Reza

Repairing 12v train motor

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Hi guys,
Long time no see! :-)

I have opened a 12v train motor and changed the wheels since the gears were broken. I glued the motor and now, it works perfectly well except that it runs on the opposite direction comparing the other motors. Do you know what is the cause and how I can fix it?
My guess is that the gears or generally speaking, the 12v motors are not necessary compatible with each other, but I may be wrong.

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When you reassembled the motor, is there any chance you put the axles in the opposite way around?  i.e. causing the drive to be reversed?  Not even sure if this is possible, but it would cause this to happen.

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It pays to take a photo before you take mechanisms apart to ensure put back the same or have a very good memory !

Edited by Doug72

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14 hours ago, Doug72 said:

It pays to take a photo before you take mechanisms apart to ensure put back the same or have a very good memory !

I did this recently with the PF train motor. Ironically I took it apart so I COULD reverse the motor. 

PF train motor

One of two things could have happened. Your motor could be flipped front to back. But that would mean some stretched out or misrouted wires inside. Alternatively the gears could be on the wrong side of the pinion gear, meaning they both (orange and white) need to be flipped left to right (both axles). This all presumes you didn't unsolder the motor, in which case you could have reversed the wires. So basically you put something in backwards and your motor is now running...backwards :)

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Although this topic is already 9 months old, it was for me the reason to subscribe to Eurobricks forum. I ran in to the same problem as @Reza. I had 2 defective 12 volt engines, 1 with a worn gear on the wheel shaft and 1 with a crack in the housing. Both were still running but with a lot of noise and very slow. I opened up both engines a couple of months ago to see what was needed to be replaced and I bought two defective engines on a dutch second hand website (marktplaats). Last week I finally started my repair project.

After replacing the defective parts I glued them back together and to my surprise they both run in to the opposite direction of my other engines. Huh... what... I really didn't understand how this was possible.

I did not take any pictures before (or during) disassembly (as suggested above), because to me it seemed pretty straight forward. The wormwheel on the engine shaft and the gears on the wheel shaft can not be assembled in a wrong manner. The metal structures also fit in only one way... So I started my search on internet and run into this topic. I signed up to ask if any progress has been made by the topic starter.

But in the mean time (it takes some time before your account is accepted) I found out what went wrong and I thought it would be nice to share it here. It is possible to take the worm-wheel shaft (with the coil) out of the magnetic housing of the engine. If you put it back in the other way around, the engine runs the other way. I thought I didn't disassemble the engine this much, but probably I did. With the worm-wheel shaft in the other direction the engines now work like new (and in the right direction).

I hope this will be of help to the topic starter or anyone else who faces this problem.

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Posted (edited)
On 3/22/2020 at 10:20 AM, Vanenkelen said:

But in the mean time (it takes some time before your account is accepted) I found out what went wrong and I thought it would be nice to share it here. It is possible to take the worm-wheel shaft (with the coil) out of the magnetic housing of the engine. If you put it back in the other way around, the engine runs the other way. I thought I didn't disassemble the engine this much, but probably I did. With the worm-wheel shaft in the other direction the engines now work like new (and in the right direction).

I bet you did not disassemble the engine this much. After my last post, I discovered there were two types of housing (symmetric to each other). So it is possible that if you put the motor of one type on the housing of the other type, your motor turns on the opposite direction. I have to do more research and experiments on this but will come back to this topic with more details and some photos.

Edited by Reza

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For those of you who have taken the 12v motor apart, how do you open the case? It doesn't seem to have any of the tabs of the 9v motor; do you just have to cut around the entire edge? 

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On 3/28/2020 at 5:45 PM, Commander Wolf said:

For those of you who have taken the 12v motor apart, how do you open the case? It doesn't seem to have any of the tabs of the 9v motor; do you just have to cut around the entire edge? 

Have you checked this?

https://www.eurobricks.com/forum/index.php?/forums/topic/113994-12v-train-motorbb12v-disassembly-and-repair/

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