Knowledge & Community You are here

[Steve Cook]

I’m working on an enclosure for a compact electronic keyboard system, including a weighted key mechanism, and have chosen Aluminium 5083 for all parts due to its corrosion resistance and machinability. My main concern is whether it provides sufficient stiffness to handle the mechanical loads and vibrations from the key mechanism without excessive deflection. Question to the community –would you consider Aluminium 5083 appropriate for this application, or would a material like steel or stainless steel be worth the additional weight and cost for improved rigidity?

0

[Bjorn]

Aluminium 5083 should work well in keeping the weight low for your enclosure. However, if stiffness is more critical, steel would provide better rigidity, though it would significantly increase the weight, by 2 or 3 times.

Alternatively, a hybrid design—using Aluminium for the outer panels and plated mild steel for some internal structural elements – could strike a good balance between weight and stiffness.

0

[ovidiu.baciu]

If you want a stronger aluminum, you could consider also the 6XXX series: 6061, 6082.

Depending on the corrosion environment, another good choice would be 7075 with a good coating. For example, in salt environments, the 7075 is not a good choice due to Cu content of ~2%.

0

[欣雨杨]

5083 aluminum has lower stiffness (elastic modulus ~70 GPa) compared to steel (~200 GPa), but offers advantages in weight, corrosion resistance, and machinability. For compact keyboards:

Prioritize structural design validation: Topology optimization (e.g., reinforcing ribs, localized thickening) can compensate for stiffness and typically meet low-frequency mechanical load requirements.
Vibration considerations: Use steel if key actuation frequencies align with the structure’s natural frequencies (due to steel’s higher damping), otherwise aluminum with vibration-damping pads suffices.
Alternatives: 6061-T6 aluminum (slightly better strength/stiffness) or locally embedded steel bushings to balance performance and weight.
Conclusion: 5083 aluminum is generally viable with optimized design. Steel is only necessary for high-frequency/high-impact loads. Finite element modal analysis is recommended for verification.

0

[Jean90]

You can achieve a lot of stiffness by deep drawing the main enclosure component and forming ribs in the process. The weight gain from any steel stiffeners will be considerable if all the stiffness comes from flat steel parts, so even if you do use an Aluminium cosmetic skin and steel structure, you should likely look at folding the steel to offer some depth and rigidity.

0

[Bjorn]

Agreed, though if it’s reaching the point where, if the Aluminium is purely cosmetic, it might be better to simplify and use a stainless steel pressing for the main enclosure – you’d get all of the corrosion resistance of the Aluminium and more – and back to a simpler structure. It’ll be a finely balanced manufacturing cost decision that will come down to tooling costs and component count.

0