I'm sure we've all seen those small wooden 3D dinosaur models. I had a few that I loved as a kid, but they all shared a common flaw. They were much too small!! As a father I set about to rectify that problem for my son. In the following steps I'll provide all the information you'll need to make your very own 6 foot tall T-Rex model!
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Step 1: Tools & Materials
2) 4'x8' sheets of Oak Plywood (*see notes below)
Templates printed on 24"x36" sheets (from attached PDF on Step 2)
Wood Stain & Finish (optional but recommended)
Felt with adhesive backing
Jigsaw blades - 12tpi (teeth per inch) skinny blades
Drill with 1/4" bit
Sander w/ various grits
Router w/ 1/4" roundover bit
*NOTE: My T-Rex was sized and built using 1/2" thick plywood. Upon completion I realized that the legs, tail, and spine are a bit too flimsy. I'm going to recut just these pieces using 3/4" plywood. I would recommend using 3/4" thick for this project if you only want to buy two sheets of plywood, but keep in mind there is a weight advantage by using 1/2" for all the other pieces. I went with oak because it has a nicer grain and accepts stain better than pine. If you choose to go with pine, you'll need to use wood conditioner before applying any stain.
Step 2: Templates
Take the attached PDF and print the template sheets on 24"x36" paper You'll need to splice a few of the pieces together as they are too large to fit on a single sheet.
Plywood has a good face and a bad face. Lay your sheets good face down and arrange the templates as shown on the attached Guide PDF. Visualize where your T-Rex will be and from which angle it will be most visible. Some of your pieces may have to be flipped so that the "bad side" is not visible on the final model. Trace all of the piece onto the plywood. Pieces marked as "R/L" will need both a right and left piece traced. Be sure to include the "cloud" around 3 of the notches on piece 8.
Step 3: Cut Pieces
Begin cutting out all of the pieces using the jig saw. DO NOT cut out the notches at this time! There's a lot of linear feet to cut, so this step will take some time.
A few Tips:
I found that if I drilled a 1/4" hole at the base of a notch, it was a lot easier to cut the piece out starting at the hole, than if I had to cut towards it from the edge of the plywood.
On the skull pieces, start by cutting out the mouth, across the top of the teeth. Then go back in and cut out each individual tooth. Next, drill a hole in each of the cranial sockets, and cut these out as well. Finally cut the head from the plywood.
Also, it's better to frequently switch to a fresh blade, than to tear up your plywood with a dull one.
Step 4: Router & Notch
If you have any small mistakes or rough cuts, use the sander at this point to smooth them out.
Take a scrap piece of wood and run the router along both sides. Adjust the depth of the round to your liking. For my 1/2" thick plywood I went with approximately 3/16" radius round. Run the router over all the edges of your pieces, with the exception of the teeth. These look much better if left sharp. On some of the smaller pieces I turned the router upside down and ran the piece over the top of it. This worked well, but is quite dangerous so be -very- careful if you try this technique.
Take another piece of scrap wood and using it as a guide re-mark the notches on each piece. These plans were originally sized for 1/2" plywood, so if you are using 3/4" or a combination of both, adjustments will need to be made. Do not re-mark the clouded notches on piece 8 until the notches have been cut out of piece 9. The notches in 8 must line up with the three notches in piece 9.
Cut all of the notches out using the jigsaw, test fitting with scrap wood as you proceed. Be sure to test fit ALL notches prior to moving on.
Remember, do not round off any of the notches with the router.
Step 5: Assembly
Cut some strips of adhesive felt that match your plywood thickness. These will be used in some of the notches to ensure a tight fit. I only used felt at the head, and hips. All other pieces were left as they were. Assemble the T-Rex per the attached diagram (also part of the Guide PDF in step 2) Start at the hips, legs, tail and then upper body.
Step 6: Final Suggestions
At this point, if you like the natural look, your T-Rex is complete! Personally, I plan to take my time staining and finishing each piece to match my bookshelf. (a nice dark red color) In addition I will be upgrading the legs, tail, and spine to 3/4" ply to provide greater stability. Once this is complete I will post final photos.
Alternate Idea for the Adventurous:
Try making this using pink solid core foam insulation instead of plywood. Cover the skeleton with chicken wire and then coat with stucco for an awesome backyard statue!
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Step 7: BONUS!
As a "thank you" for all those who voted for this instructable I decided to add a Bonus Page!
Below you will find the CAD file for the Trex model pieces.
I've also attached everything you need to make a Pteradon!! This project has been sized to fit a single 24x48 sheet of 5.2mm ply. You can buy this for under $8 at Home Depot.
The Pteradon will have a 4'-4" wingspan, and the body is around 2' long when complete. I've included CAD and PDF files for this project. As before, print the template sheets on 24"x36" sheets.
Enjoy, and please post pics if you build it!! Thanks!
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