Make a Train Coin Bank
This train shaped bank makes a great gift for a young one or a train enthusiast. It is made from ash and walnut and will highlight your turning skills.
The train body finishes at 3-3/4″ diameter, and is turned from a block of ash approximately 4″ square by 10″ long. I used 16/4 stock, but you can glue up 8/4 stock to get the required thickness. In this case, be aware of the pattern of the grain to try and hide the glue line.
Mount the blank between centres on your lathe and turn it round and smooth. Alignment of the cab and wheels will be easier if the diameter of the body is consistent over its length so use a caliper and refine the shape as needed.
The inside of the train body needs to be hollowed to hold the coins. The walls will finish at 3/8″ thick. After mounting the blank in a chuck, I drilled out most of the waste with a 3″ Forstner bit, but any hollowing approach will work. Start by truing the end of the body with a skew and then reduce the lathe speed for drilling. Retract the Forstner bit every inch or so to clear the chips until you get to a depth of about 6″; this will leave about 3″ of mass at the front of the train. Depending on the size of your Forstner bit, you may need to use a scraper to thin the walls until they are about 3/8″ thick. Use a drum sander or a slotted dowel with sandpaper to smooth the inside.
With the inside complete, reverse the blank so the chuck jaws are tightened against the inside of the body. Support the other end of the blank using your tailstock and shape the front end. Slow the lathe speed and sand the entire body, then stop the lathe and do your final sanding along the length of the body.
Turn a Cylinder
Turn a consistent diameter cylinder using a roughing gouge followed by a skew or scraper. Add a tenon on one end to fit your chuck.
Hollow the Body
Bedrosian uses a home-built steady rest to stabilize the blank as it is hollowed with a Forstner bit. Thin the walls to about 3/8” using a scraper.
Sand the Inside
Attach a steel rod to a 2” drum sander to smooth the inside of the train body.
Add the Nose
Shape the front of the train body using a skew or spindle gouge. Use the tail rest until only a small nib is remaining.
Create a Carriage
Hot-melt glue two plywood sides to the cylinder to act as a carriage while cutting the joinery. Use your jointer fence and a square to keep both sides at 90 degrees to the table.
Slot the Cab Opening
Fasten a stop block to the rip fence and make two cuts in the body to create a 3/4” wide opening for the cab.
Rout for the Axles
Use a core box bit the same size as the axle dowels to rout three coves across the bottom of the train body.
Rabbet for a Tight Fit
Scribe a line and then use a shoulder plane to form a shallow rabbet so the train cab fits snuggly into the body.
Hollow Chisel the Cab
Use a hollow chisel mortiser or a drill press to open a slot for the coins and to add windows to the cab. It doesn't have to be pretty, as the opening will eventually get covered.
Turn the Smoke Stack
Bedrosian uses a ½” open ended wrench to size the tenon on the bottom of the smoke stack.
Turn the wheels
Use a wooden faceplate with a short centering dowel to align each wheel as it is turned. Small squares of double-sided tape hold the wheel in place on the faceplate.
Glue the axles to the body
Use 5-minute epoxy to glue each axle to the coves in the train body. Elastic bands hold the axle while the epoxy dries.
Cut joinery for the wheels, cab and smoke stack
To assist with cutting the joinery in the train body, I secured it to a simple plywood carriage. Measure the outside diameter of the body and cut the plywood to this width (approximately 3-3/4″); cut the length to about 9″. Hold both boards parallel and tack them to the top and bottom of the train body. You can now safely reference all cuts off the parallel sides of the carriage.
The train cab fits in a 3/4″ wide by 4″ long slot that is milled in the centre of the train body. Mark a centre line along the length of the train body and then mark 3/8″ on either side. With a rip blade in your table saw, run the sled along the fence to make the two outside cuts for the slot. Be sure to fasten a stop block to the fence to limit the length of the cut to 4″. Square up the end of the slot with a chisel. Referencing off the same centre line, measure 1-3/8″ back from the front of the train body and drill a 1/2″ diameter hole for the smoke stack.
Complete the train body by routing three coves across the bottom for the axles. Use a right-angle sled to push the carriage and the body across a 1/2″ diameter core-box bit which matches the 1/2″ diameter of the axles. The depth of the cut is not critical as long as you don’t cut through the 3/8″ thick wall of the train body. I positioned the center of the rear axle 1″ from the rear (open) end of the train body. The center of the middle and front axles were positioned 3″ and 7″, respectively, from the rear of the body. Use a knife to remove the plywood carriage from the body.
Start with a piece of 4/4 walnut at least 4″ wide and 5″ long for the cab and mill it to about 1/32″ thicker than the width of the slot in the train body. I cut a shallow rabbet on both faces of the cab to assist with gluing it into the train body. Use a marking gauge to scribe a line 3/8″ from the end on the wide faces of the cab; this should match the wall thickness of the train body. Cut a shallow rabbet up to the scribe line using a shoulder plane. Check the fit often until the rabbeted portion fits snuggly in the slot and the shoulders are tight to the train body. Mark the finished width of the cab from the back end of the train body and rip it so it is flush and then crosscut it to finished length.
Decorate the cab with four windows and then cut the coin slot. I used my hollow chisel mortiser with a 5/16″ chisel for the windows, but round holes will also work. I switched to a 1/4″ chisel for the coin slot and cut in from both ends of the cab to create a slot about 1-3/4″ wide. Alternatively, you could drill overlapping holes and chisel out the waste. As long as a toonie fits through the opening, it can be a little rough since it will be hidden by the top cap.
The cab is finished with an over-sized 5/16″ thick top cap. Rout a 1-1/2″ long coin slot along the middle of the top cap with a 3/16″ bit while the piece is still long, then cut it to length. Drill holes for the pegs on both ends of the slot and transfer these locations to the top of the cab. Limit the drilling depth into the cab to avoid interfering with the windows. Glue the top cap and the pegs to the cab and then use epoxy to glue the cab into the slot in the train body. The epoxy is flexible enough for this cross-grain joint to allow for the small seasonal change in the width of the cab.
Turn the smoke stack from a 1-1/4″ square piece of walnut mounted in a chuck. The only critical dimension is the tenon which needs to fit in the 1/2″ hole in the train body. Shape the rest of the smoke stack so it flares near the top and is approximately 2-1/4″ long. Cut the tenon so it is slightly shorter than the hole in the train body and glue it in place. Apply your favourite finish to the entire train bank, staying clear of the three cove cuts in the bottom.
Wheels and axles
Turn the six wheels from a walnut board that is just over 1/2″ thick. Cut the stock into 2″ squares and drill a 1/2″ diameter hole by 1/4″ deep in the centre of each square. Drill the same size hole into a small wooden faceplate and glue in a short piece of wooden dowel to align the wheel on the lathe. Use double-sided tape to hold each wheel in place as you shape the front and turn it round. Use a caliper to be sure each wheel has the same diameter of about 1-3/4″; this will prevent the train from rocking when it is completed. It’s possible to purchase wheels, and some other project parts, from suppliers like Workshop Supply and Lee Valley. Epoxy the wheels to the ends of the axles.
Apply a finish
Apply finish to the project, leaving a bare spot on the axles and in the coves which are cut into the underside of the train body. This is so you can epoxy the axles to the train body. Be sure each axle is centered on the train body before allowing the epoxy to dry, so the wheels are aligned and project the same distance from both sides.
Close in the back of the train body with a piece of 1/8″ thick clear acrylic held in place with four small screws. I typically use #0 Robertson screws (which uses the yellow handled driver) to make it less convenient to rob the bank.
If the bank is a gift for a young one, you may want to start their savings with a loonie or toonie minted in the same year they were born.