One of the most popular evergreen toys is also one of the simplest, wooden track with push-along trains. We all know the brand name, and savvy parents know to pick up the much cheaper knock-off because the kid won’t know the difference. But a really cool kid shouldn’t have to push their train around by hand, and thus [Lauri] has given the wooden track a real, powered, locomotive.
In the 3D printed chassis goes a small geared motor driving one axle, with an ESP32 and a motor driver taking care of the smarts. Power comes from an 18650 cell, which almost looks like the right scale for a fake steam boiler. The surprise with this train comes in the front axle, this machine has steering. We’re curious, because isn’t the whole point of a train that the track directs it where it needs to go? Or perhaps a little help is required in the absence of a child’s guidance when it comes to points. Either way, with remote control we guess there would be few kids who wouldn’t want one. We certainly do.
As a parent, I discovered that TOMY-brand battery powered Thomas the Tank Engine engines run just fine on these wooden tracks.
The real hack for my family was granddad building a jig that allowed him to cut out tracks out of scrap wood,
That is the most valuable part to learn about railways: everyone cares for locomotives, but you rise and fall with the existence of lots of tracks (to reach your customer) and cheap cars, so it doesn’t hurt to leave them a week or two at your customer for loading. And keep in mind: the cheapest siding is not a digitalized one, but one with only a lever and a key, and the cheapest car has no electricity on board.
It is very clear in the description, te steering is for the track changes, so I guess this is a nice option.
With the ESP inside, looks like a nice project to add scratch programming, so the kids can programm the train movements…
For the tracks: https://www.amazon.com/MLCS-Train-Track-Bit-piece/dp/B000GG09R2
“Power comes from an 18650 cell”
As a potential ‘child toy’, extreme care should be taken to construct a safe device by ensuring that the battery can never be accidentally shorted (more substantial than the black vinyl tape.) An added fuse/breaker perhaps could be added.
Best if the pictured prototyped was fully adult supervised during play; even older kids will consider pushing the rolling loco by hand.
A good reminder to use so-called “protected” cells for applications like this — ones with overcurrent protection built-in.
If it’s a tabbed one (like the one apparently used in this project), it’s generally intended to be built (welded) into packs or devices with their own battery management system, and the cell itself (usually) doesn’t have protection built in.
If it’s a button-top type cell, it’s intended to be replaceable by the end user, so (usually) has a protection circuit built in.
Short(har) of testing it, the actual manufacturer’s datasheet would say whether it does or not.
Given the warning printed on this cell, I’d be wary about using it for this application.
This is a good areminder. The battery will be replaced with protected cell in correct size. As I am not sure if I could fit full size 18650 there I have not invested in better battery yet.
I’ve been working on a motorized wooden train track engine for a few years now, and it’s surprisingly difficult. The balance between enough traction to climb bridges but not enough to climb out of the track is a subtle problem. I’ve found that the durometer of the rubber has an impact, as well as the shape of the wheels on either side of the rubber, and lots of weight in the engine helps a lot. I would like to add a de-coupler, but so far I don’t have any great solutions. It’s also important to make sure that if the kid pushes the train by hand it doesn’t destroy the geartrain. I want to incorporate a speed controller into an adjacent car that senses its speed and (wirelessly?) controls the speed of the engine. I would make it wired, but a cheap, robust, unshortable, articulated magnetic electrical connector has not made itself apparent to me yet. https://youtu.be/G8-loH4rqWY?si=ynOJKyMhkUgTDLAH