User manual

Settings and adjustments

Your microlathe has been factory set and adjusted, however, during its life time

you may find occasion whereby the lathe needs adjusting to maintain its accuracy and

optimum performance. These adjustments can be made as follows:-

Saddle and Traverse slide adjustment

The saddle and the traverse slide are both mounted over dovetail sections. In order to maintain

the ‘tightness’ of the fit; between the sloping surface of the component and its mating surface a

gybe strip has been inserted. (At the rear of the saddle, and to the right hand side of the traverse

slide).

To adjust the gybe strips, loosen the lock nuts and screw the adjusting screws IN, (4 No. for the

traverse slide and 3 No. for the saddle). ‘nipping’ the component tight to its bedway. Tighten all

the screws to the same torque. Check, using the feed handles, that the saddle/slide are locked in

place.

Unscrew each adjusting screw by a quarter turn, hold the screw (socket grubscrew) in position

and tighten the locknut. Check the component now moves smoothly along its bed, using the feed

handles. If not, carry out the same procedure, unscrew by a third turn this time, etc, if the

movement was too tight; by less than a quarter etc., if the movement became too loose.

Repeat the procedure until the movements are smooth and tight. N.B. Always tighten the locknuts

before testing.

Feed scales

The two thimbles that are mounted on the feed shafts of the leadscrew and the traverse feed

should move freely with the motion of the handle and not slip. The thimbles can be turned, using

more force, independently of the handle in order to set a predetermined start or finish point. If the

thimbles are ‘slipping’ i.e. not maintaining their place relative to the handle, whilst the handle is

turning; the cause is almost inevitably dirt, swarf et al., between the pressure plate and the

thimble. To rectify this, undo the nut and washer securing the handle to the shaft, remove the

hand wheel, and then remove the keyed collar and thimble assembly. Take care that the key does

not drop out of the shaft. Gradually separate the thimble from the keyed collar, by twisting and

turning, until there is sufficient space to clean the mating surfaces.

BE WARNED The friction drive between the collar and the thimble is effected by a

wire spring (like part of a circlip) that is housed in a groove in the collar and rubs against

the inside bore of the thimble. If the collar and the thimble are separated too far, the

groove and the spring are exposed. The spring can fall out and if not lost, it is awkward

to re-compress the spring so that the thimble will slide completely back onto the collar.

Once the mating surfaces are clean, mate the key and the keyway and fit the collar/thimble

assembly to the shaft. Refit the washer and the securing nut, and tighten. Tighten until the

handwheel, thimble and collar assembly are too tight to move. Undo the securing nut a quarter

turn and check the that the drive handle rotates freely and there is not excessive backward and

forward play in the shaft. (The handle etc, forms one side of the drive screw anchor into the

slide).