ELASTOMER TOOLING & HMI DESIGN
Silicone Keypad Webbing & Compression Mold Shrinkage Calculator
Compute actuation snap ratio, webbing draft angle ($\theta$), stroke travel distance, conductive carbon pill clearance, and mold cavity thermal shrinkage scale factor.
1. Key Webbing & Actuation Inputs
Standard tactile feel: 120g - 250g.
2. Snap Ratio & Mold Dimensions
Tactile Snap Ratio
0.0%
Mold Shrinkage Scale
1.0320×
Contact Pill Gap
0.0 mm
Est. Life Cycles
> 1M
3. Elastomer Dome Cross-Section
Keypad Tooling & Vector Prepress Notes
1. Tactile Snap Ratio Formula: Defined as $\text{Snap Ratio} = \frac{F_1 - F_2}{F_1} \times 100\%$. An optimal tactile click feel requires a snap ratio between $45\%$ and $65\%$. If snap ratio $< 40\%$, the key feels mushy; if $> 70\%$, key return can become sluggish.
2. 3D Compression Mold Scaling: Silicone vulcanization shrinkage ($\alpha \approx 2.5\% - 3.8\%$) requires 1:1 mold cavity DXFs to be scaled up by $S_{\text{mold}} = 1 + \alpha/100$ around the part center of gravity.