Tram only runs one way :(

[Aleks]

I wonder if anyone may have had something similar. A few months ago I got this Kato Lemke Duwag M6 Bogestra/Kicker tram https://www.reynaulds.com/products/Kato-HobbyTrain-Lemke/H14907.aspx and even got a NEM18 DCC decoder for it, with sound. Odd thing is, it would only go forward, and not back (both DC and DCC). I was afraid something is wrong with electric parts or electronics, which would be beyond my skill set, but it looks like the motor is rotating in both directions. Apparently the issue is that the front wheels - which are the only driving wheels - for some reason would not rotate back, even by hand - when connected to the motor gear. They do rotate forward. So when I set it to go backward, the motor works, the cardan rotates, but the motion does not transmit to the gears attached to the wheels. When it goes forward, it works. Something might be mechanically wrong with how it was assembled, perhaps a defective part... any advice would be very much appreciated.

[Kamome]

If the motor turns correctly, then need to work your way towards the wheels. You should be able to eliminate things until you find what the issue is.

 

It sounds as if one of the gears could be binding in one direction. Check for any tight spots, gears jumping out of position or split gears. 

 

If you can take off the bogie and run along a piece of track or along your finger, do the wheels and gears rotate freely when not connected to the rest of the mechanism?

 

If it has a drive-shaft, is it properly connected?

 

Just a case of working through each part from the motor. 

 

These instances are deeply annoying, but are also useful learning exercises when they inevitably occur on other models. 

[Aleks]

Thank you very much! Yes the bogie can be separated easily - it's just hanging by two plastic "ears" somewhat loosely wrapping around two stubs on the body. The issue is that the two tiny wires that bring the current from the front bogie to the motor were soldered to the bogie on the two sides and were fairly tight, and would not let the bogie come off too far away. So the wires got separated today as I was trying to see in between the bogie and the underside of the car. It does look like the bogie has ability to turn in both directions when not connected to the motor mechanism.

 

Looks like I figured it out. The plastic box that holds the front bogie was a little bit open on the back side, i.e. not clicked all the way in. As a result the top of the bogie was a bit off-position, and did not touch properly the gear in the body. So it was catching the rotating motion going forward, but not back, because it was tilted back effectively as a result of the bogie not being fully locked.

 

Now that I have sorted this out, need to try to solder back the two 32-gauge (or so) wires back between the bogie and the body of the car... and ensure the electricity flows  reliably elsewhere as it looks like I may have accidentally loosened some of the other connections.

[cteno4]

Great you figured it out! Do try some practice solders on small like 32g wire before you go at this. It helps to just go do a half dozen practice solders on fine stuff before going at a delicate solder like this.

 

jeff