Why Die Casting
The gearbox and main chassis on the Acorn stair lift are manufactured from die-cast aluminium due to its inherent advantages over other materials such as cast iron.

Weight Savings
Aluminium has obvious weight advantages and can weigh half that of cast iron. It has a higher tensile strength and is less brittle!
A stair lift with a lighter main carriage means less wear on moving parts therefore extending the life of the unit. In addition, less power is needed to move the carriage resulting in energy savings also.
Heat Conductivity
Cast iron conducts heat less effectively than aluminium, which is an excellent conductor of heat. This helps to reduce the unit's internal temperatures by conducting heat to the outside air much faster than is possible with cast iron or steel. This makes aluminium an excellent gearbox and motor frame material, evidenced by the fact that motor car gearboxes have been manufactured from aluminium for decades.
Corrosion Resistance
Aluminium, in the vast majority of applications, will exceed the corrosion resistance of cast iron and far exceed that of steel.
Aluminium is covered spontaneously by a thin but effective coating of oxide protecting it from further corrosion. Cast iron continues to corrode throughout the material until its structural capabilities are seriously compromised.
Cast iron is usually specified due to low raw material costs and relative ease of manufacture making it the least expensive of engineering materials. Given the disadvantages of the cast iron material, aiming for a lower cost can mean production of an inferior product.
Accuracy
Aluminium die-castings can be produced with more detail and accuracy than those of cast iron. The advantages can be seen in a quieter and more smoothly running stair lift.
There are very good reasons for aluminium being specified more and more throughout all industries. Over the past 10 years shipments of aluminium castings have increased by nearly 65%.
It is for all these reasons that Acorn uses die-cast aluminium to produce Acorn's leading stair lift.