Train Tutorial 4

Making a Train...Start to Finish

Part 1 - Building Articulated Trucks

Part 2 - Building the Locomotive

Part 3 - Painting

Part 4 - Attaching Axles, Wheels, and Connectors

Part 4 - Attaching Axles, Wheels, and Connectors

I'm going to start this section by talking about magnetic connectors. The magnet is pretty simple. It's a 1/2" diameter ceramic magnet with a small hole in the middle. These can be purchased from a number of different places. I've usually purchased mine from Cherry Tree Toys (here's a link). I use furniture nails to hold the magnet in place. There are different types of nails that can produce acceptable results. The middle nail pictured above is what I used to be able to obtain from Cherry Tree. But, sadly, they no longer sell them. In fact, I can't find the middle nail anywhere on the internet these days (early 2013). I've searched high and low. This is unfortunate because I really like the middle nail. I like the way it looks and I like the ridges on the shaft. The ridges give me confidence that it will never come loose. Since this is a child's toy I'm worried about the possibility of a nail coming out. I've never actually had a connector nail come loose from my trains--so maybe I'm being overly cautious. Anyway, the nail on the left is the nail Cherry Tree sells today (even though the picture on their website still shows the middle nail). It's dome is higher, which is ok. But what I don't like is that the diameter of the head is slightly less than 1/2" so it doesn't match the magnet very well. The nail on the right is the best I can find right now. The dome is just slightly larger than 1/2" and the edges are less rounded than the ideal nail. But it's the best I can find right now.

Because my nail (the one on the right in the previous step's photo) doesn't have shaft ridges, I worry about it coming loose. In order to ease my concerns I quickly cut my own notches in the shaft. My theory is that a shaft with notches will have better holding power when glued in place than a smooth-shafted nail. Then I glue the nail and magnet in place with Gorilla Glue (or a comparable glue). I use Gorilla Glue for this and all other applications that involve metal surfaces. Gorilla Glue is a polyurethane glue that can bond to many different types of surfaces.

IMPORTANT: Be sure you test the polarity of your magnets before attaching them to ensure they match other trains. Not arranging the polarity correctly may render a car useless (or at least not compatible with other cars). I have an old, beat up truck that I leave kicking around my workshop to make sure I always get the polarity right.

During painting and lacquering, the axle holes on the truck and wheels become clogged. Now is a good time to quickly re-drill the holes by hand.

It's time to make axles. As mentioned previously, 3/32" brass tubing makes a nice axle. The stuff I buy is made by K&S Engineering. The tubing is sold in various lengths and has a hole diameter of .066". One online retailer I've purchased this from is HobbyPeople.net who sells brass tubing for less than a dollar a foot.

The tricky thing is cutting the brass tubing to a consistent length. I used to cut the tubing with a hack saw (by hand). It was a pain, and every axle turned out a different length. I've made a rudimentary jig out of scrap wood to help me cut axles quickly and consistently using my handy Dremel rotary tool. The jig consists of a length of 2x4 with a block mounted to one end. Two thin, parallel pieces of wood are glued to the 2x4 to hold the brass tube in place during cutting. A third piece of wood dictates the length of the tube segments.

I hope these pictures are worth a 1,000 words each because I don't think my explanation is very helpful here. Basically, I set the rotary tool in the jig with the end up against the wood block and put the brass tube in place. I turn on the tool and basically tip it downward to cut the tube. I'm sure there are many other ways to accomplish this task. This is just what I've come up with and it works fine. The correct length of the axle will depend on the width of the truck, the thickness of the wheel, and the type of furniture nail cap used. It's best to err on the side of the axle being too long since an axle that is too short is useless but an axle that is too long can still be used or be cut down further. Typically my axles are 1 3/16" long.

After having cut my axles to length, I glue a small furniture nail into one end. These are smaller than the nails used for the magnet connectors. The heads are about 11/32" wide. I buy these at Lowe's. After putting a bit of Gorilla Glue on the nail, I insert it into the end of an axle and twist it around a bit to make sure the glue has nice coverage. The nail fits snugly into the tube. The key to success of this system, I believe, is that the glue expands as it cures. Because there's already little room to spare, the expanding glue holds the nail very tightly in place. In fact, after the glue is fully cured (after a couple days) you'll find that it is difficult or impossible to remove the nail even if you try. That's not to say the bond can't fail. I have seen one nail come loose in train after 7 years of use by my children. That's a pretty good track record but it's not perfect. So be warned. This is still a safety concern. If you choose to use sharp nails in a children's toy then you're accepting the inherent risks that go along with it. One thing you might consider is trimming off the sharp point of the nail. That way if it does come loose it's not as dangerous to a child as it might otherwise be.

Let the glue dry over night. Handling your work before the glue cures may result in weaker bonds. You might be tempted to use lots of glue; thinking it will ensure the nail never comes loose. But since the glue expands as it dries, you will find excess glue comes bubbling out and can form a big blob which will interfere with the wheel as seen in the picture on the right. This is just a small amount of excess. It can get much worse if you use too much glue. I use pliers to pull off excess glue. Sometimes a rotary tool can be helpful to cut or saw off particularly large blobs.

Depending on the length of your axles and nails, you may find that the nails run into each other inside the axle tube and prevent them from being fully inserted unless you shorten one of the nails with wire cutters or pliers.

Next, I assemble the truck and wheels with the axles that already have nails glued into one end. Then I glue the final nails in place. I actually find this step challenging. I want to use as much glue as possible to reduce the likelihood of a nail coming out. However, if I use too much glue it's going to come bubbling out and stick to the wheels. Plus there's often small amounts of excess glue that comes oozing out as the nail gets inserted and if you're not very careful you'll end up with glue on on your wheel.

This is it! The last step! I use a single #5 wood screws to attach the truck to the body of the locomotive. First I screw it on tight then dial it back just enough to achieve full range of motion.

Here are some additional pictures of the finished product. I hope you found this tutorial useful. Let me know if you have questions or need clarification about anything. Also, I'd love to hear your ideas. Email me at woodtrains@gmail.com.

Part 1 - Building Articulated Trucks

Part 2 - Building the Locomotive

Part 3 - Painting

Part 4 - Attaching Axles, Wheels, and Connectors