My son is in senior kindergarten. Wanting to spend time with him, and show him how much fun woodworking could be, I talked to his teacher about a woodworking project we could do with the whole class. I built enough train cars so each child in his class could assemble one, then I visited my son’s school to spend an hour with his class to put everything together. The kids each had one train car to bring home to their parents after we were done.

Talk to the school

When I mentioned this project to my son’s teacher, she was thrilled. We picked a day for me to visit, and I set to work building a set of trains that the kids could assemble. We talked about the different skill levels in the class, as I wanted everyone to have a fun and successful time assembling their train. I decided to make four different cars, each with a slightly different level of difficulty. Once complete, the cars would join together to make a long train.

Design of the kids' train set

The class has a few train cars, as well as a bunch of track sections. I figured if we were going to make trains, they should run on the track they had. I designed the train cars to be on the simpler side, but the sky is the limit.

All the train cars have a flat base, a middle section that gets screwed to the base, four wheels that get screwed to the base, and either one or two screw eyes or hooks that get screwed into the front and/or back of the base. The boxcar and caboose each have an additional roof piece that gets screwed to the top of the middle section.

You could easily leave the smokestack and roof off the engine so the kids could glue them in place, and add a headlight or other details to increase the level of difficulty. There are many details that could have been added to all of these cars to make the assembly more challenging. I avoided using glue in the classroom, as I didn’t think the kids were up for that challenge.

The last detail I made sure of simplifying was to only use #6 screws. I didn’t want to give the kids even more to think about while assembling the trains. I did end up using two types of screws though – 1/2″-long pan head screws to attach the wheels and ¾”-long flat head screws for everything else.

Production line

When setting up all the machining processes for these parts, ensure you’re as accurate as possible. Accuracy on your part makes it easier for kids to be successful assembling the parts.

It’s always important to source your hardware first, but even more so when creating a small production run of pieces. The thought of creating well over 100 tiny wheels didn’t appeal to me at all. I placed an order from Workshop Supply for enough 3/4″-diameter x 3/16″-wide wheels for the project. At 10 cents apiece, they brought a smile to my face when they arrived at my door.

When creating all of these pieces make extra parts. With all the different setups it’s easy to make a mistake.

Start down low

As these train cars are built on top of the bases, so that’s where I started. The width of the base had to be about 1/32″ wider than the inside width of the track. Since the middle section of the track was 3/4″ wide, I made the bases 1/32″ wider than 3/4″. I went with a thickness of 3/8″ and a length of 2-3/4″ for the bases. The only difference was the engine bases had a sloped front, which I cut when I cut the bases to length. The caboose and boxcar roofs were also the same size as the bases, so I cut them now. While I was at it, I ripped enough material for the engine roofs, though I didn’t cut them to final length yet.

Middle sections

I made the middle sections of these cars from spruce, and other than the tanker cars and the front portion of the engine, they were all the same width and thickness. I machined long lengths then cut the parts to length.

The cabooses and engines have 3/8″ holes drilled in them, so that can be done next. Contrasting plugs can now be glued into the engine windows.

The middle sections of the tankers and the front sections of the engines were cut from a 4’ length of 1″-diameter dowel I purchased from the hardware store. To create the flat section on the underside of these parts I just ran the length of dowel through my planer a few times. Be careful not to take too much material off, as the wheels may come into contact with the sides of the dowel.

Countersink and pilot holes

To ensure these parts all come together properly, I countersunk holes in the bases and roofs, and added mating pilot holes in the middle sections.

Start with the countersink holes in the bases and roofs. A pair of countersink holes for #6 x 3/4″ screws are centered on the bases and roofs, and are 5/8″ away from the ends. The holes should be drilled deep enough so the screw heads finish slightly under the wood’s surface. The only roof I didn’t add countersink holes to is the engine roof, as I glued those directly to the engine’s main section. These holes are all drilled on the drill press with a fence and stop to quickly and accurately position all the parts.

Next are all the 3/32″-diameter pilot holes in the middle sections that correspond to the countersink holes in the bases and roofs. Using one of the countersunk bases, align the two parts and use a sharp pencil to poke through the countersink holes and mark where the pilot holes should be drilled. Drill a single pilot hole in the underside of the square engine section, and mark the front and back of this section so you know where to glue the rounded portion of the engine onto it. Don’t worry about the hole in the rounded section of the engine just yet. Be sure to drill pilot holes in the middle sections of the cabooses and boxcars, so their roofs can be attached.

Screw hook and eye pilot holes are next. This is where you have to divide the different bases up, as the engine only gets one pilot hole in its back edge, the cabooses get a hole in the front edge, and the rest get holes on both ends. These holes are centered on the end grain of the part, though be sure to double check the pilot hole size for the screw hooks and eyes you have.

The final set of pilot holes are for the wheels. These holes are centered on the thickness of the bases, and are centred 3/8″ from either end. I drilled all these holes on the drill press, again with a simple fence and a couple stops.

Assemble the engine

End grain joints aren’t overly strong, but they’re good enough for this application. I applied a bit of glue to both the mating end grain faces, rubbed it in, added a bit more glue then brought the parts together and clamped them. Just make sure the flat undersides are even with each other during glue-up.

Now that the engine middle sections are together you can use a screw to fasten an engine base to an engine middle section, mark the location of the pilot hole in the round portion of the engine, and drill that hole. Repeat for all the engine sections.

A 1/4″ hole can now be drilled into the upper edge of the engine for the smokestack, as well as the upper face of the caboose roofs. Cut and glue a length of purchased dowel into these holes. To complete the engines you can glue their roofs in place. A hole also has to be drilled into the top of each tanker middle section to accept the mushroom plugs. Once these holes have been drilled, you can glue in the plugs.

Prepare for the big day

I brought my son into my shop and showed him how all the train cars went together. This gave him some confidence in his skills, and also allowed him to talk to his classmates about how they went together. He felt great about teaching his friends a bit about the trains.

My son’s teacher asked the kids to bring in a #1 Robertson screwdriver, so they could all work on the trains at the same time. About half the students brought a screwdriver in, but sharing screwdrivers worked fine. I first talked about safety, then my son talked a bit about how the parts went together. It was a busy hour, but all the kids had a train car to play with when we were done. Some kids needed no help at all to put their train car together, while others needed help with every step, but I’m pretty sure all the kids had fun doing it.

When we got home I realized I had a few new problems. My son now wanted a lot more of these trains to put together, and my daughter wanted me to come into her class so they could assemble trains. I guess having keen kids is a good problem to have.