Hi All,

I read Costas article with interest and very much liked the detail that Costas went to for his locomotive upgrade.

Costas Article

I thought I should include how I did the conversions using a different decoder, a LokPilot V4.0 and adding LED lights.

Ross' Article

The notable difference between the two conversion methods is I didn't have to alter the magnet from the 60941 motor kit.
The Relex couplers were upgraded to close couplers for better double heading running.
I had planned to add cabin lights but because there are no interior details I didn't add the feature.
Costas red lights were a nice feature which I may revisit when I upgrade the decoders in my crocodiles in the near future.

I hope you enjoy the extra information on converting crocodile locomotives.

Edited by user 02 January 2025 00:47:49(UTC)  | Reason: Link corrected 02-01-2025

Hi Costas,

Thanks for your liking my documentation.

Your question is a good one re milling the magnet. I have done six crocodiles and haven't had to mill the magnet at all. The locos all run on R1 (360 R) curves in both directions without problems.
To confirm this I had a look at all my crocodiles to ensure I hadn't milled the magnets as these conversions were done some time ago.

All I can suggest is Märklin may have changed the tooling to improve the turning movement.

I do note that on your conversion the choke is very close to the milled area on the magnet (see Choke position 1) and some of the wires are in that area also which may restrict the turning movement. In the second photo (Choke position 2) the choke is mounted further away from the milled area, but since your locomotive runs well you have done enough milling to suit your case.


Choke position 1


Choke position 2

I also note that you have used Märklin wires which are thicker where I have used ESU wires that are thinner so this may also contribute to less space for movement.

I think the bottom line here is if the movement is restricted look at things that may restrict movement, change the arrangement of components and as a last resort mill as little as possible to improve the turning movement.

Exactly! That is very good to know, especially since I now run only on C track.

Both threads have been a tremendous help to me as I finally get closer to having the time to start the upgrade project on my ancient 3056 Croc. Märklin is still selling models with this same motor today - think about that for a moment! But with a 5 pole commutator and modern electronics they run very well IMO and make excellent upgrade candidates.