This was inspired by https://www.instructables.com/id/Super-Easy-Custom-Rubber-Stamps/ and https://www.instructables.com/id/Block-Printing-With-Things-You-Can-Find-In-The-Tra/
I urge you to check those instructables first!
Step 1: Gather Your Materials
1x Mechanical Pencil with removable thin aluminum tube
1x Rubber Eraser (You can get them cheap at 99 cents stores. Mine were 5 erasers for $1)
1x Needle nose pliers, or similar multi-tool of your choice.
Step 2: Disassemble Your Pencil
These were the steps I had to take for this particular pencil.
1. Unscrew the head of your pencil (Pic. 2).
2. Slide out anything else, such as the gripper (Pic. 3 & 4).
3. Slide out the aluminum tube (Pic. 5 & 6).
4. Reassemble the pencil without the tube, and it still works like a charm (Pic. 7)
Step 3: Shaping Your Tool
Note the widths.
If you would like to stop here, you can and create your stamps. The thinner end will be for more detailed parts, and the broader end is to remove "meat" chunks. Big chunks of eraser with no intricate details.
You can go one step further, and finely shape your tool.
Step 4: Finely Shaping Your Tool
This is to further enhance the details you can create with your tool.
1. Grab the thinner tip of the the tool horizontally (Pic. 1).
2. Squeeze until desired width is achieved (Pic. 2). Remember, the thinner, the finer lines you can create, and the smaller nooks you can remove in the stamp.
3. Grab the broader end with your pliers. Squeeze this end until your desired width (Pic. 3 & 4).
Picture 5 shows the finished tool. You can create a total of 4 different widths on just one tool!
Here are a few photos of my tools and a few stamps I have created.
Stamps you create will show up as reverse!
Be cautious, this can be a sharp tool so use with caution.