Hello,
an old project, but maybe interesting. I bought an Märklin 3352 Crocodile, used and allready equipped from the former owner with an Esu LokPilot 3 M4. The model looks like new, but I liked to change the motor to HLA 5-pole and ball bearing:



Here You see the ball bearing of the gear box:


The original bearing is the plastik bearing. It can be removed very easily by pressing from the outer side to inward. The drilling hole diameter is 4.0mm. Therefore, You can use a standard miniatur ball bearing 4.0x1.5x2 (681ZZ) and just press it into the hole. Sometimes, it is easier to press it from inner side instead of from outer side.



Then I changed the Esu permanent magnet to the HLAmagnet with 5-pole and new motor shield:



The HLA permanent magnet must be modified, otherwise it would have a conflict with the case and the crocodile would not operate with 360mm radius. Therefore, I grind down a chamfer as seen in the picture below. Abit more could have been better, but this is just enough:



The ball bearing for the motor shield is the same size as for the gear box. For this, the motor shield must be drilled very carefully and centrically from 1.5mm to 4mm (some people drill only 3.9mm). I use a center drill (2mm-4.0mm).



With CV53=20 the Vmin is 2,4km/h, a very nice value for smooth driving:

Edited by user 23 April 2014 09:34:46(UTC)  | Reason: Not specified