in this Instructable I'd like to show you how to make a mechanical pencil that's super small, can fit on you key-chain and you can take with you where ever you go. I designed this so that it can telescope into a larger pencil making it easier to use. When the pencil is in it's reduced size then it's barely noticeable and is only about three inches (7.5 cm) long. There are several different versions I've designed to fit your needs, but I will explain more about that later.
Hope you enjoy!
Step 1: Components and Tools Needed
To make this, all you need is:
1)Access to a 3d printer (or Shapeways)*
2)A simple mechanical pencil, I used a "studio (0.7mm)" pencil but I know many other will work also.
3) Possibly sand paper
4) You may need some super glue
*note: Since the tolerance and preciseness of all 3d printers are different, minor scaling and/or sanding may be needed.
Step 2: 3d-Print the Parts
I've designed three different types of pencils to suit your needs. The first version is the smaller of the three and consists of four 3d printed parts. The second version is a little bit larger and is made also with four 3d printed parts but it's a bit longer. And finally the third pencil needs five parts and is a lot larger. Download one set of the following files for whichever pencil you want to make.
To print pencil number one print 1 "top peice" 1 "original plug chg", 1 "top original" and 1 "bottom original"
To print pencil number two print 1 "top peice", 1 "original plug chg", 1 "bottom long" and 1 "bottom original"
To print pencil number three print 1 "top original", 1 "big plug chg", 1 "fat third bottom", 1 "top piece" and 1 "bottom lip"
Step 3: Prepare the Pencil
Once you've 3d printed or ordered the parts, you need to prepare the mechanical pencil. First unscrew the cap and let the white part fall out of the main body. Then cut the white piece as shown in the pictures for you specific pencil. Then slide the white part into the smallest piece of the 3d printed body, it shouldn't go in all the way . And finally slide the other pieces of your pencil on top of that and place the cap and plug on the top and bottom. The cap will probably need glue but the bottom should snugly (Eventually we need to take it off anyway).
Step 4: Your Good to Go!
Once you've assembled the parts and glued on the cap take off the plug and put some 0.7 graphite down the tube on the inside. Now just telescope into the smallest size and hold it upside down. Then "pump" in till the graphite comes out the top. If nothing happens then you've built it wrong, and just try to adjust the cap until it works. Now everything's done, now just attach it to your key chain or throw it in your bag the next time your going somewhere and you will never be in need of pencil again!