Hello and welcome to new post in which we discuss one of my plastic part failure studies answering the question: Why did the toy helicopter rotor blades keep breaking?
Ever had a toy fail at the worst possible moment? That’s what happened with a rescue helicopter toy—kids reported the rotor blades snapping during “harder” rescue missions, always at the same spot. As someone who knows the pain of ordering spare parts, I had to dig deeper!
Here’s what I found:
Root Cause: The blades, made from ABS, consistently broke at the injection point—a natural weak spot. When force was applied (think: enthusiastic play!), stress concentrated here, causing failure.
Why Always the Same Spot? The injection point acts like a weak link in a fixed beam. Too much stress, and snap—it breaks right there (Figure 1).
 |
| Figure 1: Broken toy helicopter blade - injection molding point as root cause identified. |
How to Fix It?
1. Move the Injection Point: Shift it to the blade’s center using a conical gate, ensuring even filling and less stress (Figure 2).
 |
| Figure 2: Moving the injection point to the center allowing for even filling of both blade sides. |
2. Upgrade the Material: Switch to glass fiber reinforced ABS, increasing the needed force to break the rotor blade by 43% (Figure 3)!
 |
| Figure 3: Changing from ABS to ABS+GF10 increases the needed force to break the blade. |
3. Combine Both Approaches: For maximum durability.
This is a great reminder: optimal injection molded parts require attention to all five points of the Polymer Product Pentagram—Part Design, Material Selection, Mold Design, Machine Selection, and Molding Process.
Have you faced similar failures? Let’s connect here and share solutions!
Thanks for reading & #findoutaboutplastics
Greetings,
No comments:
Post a Comment