Plastic Injection molding is simple with the right equipment. All that you need is a heater and some plastic.
Recycled plastics will yield the best results if kept to their respective groupings. Refer to the recycle symbols and do not mix types.
ABS is my plastic of choice, I used an old HP inkjet printer as the raw materials for this example.
I used a commercially available temperature control for this project but I have posted an accurate precision temperature controller in another Instructable.
All told this project took me about 2 hours and about $50 to assemble and test...
shown below is a 3mm ABS extrusion being done
NOTE: I have added a section with an example of a crude press lever.