Harbor Freight Tools 44859 Lathe User Manual


 
Page 8
SKU 44859
The Fixed Shaft Bolt (825) under the spindle is used for right hand cutting and threading.
The set of Fixed Shaft Bolts in the accessory kit is used in combination with the original set
of Shaft Bolts to reverse the rotation of the long leadscrew for left-handed threading and
cutting.
The change gear for metric or inch threading is selected according to the Thread to Gear
formula and table. The feed amount depends on the material to be cut, the surface rough-
ness, and finish requirements. If the two settings “0.1 and 0.2”, of the Gear table do not
meet the requirement, you can add or change gears. The same is true if the number of
teeth listed in the Gear table do not coincide with the calculated number of teeth. In this
case, use gears with similar number of teeth. In doing so, however, the following relation-
ship of the driving shaft must be met: Z
3
+Z
4
+>Z
2
+Z
5
. Otherwise, the addendum of circles A
2
and Z
5
will hit each other.
The left formula below is an example of 0.3 mm spindle round. The right formula is an ex-
ample for 8 threads per inch.
The Thread to Gear settings table on the following page allows you to select the number of
threads per inch or millimeter, and which gears need to be used.