ON HORIZONTAL COUNTERSHAFT LATHES
TO REPLACE SPINDLE BELT:
1. Remove complete back gear assembly by unscrewing the four hex cap screws which hold back gear assembly to head.
2. Spindle pulley guard is attached to the back gear assembly. Remove guard after back gears have been removed from the lathe.
TO REPLACE BEARINGS OR GEARS:
3. After completing operation above, loosen set screw in collar A and remove collar.
4. Drive out groove pin R.
5. Slide back gears from shaft C.
ON VERTICAL COUNTERSHAFT LATHES
1. Remove the two guards that cover the spindle gears and back gears.
2. Remove complete countershaft bracket assembly from the lathe.
3. Remove complete back gear assembly by unscrewing the two hex cap screws which hold back gear assembly to head.
4. Loosen set screw in collar A and remove collar.
6. Slide back gears from shaft C.
(Necessary for replacing spindle belt or bearings)
1. On ATLAS 10" Vertical Countershaft Lathes remove the two guards which cover the spindle gears and back gears.
2. Loosen set screw in collar E and remove collar by turning anti-clockwise. Beneath set screw is a small thread protector, do not lose it when collar is removed.
3. Loosen set screws in collar F, and large spindle gear G.
4. Slide spindle gear H from spindle. If gear sticks, tap lightly with a piece of wood and a hammer.
5. Remove key K from spindle with a pair of pliers. Slide flanged collar J off spindle.
6. Wedge two pieces of wood between head and large spindle gear G on both sides of spindle.
7. Place a piece of wood against left end of spindle and drive it in direction indicated by arrow until key L emerges from large spindle gear G.
8. Remove the wood wedges and remove key L with a pair of pliers.
9. Drive spindle entirely out of headstock in direction of arrow. BE SURE TO CATCH THE SPINDLE AS IT IS RELEASED FROM THE HEADSTOCK. It is not necessary to remove spindle entirely if replacing belt only.
10. To remove belt from countershaft loosen the (4) square head set screws which hold countershaft spindle in hanger and remove spindle assembly.
FIGURE 1. Sectional view of ATLAS 10" Timken Bearing headstock
1. Lightly file all burrs caused by set screws from spindle and back gear shaft.
2. Clean all parts thoroughly including Timken Bearings.
3. To reassemble, reverse the above procedure. Be sure belt is in position. When driving spindle into headstock, use the palm of your hand as much as possible to avoid damaging the precision surfaces of the spindle nose. Use Figure 1 as a guide, making sure all parts are installed in their proper positions. Read the following instructions for spindle and back gear adjustments.
1. Slide collar F against shou1der of spindle and lock in place. Move pulley-gear assembly against collar and slide large spindle gear G against pulley and tighten set screw in gear. There should be a slight amount of clearance between the pulley and the large spindle gear to permit pulley to turn freely.
2. Tighten collar E until all lateral (end) and radial (side) play has been removed from spindle. Check by tapping spindle back and forth with the hand. Do not tighten spindle too tightly -- spindle should rotate freely.
3. Pre-load spindle bearings by continuing to tighten the threaded collar E approximately 1/16" turn (equivalent to two spindle gear teeth). There should be a slight drag felt as the spindle is rotated by hand. This is important because as spindle and bearings warm up, the spindle expands laterally approximately .002". Tighten set screw in collar E.
1. Move collar A against crimped washer causing back gear assembly to fit snugly between the brackets. This will eliminate gears from jumping out of mesh when using back gears in lathe operations. Tighten set screw in collar.