(Toy) train wreck

Year or two ago we got our kid a Brio toy train set with some length of track and remotely controllable train. Back then it wasn't very interesting (to him) so that got buried for a while, but recently he got interested again, especially after we got him some more track (total length now being around 4 metres or so - fortunately we had one spare room to lay it out).

It was expected that the train would not last long as he likes to stop it by holding it when it's run on motor and pushing it forcefully, straining the gears and the motor. So it was not very surprising that it started to fail relatively quickly, eventually not moving anymore at all (but it still makes usual sounds and so on it electrics wasn't dead).

New ones are a bit expensive so I decided to see what could be done. Some one night the train mysteriously vanished from home (event that didn't go unnoticed by the small one) and was taken apart the next day.

The text on train says Brio RC-101, I tried to look it up but couldn't find it anymore so it might be no longer available (or maybe it's just sold as a set I couldn't find on quick search). I'd expect that newer models are similar in construction, prices for those (just train, no remote) were around 20-30 euros.

First problem was that it was closed with those damn triangle-shaped screws, four of them total. 2mm flat screwdriver can be used to open them, but you need to be very very careful - if the blade slips you will very likely damage the screw head and make rest of the process more difficult, if not impossible (note also that there apparently are several triangle sizes, others may need larger blade).

Inside was motor mechanism - nothing too fancy. I didn't bother to open it further to see the electronics (IR receptor as train is remote controllable, speakers and such) so no pictures of that, sorry. I don't expect them to be too interesting anyway, main chip most likely a COB with glob on top, a few passives, transistors and others and nothing more.

Gearbox comes out easily enough, aside the cover it isn't held in place at all. Fortunately no more fancy screws, gearbox was closed with two phillips-type screws. After popping it open the motor comes out easily enough. And yes, it was the motor that was broken, not the plastic wheels. Those would've been impossible to repair.

Here I have replaced the motor already, original motor is the one that not connected. It was annoyingly small - 8x10x15mm, excluding the shaft, so finding replacement was a bit difficult. I ended up ordering one from dx.com, sku 275090. It isn't exact replacement and most likely runs slower than original but no matter, important thing is that it runs. You can also see that new one is a bit shorter so I had to put in a bit glue to hold it in place. 

And of course despite trying to decipher markings on the motors the first time leads were the wrong and train reversed when it should be driving forward. Not difficult to fix but annoying.

One more picture of motor/gearbox mechanism while open. Note few small metal plates in compartment where the gearbox should be - four of them are used as spacers, placed between the train frame and gearbox. No idea why - maybe they have several gearbox designs, some of which are slightly larger.

Putting it all together was simple enough, and it's alive!

On how long it will last this time, well, your guess is as good as mine...


And somehow I predict that I have train track building duty this evening.

Later addition: After some observation train clearly (to me) is slower and weaker than before, but no matter. It would need 3v motor (train uses 2 AA batteries - replacement motor was 4,5v), but those seem to be even harder to find. Kid doesn't care so no matter, it's fine (and taking abuse just like before, maybe I should start looking for better replacement motor immediately...)


Post mortem seven months later: This train does not a good submarine make. In fact I just found out that water pretty much kills it permanently (not very surprising, really, but apparently this is a very difficult concept for small kids to grasp). All's not lost though, take one plastic gear off from the drive mechanism and you have pushable train instead.
I don't really feel like taking it apart to examine electronics there, since I pretty much expect to find just a small, cheap PCB with single (glob-covered) chip on it with maybe some passives and a speaker. Not very exciting.