2026-10-13 - Repairing a Toy Train
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As a break from my usual repairs, I was tasked with repairing a
small toy train some time ago[0]. This train has a small motor inside
so it can move on its own. I didn't actually get a complete train,
just a bag full of parts from two trains, so I had to try to build
something working out of those parts. When the train is assembled,
there is a battery compartment for a AAA battery on top[1]. The
mechanism inside can be accessed by unscrewing four screws on the
bottom[2-3]. Unfortunately, I only managed to build one functioning
train because the remaining parts didn't contain all the necessary
gears for another one[4].

The first thing I did was to clean and grease the motor a bit[5-9]. In
particular, the brushes were covered in old grease that I cleaned
off using isopropyl alcohol[6]. I also cleaned and greased the gears
and axles. Note that the front wheels actually turn independently of
the axle, so the front axle doesn't need to move at all. Originally,
the motor was only pressed against some contacts, so the connection
wasn't very good[10]. This is probably why the train was defective
(and thus taken apart) in the first place. I ended up simply soldering
some short wires to connect the motor properly[11-12]. The contacts
on the top part with the battery compartment still are just pressed
against the contacts on the bottom part[13], but at least they are a
bit springy, so they don't lose contact as easily. If that connection
ever becomes a problem, I can still solder some wires there as well.

Well, that concludes another short repair. Camcorders and VCRs are a
lot more complex and interesting, but repairing small contact issues
like in this toy train can go a long way when trying to avoid throwing
devices away.

[0] gopher://lumidify.org/I/phlog/2026-10-13-toy-train/train.jpg
[1] gopher://lumidify.org/I/phlog/2026-10-13-toy-train/battery_compartment.jpg
[2] gopher://lumidify.org/I/phlog/2026-10-13-toy-train/bottom_screws.jpg
[3] gopher://lumidify.org/I/phlog/2026-10-13-toy-train/gears_assembled.jpg
[4] gopher://lumidify.org/I/phlog/2026-10-13-toy-train/remaining_pieces.jpg
[5] gopher://lumidify.org/I/phlog/2026-10-13-toy-train/motor1.jpg
[6] gopher://lumidify.org/I/phlog/2026-10-13-toy-train/motor2.jpg
[7] gopher://lumidify.org/I/phlog/2026-10-13-toy-train/motor3.jpg
[8] gopher://lumidify.org/I/phlog/2026-10-13-toy-train/motor4.jpg
[9] gopher://lumidify.org/I/phlog/2026-10-13-toy-train/motor5.jpg
[10] gopher://lumidify.org/I/phlog/2026-10-13-toy-train/motor_contacts.jpg
[11] gopher://lumidify.org/I/phlog/2026-10-13-toy-train/motor_contacts_fixed1.jpg
[12] gopher://lumidify.org/I/phlog/2026-10-13-toy-train/motor_contacts_fixed2.jpg
[13] gopher://lumidify.org/I/phlog/2026-10-13-toy-train/top_contacts.jpg