CNC Router Demonstration 1: Engraving the P.COC Logo
You've got to be asking yourself, what is a P.COC logo? First of all, P.COC stands for Project for Complete Open CNC, and it also sounds like Peacock (the bird with beautiful feathers that open up, get it??). The graphical part of the logo uses a screw as the body of the bird and nuts to symbolize the feathers. My wife thinks it looks like the sun and I should lose the screw. The logo symbolizes the philosophy behind all that I do here, volunteer my time to show how to build a completely open source CNC routing machine. I have also designed a logo to be cut out on the CNC Router, and how cool would it be to initiate my demonstrations with that logo.
So, this first demonstration I will cut out the actual logo and the title. I first used AutoCAD to design the graphical part of the logo. I only have 5 more day of use with AutoCAD since it's the evaluation version. I will then be using Solid Edge 2D drafting system. With the logo complete, I saved the file in dxf format (an exchange format the works with most CAD applications). Also, most CAM applications will accept dxf format to interpret to g-code. I then take the dxf file and import it into LazyCAM. As I mentioned in a previous post, there are many programs that will convert the dxf to g-code, but there are pros and cons with each one. Ace converter will do a good job, but the tool paths are not efficient and if you want to save time in the cutting process, you will need to go into the g-cod and clean it up. LazyCAM is very user friendly and also contains a clean or optimize button to do some of the organizing of the toolpaths for you. LazyCAM also enables you to shuffle around the toolpaths if you don't like the order.
LazyCAM also enabled me to add text. I know what you're saying... why didn't I do the text in the CAD program? The text in CAD files are not in vector format. The full version of AutoCAD has an explode text tool in the express tools, but that comes with a hefty price tag. Alternatively, I could have constructed the text... yeah, I could probably construct the CNC machine in less time.
Then, it's just a matter of pressing the post g-code button in LazyCAM and Mach3 will have a ready-to-go file to start cutting. Yeah, there were many other operations I did in the middle of all that, but I will leave that for another post, just to keep a little suspense.
In the video, I prepare the router's collet with a tiny end mill. Unfortunately, the end mill has a 1/8" shank and my router's collet is 1/4". A shank is the cylindrical part of the bit that is inserted into the collet. The collet is the mechanism that holds the bit, using the shank. To make a 1/8" bit fit into a 1/4" collet, an adapter is needed. I show this in the beginning of the video. Then I show the cutting in action. I also seed up the video so I don't put you to sleep. Routers tend to have a hypnotic effect.