Small gears are used as parts of an engine or motor for a multitude of smaller items. Clockwork toys, small toys and music boxes are a few kinds of toys that have small gears moving inside that are easily broken. It is wise to have the ability to create replacement gears when such problems occur. The process of making a small gear can be easily done with the proper tools and careful practice. However, the need for precise cutting makes the process difficult for someone without experience with a lathe.
Things You'll Need
- Bronze blank bar
- Metal marker
- Scroll saw
- Drill and bits
Measure the original gear for width, diameter and teeth length using a ruler. Cut a bronze blank bar with a scroll saw to the thickness of the gear needing replacement.
Set the gear needing replacement on the top of the blank bar. Mark the outside of the gear with a permanent marker, making sure to clearly mark inside the teeth. Use the scroll saw to cut the blank bar around the marking. This will create a circle the size of the gear needing replacement.
Lock the bronze circle into the lathe holding fixture. Place the cutter bit that fits between the original gear's teeth into the lathe by checking the tooth size.
Cut the grooves into the bronze blank following the markings on the blank using the cutter bit.
Cut a hole into the middle of the new gear with a drill and a bit. Check the size of the bit with the original hole in the first gear.