Automoblox Accessory

Brief

Automoblox came to our class with a real design challenge. Create an accessory for the T9 truck that brings excitement, learning opportunities, and creativity to kids. The T9 has interchangeable parts already. The brief was, what could be added to extend the play pattern further.

Process

Brainstorm. Each of the four of us listed every accessory idea we could think of. Monster truck mods, fire truck attachments, lift kits, an apocalypse car, a food truck conversion, a tow truck setup, a Kei truck mod kit. We voted on the Kei truck because it fit the brief well (foreign innovation, mix-and-match) and because the proportions of a Kei truck mapped well to the T9 chassis.

Sketches. Each of us did a pencil sketch of the truck with the mods on it. We compared and settled on the visual direction.

Gantt. Four weeks. Brainstorm, sketching, CAD, prototyping, testing, final prototype, final changes, marketing, write-up. The chart kept us on schedule.

CAD. The team built the Kei truck frame in Onshape, then designed each modification (front fenders, back fenders, front lip, side skirts, roll cage, bed). Engineering drawings with full dimensions for each part so anyone could pick up the file and understand it. I contributed to the CAD side and owned the manufacturing decisions downstream.

The last-second print pivot. I was about to slice the truck for the Bambu when I realized the whole thing was not going to fit on the print bed in one piece. We had designed it as a single CAD model. Shrinking the truck to fit would have wrecked the proportions of the toy. The fix had to come from the manufacturing side, not the CAD.

In the moment, we changed course. Split the truck into sections sized for the bed. Added small registration tabs to each split surface so the halves line up the same way every time during assembly. Used magnets at each split to hold the sections together without glue, so a kid can pull the truck apart and snap it back together.

That same magnet system became how the body kit modules attach too. Fenders, lip, roll cage, side skirts, and bed all snap to the chassis with magnets. The mid-project save turned into the feature that made the toy modular.

Magnet assembly. Printed each part separately. Drilled magnet pockets by hand with a small bit at measured positions. Pressed the magnets in. Polarity matters. Aligned every magnet so opposite colors repel and same colors attach.

Result. A modular body kit. Frame plus all the mods, plus a second color variant of the mods. Kids can snap fenders, lip, roll cage, spoiler, and skirts on and off in any combination, or strip the truck down to a clean chassis and add the original T9 wheels. The original T9 stays usable, so we did not remove anything from the existing play pattern, we added to it.

Marketing. Closed the project with a one-sheet ad. Stealth mode (all-black mods), street mode (mixed colors), and track mode (full kit). The brief asked for excitement, learning, and creativity, and the marketing was where we showed how all three landed.

My specific contribution

CAD work alongside the team. Owned the printing on the Bambu, including slicing parts in half where needed for print fit. Hand-drilled all magnet pockets on every printed part. Pressed and aligned all magnets so the polarities matched. The mechanical assembly that turned the CAD into a working toy was mine.

Skills Built

• Group CAD. Splitting one assembly across four people, with named parts and a shared coordinate system so the pieces actually fit when we brought them together.
• Slicer-side decisions. Knowing when to cut a part in half for the printer bed and how to plan the cut so the two halves register cleanly during assembly.
• Hand drilling for fit and finish. Drilling magnet pockets at precise measured positions on a printed part is a different skill from CAD-modeling the pockets. Both are valid. Sometimes the manual approach is the right one.
• Magnetic polarity in design. Magnets only work as intended if every pair is oriented correctly. One wrong polarity and the whole accessory misbehaves.
• Reading a brief from a customer. Automoblox gave us a brief that was about play patterns and learning, not about a part. Solving for the brief instead of for a part was the bigger learning.
• Project management on a four-person team. Gantt chart, role splits, marketing deliverable. The whole team moves together or no one moves.

What I would do differently

Check the part size against the print bed during the CAD stage instead of finding out right before the print. A simple bounding-box check would have caught the issue while we still had time to plan the splits cleanly. The magnet save worked, but it should have been a design choice, not a last-minute rescue.

Also print test pieces for the magnet pocket dimensions before drilling the final parts. A few small test pockets would have caught any drill-position mistakes before they showed up on the finished pieces.