Backlash adjustment, Cross slide, Compound rest – Southbend Gearhead w/ Dro SB10146PF User Manual

Page 79

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SERVICE

For Machines Mfg. Since 3/11

Turn-Nado

®

Gearhead Lathes

-77-

S E R V I C E

Cross Slide

Tools Needed:

Qty

Hex Wrench 3mm .................................................1

Hex Wrench 5mm ................................................1

The cross slide backlash is adjusted by loosening

all four cap screws shown in Figure 112, then

tightening the center set screw. This will push

down on a wedge and force the leadscrew nut

apart, taking up lash between the nut and

leadscrew.

Backlash Adjustment

Backlash is the amount of free play felt while

changing rotation directions with the handwheel.

This can be adjusted on the compound rest

and cross slide leadscrews. Before beginning

any adjustment, make sure that all associated

components have been cleaned and lubricated.

Compound Rest

Tools Needed:

Qty

Hex Wrench 3mm .................................................1

The compound rest backlash is adjusted by

tightening the set screws shown in Figure

111. When these screws are adjusted against

the leadscrew nut, they offset part of the nut to

remove play between the nut and leadscrew.

Figure 111. Compound rest backlash adjustment set

screws.

Set Screws

Reducing backlash to less than 0.002" is

impractical and can lead to accelerated wear

of the wedge, nut, and leadscrew. Avoid the

temptation to overtighten the backlash set

screw while adjusting.

To adjust the backlash, rock the handwheel back

and forth, and tighten the screws slowly until

the backlash is approximately 0.002"–0.003", as

indicated on the graduated dial.

If you end up adjusting the nut too tight, loosen

the set screws, tap the compound rest a few

times with a rubber or wooden mallet, and turn

the handwheel slowly back and forth until it

moves freely—then try again.

To adjust the backlash, remove the compound

rest and loosen the four cap screws. Then, rock

the cross slide handwheel back and forth, and

tighten the set screw slowly until the backlash is

at approximately 0.002"–0.003" as indicated on

the graduated dial.

If you end up adjusting the nut too tight, loosen

the set screw, tap the cross slide a few times

with a rubber or wooden mallet, and turn the

handwheel slowly back and forth, until the

handle turns freely—then try again.

Remember to re-tighten the four cap screws

when you are finished.

Figure 112. Cross slide backlash adjustment screws.

Set

Screw

Cap Screws

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