The Deadliest Catch Award

The Deadliest Catch was a fundraising event held by Ann Arbor Hands-On Museum few years ago. Contestants created various humorous trophy awards to give away. One contestant made a trophy using an Iguana Head mounted on a pole with a mouth to be driven by a small toy motor. The motor wasn’t hooked up to a battery and it was a still-life trophy. The judges awarded the trophy back to the original contestant as the Deadliest Catch winner.

When I first saw it, I wanted to see the mouth to move. So, I went to make one for myself.

The original Iguana Head was a Wild Republic Iguana Pincher toy bought at Wal-Mart. I was lucky to find one available online thru Amazon.

One of the first things I noticed was the small original gears. The contestant used a Laser machine to cut gears out of a plastic sheet. I was thinking that making small gears requires lots of engineering work. That means lots of precision calculations which are time-consuming tasks. There was no point of making it expensive because I wanted to have fun making a simple moving toy.

The gears in the original trophy had anywhere from 24 teeth to 48 teeth. That number of teeth can be found in small precision plastic gears. I found that I don’t need precision gears to make a toy. I went to make new small gears.

So, I made the gear teeth larger to allow more play when the gears meshed together.  I cut down the number of gear teeth to keep the diameter of the gear small. I did this by using gear tool software from Inkscape software to make three different gear sizes. I selected a circular pitch of 0.2 inch to make the pinion gear of 10 teeth, a second compound gear of 18 and 10 teeth, and the driven gear of 24 teeth. Circular pitch is circular distance of the center of one tooth to the center of the next tooth. Inkscape only works with circular pitch.

From there, I used Inkscape to transfer the data to be read by Epilog 50W laser machines at Maker Works of Ann Arbor, Michigan. 

I used 1/8 thick plywood from my scrap box to construct a gearbox. I made the size of the box just big enough to put all the gears together.  I used 3 layers of plywood to make thicker gears.   I drilled a hole near the axle to have crank pin installed.

The original Toy Grabber Iguana Head had a trigger attached to a string. There was a torsion spring inside the head. So, when the trigger is pulled, the head goes down. When it is released, the spring pushes the head back up.

Sorry, no picture is available to show the spring in the original toy. I torn it apart before I start taking pictures.

When I replaced the trigger with gears, my initial design idea didn’t work. I went through several designs to find the current design that worked consistently. The vertical pole with a slot slider pushes the head up when the crank pin goes up. When the crank pin pushes the pole down, it allows the weight of the head to come down.

When I first used one 1.5 volt battery to power the toy motor, the motor didn’t have enough torque to push the head up. Then when I added another volt 1.5 volt battery connected in series, the motor speed was too fast, which made the head bobble too fast.  I re-arranged the wiring to be in parallel, giving more current and torque to the motor while keeping the same motor speed. Bingo, I was satisfied.

I added a spring return push down On/Off button to add a playful action for friends to play with. Finally, I used the laser machine to make the Deadliest Catch sign.

Now, I’m happy. All I have to do is to push down the button to watch the mouth move up and down.