A CNC router owner can adapt their machine to become a pen plotter that can draw accurate designs on paper. While there are several ways to do this, ranging from buying individual pen bits to making your own adaptations (you’ll find an abundance of suggestions on the Internet), here are a few tips to help optimize your efforts while protecting your machine.
Allow For A Spring Mechanism

One of the most common difficulties router owners have when turning their CNC router into a pen plotter is that the pen makes inconsistent marks on the paper. This is commonly due to irregularities in the shape, grain, and depth of the paper itself. When we draw by hand, we naturally compensate for these irregularities without thinking about it by applying more or less pressure to the pen, but CNC routers operate with such rigid accuracy that the pen does not move up or down with the paper. To solve this problem, you want some sort of spring mechanism in place that allows the tip of the pen to shift up or down slightly with the paper. This can be a spring mechanism within the pen itself or a spring located within whatever adapter you buy or build.
Keep Modifications Contained To The Adapter
When using your CNC router as a pen plotter, you’re essentially modifying the machine to accomplish a slightly different task than what it was built to do. This is fine and won’t harm the machine, as long as you keep your modifications contained in the adapter or attachment itself. If you make significant changes to the machine itself that extend beyond its design, you run the risk of causing damage to the machine and possibly voiding any warranties—not to mention endangering yourself. There are plenty of solutions that work, from specialized pens to custom-built attachments. Keep your modifications contained to this area, and you’ll keep your CNC router safe.
CAMaster is committed to helping you use your CNC router successfully in a wide range of applications. For more advice on adapting your CNC router or any other needs, contact us.