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Model Engineering Glossary: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Change Gears

Gears that link the main spindle of the lathe to the saddle longitudinal drive screw thus allowing threads to be cut.

The gears shown here on a Hobbymat MD65.

The spindle is driven with a belt and pulley system with an intermediate reduction pulley that can be seen on the left hand side of the image.

A gear is located on the spindle (behind the pulley in this image) and this has a key to locate it on the main shaft.

The set of gears here have a large reduction as the system is set up for a fine traverse.

The pillar at the bottom of the image has a lever that operates the dog-clutch to engage and disengage the leadscrew.

In this image you can clearly see the drivetrain.

With change gears there is quite a lot of setting up of the gears and care needed to get it right.

The middle intermediate pair of gears have a metal carrier that is also the bearing. This is adjusted on the aluminium plate that in turn can be moved get the correct engagement of the gears on the main spindle.

As these are plastic gears I have left them dry, but they do pick up quite a lot of dust from the workshop, to date this has not done any serious damage and these gears have been used for around 30 years, ok fairly light use.

A box of spare gears used to create the other spindle to leadscrew relationships.

See also: Lathes.

Model Engineering Glossary: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z