The first time I saw a CNC router, my mind started racing with all the possibilities of things you could do with it. Putting a pen plotter onto a CNC machine is nothing new, but I wanted to make one that was compatible with the ShopBot at TechShop.
With a Sharpie plotter like this, you can draw on many different types of surfaces--paper, cardboard, fabric, acrylic, wood, and metal. I'd like to make another one that supports a whiteboard marker next! That way, you can put a whiteboard down on your machine, draw something incredible, and hang it back up on the wall!
I made this at TechShop.
Step 1: Build Process
For this project, I just needed about 8" of 1" round aluminum.
All of the work is done on the metal lathe. First, I turned it just to make sure it was perfectly round. Then I came in with the tailstock to bore out the inside. Using center drills, start a hole. Then, make your way progressively up to a half inch. Make it at least 4" deep. This will be wide and long enough for the marker to fit.
Now, replace the chuck in your tailstock with a live center. Bring it in to support the piece for the next operations.
At the same end, turn the material down to exactly 3/4" for about 1/2" from the end.
At the other end closest to the head stock, turn the material down to exactly 1/2". Use calipers to check your diameter. This is what will fit into the collet on your machine, so it must be nice and snug.
Optionally, you can add knurling. Because I went with a friction fit between the two pieces, I wanted something that I could grip to make it easier to put on or take off.
The second piece is just a cap that fits onto it to hold the Sharpie in place. Because a Sharpie has a little lip, the trick is to make the diameter of the hole inside the cap, slightly smaller (7/16"). Once that's drilled all the way through, come in with a 3/4" bit and only go half way through. The top piece will friction fit into it and will stay secured, holding the marker from falling out.