This is a simple project that you can do with your pillar drill or drill press.
This pulley turned out quite nice.
It works best with mdf as it is really easy to work with it helps to have a sharp chisel and dust collection and mask is recommended. You could create any size your drill can take,and use different thickness MDF for different widths of pulley you might be able to glue a stack together and create a wider one or even a step pulley but maybe bolts or nails would be needed to keep them together.
Step 1: Cutting a Disc
A circle is cut out using a hole saw.
A hole larger than the hole saw pilot hole is made for the bolt.
Step 2: Setup
A bolt is then popped through the hole with a nut on the other side
Tightening the bolt to almost 'nip' the wheel.
You can also thread the wheel so that you don't have to tighten it so much.
chuck the bolt into the pillar drill/drill press.
Set up another bolt attached to the table.you could also clamp a piece of wood down.
Step 3: True Everything Up
True everything up ,you could also cut out a circle using a router or jigsaw and then true it up.
Step 4: Create Your Pulley
Then with a small chisel start to take out the 'middle' material
until you have reached the width and depth of you pulley.
Then sand down with 180 to about 400 or so doesn't need to be that smooth.