1.Why not recommend it?
Excessive Weight (Most Fatal Flaw):
The high density of steel makes frames extremely heavy. This significantly reduces the portability and maneuverability of electric scooters, severely contradicting the product's design intent. Users cannot easily lift or carry them.
Lack of Structural Efficiency:
Boxes or frames directly welded from cold-rolled steel have unoptimized cross-sectional shapes. To achieve sufficient strength, thicker materials must be used, further increasing weight. Professional frames, on the other hand, use tubing optimized through finite element analysis (round and irregular shapes), achieving maximum stiffness and strength with minimal material.
Poor Corrosion Resistance:
Ordinary cold-rolled steel is highly susceptible to rust outdoors. While painting or powder coating is possible, everyday impacts and paint chipping can lead to internal corrosion, affecting safety and aesthetics. This is completely different from the comprehensive electrophoretic coating of car bodies.
Fatigue Performance and Safety:
Scooter frames need to withstand complex dynamic loads and vibrations. Stress concentration easily forms at steel welds, potentially leading to fatigue cracks under prolonged vibration, posing a risk of breakage. Professional aluminum alloy frames are mostly integrally molded or use superior welding processes.
2.How to choose the right materials?
Do not use ordinary SPCC cold-rolled sheet.
Instead, use: cold-rolled precision seamless steel pipe or high-strength welded steel pipe (such as ST52). These materials are tubular in shape, possess excellent mechanical properties, and have consistent wall thickness.
3.How to perform rigorous surface treatment?
Best option: Use galvanized steel pipes + powder coating. First, the zinc layer prevents rust, then the powder coating is aesthetically pleasing and wear-resistant.
Secondary option: After phosphating the steel pipes, apply a complete electrophoretic primer and topcoat, mimicking automotive processes.
4.How to conduct professional design and manufacturing?
The design must undergo stress analysis, and key stress-bearing components need to be reinforced.
The welding process must be professional and subject to flaw detection to ensure there are no incomplete welds or cracks.
5.What are the key takeaways and final recommendations?
For personal DIY or prototyping: If you want to experience the building process, you can use ready-made structural steel tubing (square or round) for welding, and then apply rust prevention and painting. However, please be aware that the finished product will be very heavy and only suitable for low-speed, flat surfaces.
For product development or commercial production: Do not hesitate to abandon the idea of using cold-rolled coils to manufacture the frame. The right direction is:
Preferably use aluminum alloy extruded profiles and die-castings; this is the industry standard.
If you are pursuing extremely high performance and a unique appearance, consider high-strength steel tubing (with advanced rust prevention treatment).
Outsource the structural design to an experienced industrial or mechanical design firm; they can provide a comprehensive solution encompassing materials, processes, and stress analysis.