Stainz on Rolling Test Stand

This documentation describes the retrofit of an old LGB locomotive from analog to CTC. Specifically, two Stainz models (2020 and 2021) were retrofitted. For this, I (Peter Rudolph) met with our customer Gregor Denndörfer via video conference, and we retrofitted my 2020 and his 2021. At this point, many thanks to him for the images of the 2021.

Important: This documentation was created before our decision regarding cable colors. The cable colors in the photos do not correspond to this decision!

For these small LGB locomotives, we still don’t need special garden railway modules. The CTC-Locomodule-H0a is completely sufficient.

With the old LGB locomotives, there is the fundamental problem that at least one pole of the motor is permanently connected to the power pickup in the motor block. This was also the case with ours.

First, the locomotive must be dismantled enough to access the motor block to open it. How to dismantle a Stainz is well documented on the internet. Unfortunately, there are also many versions of the Stainz, which left us guessing until we actually had the motor block in front of us:

Retrofit Stainz - Motor Block Removed

This is what the motor block of the 2021 looks like:

Retrofit Stainz 2021 - Motor Block Removed

The following links helped us:

These were the essential insights:

  • The cab and boiler are mounted in the middle of the frame from below and can only be removed after the motor block is removed.
  • The motor block is very tight. It can be taken out after the chimney is unscrewed, both couplings are removed, and the linkage in front of the cab is unscrewed and unhooked.

For the 2020, the linkage had to be removed and one side of the wheels taken off to open the motor block, which consists of two half-shells:

Retrofit Stainz - Motor Block Open

For the 2021, the motor block has a top and bottom cover, so the linkage does not need to be removed.

Retrofit Stainz 2021 - Motor Block Open

In the 2020, the motor contacts are made of metal strips in the two half-shells. These were broken off by bending back and forth. In the following image, I’ve already removed the metal strip from the lower half-shell and just started bending it in the upper one:

Retrofit Stainz - Removing Motor Contacts

In the 2021, the motor contacts are thick brass pins, and only one side was connected to the power pickup. Here, just enough of the brass pins was removed so they still held but couldn’t make a connection to the motor anymore.

Retrofit Stainz 2021 - Removing Motor Contacts

Now, cables were soldered to the contact pins in both variants (the motor itself is identical). Then, holes were drilled for the cable routing up into the housing. It is important to ensure that these come out at a point where they won’t be pinched during reassembly. The following image shows the 2020 again:

Retrofit Stainz - Cables Soldered to Motor

And here is the 2021:

Retrofit Stainz 2021 - Cables Soldered to Motor

In the following reassembly, for the 2020, it is important to ensure that the pins on the wheels run synchronously. It is best to test whether the wheels can still turn with the lowest rod. I had to take my motor block apart twice more until the linkage ran correctly.

Since the power connection from metal strips to screws in the base plate did not convince me, I also soldered cables here:

Retrofit Stainz - Cables on Motor Block

At the latest, now you should check whether the motor still runs and all track contacts work.

Now the motor block could be reinserted into the base plate and the CTC-Locomodule-H0a connected. We consciously omitted the screw in the middle of the housing and boiler.

Retrofit Stainz - CTC Module Connected

In the following image, all cables are already connected to the CTC module:

Retrofit Stainz - CTC Completely Wired

The last challenge was to place the wiring in such a way that nothing would be pinched during reassembly. For this, I trimmed a bit of the boiler panel in the cab at the bottom and partly fixed the cables with a hot glue gun:

Retrofit Stainz - Cables Fixed

I placed the CTC module in the water tank on the right in front of the cab. When reassembling the housing, I removed the cover of the water tank and pulled the CTC module up to prevent pinching the cables.

After 8 hours of retrofitting, it was finally done: The introductory image of this article shows the finished retrofitted and CTC functioning Stainz on the rolling test stand. If you look closely into the cab, you can see the support capacitor that originally should have gone into the coal container. Unfortunately, I made the cables a bit too short, and it was already late in the evening—maybe I’ll fix it another time?!