This instructables describes and shows how to build a simple gear puller.
If you like to tinker with motors you'll find that a lot of motors from toys and equipment have stubborn pinion gears stuck on the shafts. These can be a pain to remove, and while prying on them or punching them out with a hammer can sometimes work, you risk damaging the motor.
This will show you how to make a very effective gear puller with basic tools and next to no cost.
Step 1: Cutting the frame
You will need something to act as the frame for the puller. Square metal tubing works great for this as long as the wall is thick enough to tap threads.
I used a piece of 1" square steel tubing with 0.1" wall thickness. I cut it to a length of 0.75" with a hacksaw, it doesn't have to be pretty.