one of these milling sessions that I found that my movable gantry cnc machine was not precise enough. Round objects turned out to be ellipse shaped when the milling was completed.

After many attempts at rectifying the problems and gradually making improvements, the movable gantry cnc machine was able to give quite satisfying results. So I was ready to try 2.5D engraving again, this time with the intention of making acrylic side lamps.

As I did not have any acrylic sheet with me then, my first attempt at milling a 2.5D image was done using a transparent piece of CD. This was actually my experiment with using the image-to-gcode feature in LinuxCNC, trying to figure out what the settings should be and how to get them right.

I found the result of the milling of a galloping horse was surprisingly good although the engraving was extremely small. It had to be small in order to fit into the space available in the transparent polycarbonate CD. Then I tried to do the same 2.5D engraving of a galloping horse on a slightly larger piece of transparent plastic to try out how to generate a larger image g-code. This time, the acrylic that I had available was in the form of the cover of a CD box. Again, I was able to experiment with the settings available and learned from the exercise.

Finally I was ready to attempt the cutting on a real piece of acrylic sheet. I bought a piece of 2mm thick casted acrylic for this purpose. Naturally, my image would be enlarged to fit the size of the acrylic. I tried out the gcode generation on LinuxCNC and I cut the 2.5D image using a 60 degree conical bit. With this bit, the image consisted of many closely spaced lines.

Later, I bought a round end mill bit and the lines tend to merge better resulting in a better image.

Encouraged by the good results of the galloping horse image, I decided to do another 2.5D image, this time a Dragon and Phoenix image on a larger piece of acrylic. The results were very good.



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