The crosshead and slide bar are straightforward jobs on the milling machine and shaper. Only some care is needed to work to close tolerances, so they have a nice sliding fit.
The cylinder covers are turned from brass bar. This is fine, although bronze would be better of course. The glands, however, will be made of bronze.
My small roller‑bearing tool is very useful for ‘straightening’ the thin disk in the chuck before turning the other side. With the chuck running slowly, the bearing is pressed against the cylinder cover, pushing the part back into the jaws until it runs true. After that, the chuck can be tightened securely.
Machining the rear cover on the rotary table to ensure accurate bolt‑circle spacing and a perfectly concentric profile.
Tapping M3 for the slide bars.
A small recess was machined on the back side to provide wide access to the steam ports, ensuring an unrestricted steam flow.
The slide bars are made from 5 mm thick cold‑drawn steel. Only the width has to be reduced to 14 mm. With a tolerance of −0.02 mm, measurements with the micrometer are essential, before taking the final light finishing cut.
The oil holes are drilled with a 1 mm drill. Their positions are taken from a photo of the original locomotive.
This is the real engine as it appeared in 2005, still in its black livery with red inner frames. The GER version had yellow inner frames.
II wanted to use cast iron for the crosshead, but I didn’t have any suitable material in stock. What I did have was an old brake shoe from a German BR23, bought many years ago at the Hermeskeil Dampflokmuseum.
It had been lying around ever since, so I decided to cut it up to provide a source of cast iron — recycling it into a new part for this model steam locomotive.😃
Cast iron slides well on steel, has a low tendency to seize under poor lubrication, and is a fine material to machine. But starting with a brake shoe is quite a job, as the raw casting needs a lot of preparation before any accurate machining can begin.
The shaper was put to use to square up a block from the off‑cut.
I have no idea why this piece of steel was cast in; perhaps it served as a wear insert or reinforcement, but it’s impossible for me to tell for sure.
Final shaping was done on the milling machine in several steps.
A first test fit on the slide bars went perfectly, with a smooth, even movement along the full travel.
The M2 thread was carefully drilled and tapped, taking light pressure to avoid breaking the small tap.
The top cover plate was also made from the same cast iron.
A small lid on top of the oil reservoir was made from steel bar.
With four small rivets (glued in with Loctite), the top cover was secured.
The same locomotive in 2022, restored to its correct GER livery, complete with yellow inner frames.