Introduction: T Rex Coin Chomper // Dinosaur Piggy Bank
At the end of almost every trip to the store, I end up with a pocket full of change that I save in a jar. It definitely works, but as a maker I think I can do better than an empty Target brand trail mix jar.
I wanted to make a piggy bank that anybody would be proud to display, and have fun using as well. I knew I wanted something in the shape of an animal but I didn't want a standard pig, dog, or cat. I wanted something that would keep my money safe that no one dared to mess with. Anybody can get past a guard dog, but no one messes with a T Rex!
Using few basic tools found in most small garage woodshops, I will show you how to build a T Rex coin chomper of your very own.
If you would like a copy of the template I designed I have a link to it in the video description.
Poplar Board (5.5 inches wide by 3/4 inch thick)
Poplar Board (2 inches wide by 1/4 inch thick)
1/4 inch Dowel
Acrylic Disks x 2
Button Head Hex Screws x 8
Super 77 Spray Adhesive
Double Sided Tape
Black Acrylic Paint
Green Acrylic Paint
Krylon Clear Satin Spray Paint
Coins (To feed your T Rex)
Step 1: Measure and Cut
I started the project off with a poplar board that measured 5 and 1/2 inches wide and 3/4 inches thick. I measured out to 22 and 1/2 inches long and made a mark with a pencil. I extended the mark to the whole width and sides of the board using a square. I then applied painter's tape to the bottom side of the board. This is to help prevent splintering when I cut the board to length on my miter saw. My miter saw isn't big enough to cut the board in one pass so after making the first cut I flipped the board over, lined up the cut with the blade, and made another pass to complete the cut. After cutting the first board I could use it as a template to mark where I needed to cut the next board.
I measured out and cut enough wood to make two complete coin chompers. If you only want to make one, measure out to 11 and 1/4 inches instead of 22 and 1/2 inches
Step 2: Glue Up Boards and Attach Template
With the boards cut to length I glued them together using Titebond Original Wood Glue. This gives me a panel wide enough for the template I created. It's important to use enough pressure when clamping that you close any seams in the boards but not so much that you start to bow them. I also made sure to clean up any glue squeeze out before it dried. After letting the panel sit overnight to allow the glue to dry I took the panel out of the clamps. I then attached the template I created using Super 77 Spray adhesive.
Step 3: Cut Out Both Halves
The panel was wider than I needed so I trimmed off the excess wood using my bandsaw and saved the piece to use in a future project. As mentioned before I glued up a panel big enough for two T Rex coin chompers. I'm only building one so I cut off the other side with a template on it and saved it to build another T Rex coin chomper in the future.
Using my jigsaw I cut out each half of the T Rex. I then removed the template from one of the halves.
Step 4: Attach Halves Together
Using a few strips of double sided tape I temporarily attached both halves together.
Step 5: Cut Out Shape
I originally wanted to cut the pieces out using my jigsaw but I didn't have a blade long enough to cut through both pieces cleanly and I was getting an lot of blade deflection causing it to wander and leaving me with an out of square/diagonal cut. Using my bandsaw I was able to cut the pieces out however the blade I had on hand was too wide and in fact really dull and it seemed to do more burning than it did cutting. I had the most trouble when cutting out the teeth as the blade was too wide to navigate in that tiny area. I was able to nibble away the material however this means more work filing later on.
Step 6: Refining the Shape With Sanding and Filing
Using a combination of my belt and spindle sander I was able to sand the cut smooth and down to the line. The sanders were great for most areas however there's some spot where they just couldn't reach. To get in those areas I used a couple of files.
Step 7: Adding Alignment Pins and Routing Coin Slot
With a 1/4 inch bit in my drill press I drilled two holes for dowels that will be used for alignment later on. With the holes drilled I could separate the two halves and remove the double stick tape. I mounted the templates that will be used to route the coin slot using Super 77 spray adhesive. I originally planned on using my Dremel to route out the coin slot, but when setting the cut depth on a piece of scrap wood it kept shutting off during the cut so I switched over to a trim router. The trim router is a lot bigger than a Dremel and harder to handle so the cut isn't as clean as I would have liked however this will be on the inside of the coin chomper and will never be seen. I routed to a depth of 1/16th of an inch on both halves.
Step 8: Drilling the Coin Holder Holes
In order to drill the hole in the same spot on both pieces I realigned them using two 1/4 inch thick dowels inserted into the alignment holes drilled in the previous step. Using a 3 and 5/64th inch hole saw in my drill press I drilled out the center hole from both of the pieces.
The hole saw is not deep enough to drill a hole in both pieces in one shot. It does however have a long center bit that keeps it drilling straight down and prevents it from wandering. As soon as the center bit made a mark through to the half on the bottom I separated the halves of the T Rex. This pilot hole allowed me to drill the hole in each half in the exact same position. This ensured that the hole would line up when I attached the halves back together. I then drilled each half separately. Doing this allowed me to make a deeper hole than my hole saw is capable of.
In order to reduce tear out and get the cleanest hole possible I would drill about half way through, flip the piece over and finish the hole on the other side.
Step 9: Paint Coin Slot and Glue Together
With the pieces still separated I took this opportunity to paint the inside of the coin slot black as It would be impossible to do once they were glued together. After letting the paint dry I reinserted the dowels and applied Titebond Original Wood Glue glue to both halves of the T Rex and glued them together permanently. I applied clamps and let the glue dry overnight.
Step 10: Cut Alignment Pins and Final Sanding
After removing the clamps I cut the dowels flush with the surface using my flush cut saw. After removing the template I used a combination of my random orbit sander and hand sanding to sand the entire body of the t rex smooth. I used strips of sandpaper glued to Popsicle sticks to sand the tough to reach areas of the teeth. I also rounded over all of the edges with sand paper to give the piece a smoother more premium feel
Step 11: Drill Acrylic
I found these 3.54 inch wide acrylic disks at my local craft store that I will be using as windows to see the contents of the coin chomper. I temporarily attached the drilling template I made with Super 77 spray adhesive to the disks. With a 1/8th inch drill bit I drilled 4 holes in each of the acrylic disks. Using the pieces of acrylic as a template I attached them to the body with painter's tape and drilled out 7/64th inch holes where the screws will mount into.
Step 12: Sanding and Attaching Arms
Off camera I cut the arms of the T Rex out of a 1/4 inch thick poplar board using my bandsaw. Using 220 grit sandpaper I smoothed out the cut and rounded over the edges. I attached the arms to the rest of the body using wood glue. I also used a dab of hot glue to hold the pieces in place and keep them from shifting until I could add a clamp to the arms. After letting the glue dry for about an hour I removed the clamp.
Step 13: Painting Color and Clear Coat
With the arms attached, the holes drilled, and the piece sanded smooth I could start painting. The paint I am using is just regular run of the mill acrylic craft paint. I painted the sides first and then moved onto the flat faces of the T Rex. The paint goes on thin, but after about three coats I had a nice opaque color. To speed up the drying process of the acrylic paint I used a hair dryer in between each coat. After all of the acrylic paint was dry I added 4 coats of Krylon clear satin spray paint for durability. Using a 1/4 inch dowel dipped in black acrylic paint I stamped out an outline of an eye for the t rex and filled it in with a paint brush. I also added some nostrils so he can breath.
Step 14: Attaching the Acrylic Windows
I used 4 button head hex screws on each side to attach the acrylic windows to the T Rex. This holds the windows firmly in place and provides easy access to the coins when they are ready to be used.
Step 15: Start Collecting Coins!
The only thing left to do now is to fed your T Rex lots of yummy coins!
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