Introduction: Recycled Fun Cardboard Cad-A-Pult

The task was to create a something with a green twist. Okay, I'm good with that. A chance to win a Zing Laser cutter for my class is an added bonus. Now if I could add some fun and learning into the mix, it would make it even better.

So what to do? Hmmmm?

My students love to build things and throw stuff so let's put both together! Now, for the green part. Let's see if we can make something that is recyclable and fun! Looking around the classroom, I see lots of cardboard (used shipping boxes) and a good supply of Elmer's glue. So, with a little help from Autodesk's CAD program Inventor, I whipped up a nice little Catapult (Hence "CAD-A-Pult").

Next, to obtain more cardboard, I put out an email to other teachers in my school for boxes. Boy, did the boxes pour in!

If you would like a copy of the plans, information on how to obtain them free of charge is listed after the assembly instructions.


Step 1: An Idea Is Recycled

A quick jump into Autodesk's CAD program Inventor and the CAD-A-Pult is born. The basic design is set up so that a 1:1 scale drawing will fit perfectly into the Zing Laser Cutter. If we get lucky enough to win the Zing Laser Cutter (hint, hint), we can make a whole class full of these things!

Step 2: Drawings

Okay, I've got my 3D model made. Now it's time to put it on paper and let the students have at it. Some might argue why I didn't have the students do the design. Quick answer - time- or the lack there of. Maybe I'll have them design it next year, but with the end of the school year closing in like a freight train, there just wasn't enough time this year.

So with instructions in hand and cardboard boxes collected, it's time to unleash the hounds, er students.

A quick safety reminder: no running with scissors and don't try to catch dropped cutting knifes. With that said, off we go!

Step 1. Cut out the profiles from the plans (note we even recycled the scraps)

Step 3: Sub-assemblies

Step2. Once the profiles have been cut out, glue each sub-assembly piece together. Elmer's glue works great! Use packing tape or drafting tape to hold the pieces together while they dry.

Step 3. Place the sub-assemblies on some scrap paper so that any glue that squeezes out in the next step will not dry your piece to the desk!

Step 4. Make a paper book sandwich. After gluing the assemblies and while they're still wet, sandwich the sub-assemblies between two pieces of paper and place a heavy book on top to gentle squeeze the pieces together. Let the sub-assemblies dry overnight.

Step 4: Assemblies

Step 5. Okay. So you let all of your sub-assemblies dry overnight, right? Good. Now you can start on the main frame assembly. Glue the two centers to the outside of the middle vertical support "stop", using the slot to align the centers. The throwing arm should move freely and have about 1/16" space between the arm and the two center sections.

Step 5: Final Steps

Step 6. GLUE AND TAPE THE TOP BAR IN PLACE BEFORE THE GLUE DRIES FROM THE LAST STEP.

**THIS IS YOUR LAST CHANCE TO MAKE SURE TO KEEP THE ASSEMBLY SQUARE. ADD TAPE AS NEEDED TO KEEP THE CATAPULT SQUARE**

MAKE SURE THE THROWING ARM FREELY MOVES BEFORE LETTING THE ASSEMBLY DRY OVERNIGHT.

NOW GO AWAY AND PLAY OUTSIDE. DON'T MESS WITH IT!

LET THE ASSEMBLY DRY OVERNIGHT.

Step 6: Final Steps

Step 7. Okay. So now everything is dry. It's time to find a good rubber band (thank goodness our cleaning staff uses large red rubber bands to hold plastic bags on the trash cans!) Now that I've got a strong rubber band, let's throw something! We started off using plastic soda bottle caps as ammo (keeping with the recycled theme and how accessible they are around here). Unfortunately, the bottle caps don't fly very well. So, a quick trip to the local sporting goods store and $4.99 later, I have 10 plastic practice golf balls. Guess what? They fly great!

Step 7: Fun and Learning

So how did this project benefit the students?

1. The students were able to make an actual prototype from plans (Hands-on project). Some students had never made anything from a set of plans before.

2. Most of the students had already created plans of machine parts but never had the opportunity to take it to the next step: creating a prototype ( shameful plug for the need for a Zing Laser printer)

3. The students were involved in market research in order to help improve the initial design. After creating the CAD-A-PULT, students in my class were given the opportunity to play with it. I also invited several other classes in the school to try it out. After each student played with the CAD-A-PULT, he/she completed a survey. The survey asked basic questions and gave immediate feedback to my students about how the CAD-A-PULT was viewed by others. From the surveys we were able to discover a couple of short comings in the initial design, which we improved in the next version.

4.Finally a totally recyclable toy made from recycled cardboard. Educational, fun, and green!

Hidden in the construction and play was learning (diabolical I know :-)

Even us teachers had fun.

For free plans, have your teacher send me an email from their school email account and I will email back 1:1 scaled PDF printable drawings. (Note: these plans are set up for an 11"X17" printer, NOT letter size)

Kdjames@Nmtcc.com