Gears & worms

The gear train for screw cutting is quite different to most other lathes in that it utilises a worm. 17 gears & 3 worms are supplied for the B2

On the top left are the three standard and one special worm used for screwcutting and other machining operations. Three of these were supplied with every lathe, a one start, a five start and a 10 start. The largest one is a non standard 15 start worm which would have been a special order.

For my Pittler B2 the set with number 1253 comprises 18 gears.

20,22,24,26,28,30,32,34,36,38,40,48,50,60,80 for multi start.

30,50,80 for single start,

On the left shows the mandrel fitted with a 5 start worm engaging with a gear fitted on the screw cutting spindle which is shown on the photo below it . The spindle passes through the reversing gearbox.

Above: part of a non standard set of wheels with a much coarser pitch. Although these are clearly for the B2, and they fit the mandrel on both my B2 lathes, the gears are too course to engage with my other gears. The pitch of these is 25 (2) 30, 35,40,45 and a 20 start worm shown below left. Apart from the 30 & 40 these are also non standard pitches.