My CNC upgrade project is progressing quite well. All axes are now up and running, most of the mechanical upgrade works are done, so it is time for a test ride. I didn't immediately wanted to start with milling just to test accuracy, so I decided to use the good old cheap and very clean pen method, which simply means that instead of milling real material place a pen on the Z and use that, not the spindle motor. Basically, this converts the CNC into an old flat bed plotter, except that it can't read HPGL files, which is the most common file type for plotters.
I created a G-code pattern manually and tried it out with an ordinary permanent marker pen. Of course, the results were not so pleasing. Not because there was anything wrong with my CNC, but it isn't really possible to use a pen instead of a spindle, at least not this way, by simply fixing the pen on the spindle holder.
The pen holder looks like this when installed on the spindle holder:
Attachment 314028
The results after running the G-code are very good.
Attachment 314030
I run the same drawing four times on the same sheet and you can't really see that it has been run four times. I am very pleased with the results so far.
Visit my blog post if you are interested in details and want to see many illustrative images about how I made this pen holder. The link to my blog post is this one:
Adapting Camera: Making a pen holder for my CNC
Good luck if you decide to use my idea and make a similar pen holder.
I made a video also but have no time to process and post it right now. Will get back and post it when I am ready with it.