Pen and Pencil Holders


The CNC machines can be used as basic plotters. The idea is straightforward, but for something so simple, it is surprising how annoying the process can be.

A pen does not fit in a router collet, and wiring or taping the pen to the Z axis does not provide enough support.

Copper fitting pen holders
Plotter pen holders.

These units were put together to remedy this.
The first ones are made of copper fittings and pipe, and are designed to use plotter pins.
Plotter pens are going extinct but are still available on EBay. I bought a discounted box of remnants from a local supplier who was glad to clear the inventory.

The middle and right holders were made from copper 3/8 inch male adapters. A male adapter is shown in the upper right of the photo.

An old router bit and Dremel bit were soldered to the ends of the adapters. Screws were tapped into the right adapter so it could hold smaller pens.
Larger pens friction fit in the adapter. For appearance, the male adapters were filed-ground-sanded while being turned by a drill to remove the threads.

The unit on the left is made of a ½ inch copper cap and a coupler, which are butt joint soldered. A section of ½ inch pipe slides inside the coupler, and a spring adds tension.
A slot is drilled into the sliding section of pipe that matches a screw in the side of the pipe cap. This screw prevents the pipe from falling out when the axis is raised.

The spring loaded holder is the most forgiving to use, but the others are simpler to make.
 
CNC pencil holderCNC Pencil Holder
Wooden pen holder.
Next is a pencil holder made of a 1¾ x 1½ x ¾ inch block of wood that is drilled as shown.

One hole is at an angle so the pencil's point will align with the center of the router's collet.
The shaft that inserts into the collet is a piece of ¼ inch stock that is cut from a bolt or rod.

After the holes for the screws, pencil and rod are drilled, the unit is cut in half.

The #8 machine screws clamp the unit together, and hold the pencil and shaft in place.
 
CNC pencil holder made from a compass
Pencil holder cut from compass.
Another option is made by cutting the pen holding leg off of an inexpensive compass.

The stump is filed to fit in the router's collet.

Now when trial runs are done, a pen or pencil can be put in the router's collet in place of a bit. These holders help to keep simple jobs simple.
 
The image below is of a model that used the CNC machine as a plotter. A pen was placed in the router's collet, and the print was drawn on foam board.

Model made with CNC plotter
Model plotted with CNC machine.
The model was then cut and assembled.
This process helped in the visualization of the gazebo/conservatory before the actual structure was built.

Gazebo-Conservatory
Finished gazebo.