With pre-WW2 origins as the Model L4Z, by the 1950s two models of this very serious-quality toolroom lathe were available, the MLZ4S and LZ4S. By the 1960s, although these lathes were commonly advertised with the maker’s name “Boley Leinen”, each model had the word “Leinen” before its type descriptor. The MLZ4S was fitted with a “Multiplicator” screwcutting gearbox where, by rotating three knobs (or levers on earlier examples) 27 different metric screwcutting pitches from 0.1 to 6 mm were produced as well as 35 longitudinal feeds from 0.017 to 1.16 mm per rev.). The LZ4S was a less expensive model that used changewheels and a simple feed box to give 6 sliding and surfacing feeds for each setting of the changewheels whilst for lathes not intended for screwcutting a even cheaper two-stage belt drive could be fitted to power the feeds’ box. On both machines the spindle bore was 0.98 inches with spindle drive pulley (a very wide one to take a smooth-running flat belt) arranged, as on all similar high-class lathes, to run in its own bearings and drove the spindle through a peg, so removing any chance of the drive belt’s pull transmitting vibration or spoiling the machine’s accuracy.

Built in April 1960, modified to a 2.2 kw 3 phase motor and inverter.

Fitting a cheap secondhand set off Heidenhain digital readout linear scales to an old lathe.

Let’s first see if the Internet-bought Heidenhain digital readout kit for my lathe works.
Fortunately, it looks very promising.

Mounting the first glass ruler
On an old lathe there is usually no space for the Heidenhain digital rulers . So being creative with your space during the conversion is  important. Mout the glass rulers as close as possible to the lathe. This saves a lot of work, and will benefit accuracy.

The first axis is fully assembled, and works well. The measured values ​​are consistently lucky. So everything is working fine.

As the second glass ruler is not connected there is an error on the screen …

The protective cover mounted … and the first axis is ready.

Mounting the second glass ruler
The assembly of the second glass ruler is more difficult. There are not enough mount points available. I will therefore have to drill in the lathe.

I have some experience in adapting metalworking machinery. And I now know that old German steel is a lot harder – and better – than that Chinese junk they sell nowadays.  But I have made ​​it!

And then it’s quickly on the cover ….

And then  attaching the Heidenhain digital readout linear scales to my old lathe is finely ready!