Recover the Leinen lathe original look

March 15, 2013 in machine overhauling, boley leinen LZ4SB

An important task during the Leinen lathe refurbishing is to recover it’s original aesthetics. This a time consuming process if you want a quality result. These are the main tasks:

Clean and remove rust of surfaces
Polish the surfaces
Prepare the surfaces to be painted
Paint

Lathe tools tray

December 31, 2012 in machine overhauling, boley leinen LZ4SB

The factory pictures of the lathe show a tool tray and stand for the blueprints. We made a tray identical to the original. The work of steel sheet, for which we have no material or tools, was made by Lázaro Metalpress. The result, once painted is this: The tray was covered by a neoprene sheet of Plàstics Pujol.

New electrical wiring

December 31, 2012 in machine overhauling, boley leinen LZ4SB

Altivar 312The lathe comes with an classical electromechanical wiring. It has an original Bauknecht 2 Kw and 3 speeds motor (720, 1450, 2880 rpm) . It was originally a 3 phase 220 V motor that in some moment was rewound to 380V. It has two speeds in a dahlander winding and an additional speed in an ordinary winding. Note how big and sturdy is the motor enclosure because of the number of speeds:

Review the two speed reduction gearbox

December 26, 2012 in machine overhauling, boley leinen LZ4SB

The Leinen lathe comes with a two speed 1:1/1:8 reduction gearbox that can be operated while the machine is running. It works by using a multiple disks oil bath clutch. We disassembled the gearbox to check its condition. The reduction has a very thick deposit of oil after years without maintenance. Disks are in good condition and shaft seals are a bit worn. The following image shows the reduction set of parts after unassembling it.

Repair the compound rest of the Leinen LZ4SB

December 19, 2012 in machine overhauling, boley leinen LZ4SB

After being adjusted, the compound rest shows two issues: The motion screw exhibits a play that cannot be decreased. Provably the adjustable nut is severely worn. The crank has a fixed friction point when turning. No hints about the causes. The compound rest has been dismantled and thoughtfully cleaned. First it was necessary to make a special socket wrench for the adjusting nuts of the compound gib. Next picture shows the wrench.

Overhauling the tailstock

September 16, 2012 in machine overhauling, boley leinen LZ4SB

Let’s start by restoring the tailstock, which seems to be in pretty good condition. Tailstock is unusual since it is designed in such a way that the barrel remains fully supported despite its position. It’s a typical construction of some precision machines. The tailstock is fixed to the bed using a lever that acts on a cam lock. The spindle is locked by classic crescents. The fit of the barrel is very good, especially in the first part of the displacement.

Finding the lathe manuals

September 15, 2012 in machine overhauling, boley leinen LZ4SB

The lathe arrived, as usual, without any kind of documentation. In some pages on the net there are partial copies of documentation of similar models.

First impressions

September 15, 2012 in machine overhauling, boley leinen LZ4SB

The first impresions just after the machine arrived:

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