Design for assembly cost-down of a 750 W mixer grinder

Saffron's best-selling model is a 750 W mixer grinder with three jars. The base unit, everything except the jars, has 46 parts and takes 410 seconds to assemble on a line in Coimbatore. The bill of materials and labour come to ₹1,980 per unit.

A large UK retailer wants to stock it for South Asian households, but at a landed price that needs a 15% cost cut, about ₹300 per unit. Moving production abroad is not an option. The Coimbatore plant has to make it cheaper by designing it to be easier to build.

The current base has: - a two-piece ABS housing held together by 8 screws; - a separate motor mounting plate with 4 more screws; - a switch bracket, a knob, a knob insert and a spring; - 6 rubber feet, each pressed in by hand; - a cable clamp with 2 screws; - an overload-protector bracket, plus wiring, labels and the motor.

You will run a design for manufacture and assembly (DFMA) study. First you build a baseline with part count, assembly time and a design-efficiency index. Then you find the parts that could be merged or removed, redesign the lower housing in CAD with snap fits, integrated feet and a moulded motor seat, and cost the result including new mould tooling.

You do not need a factory. A teardown of any mixer grinder you can get, or the BOM in the task 1 starter, is enough. The CAD work is done in Fusion 360 student or FreeCAD.

Done looks like a baseline and a redesign analysis side by side, a CAD model of the new lower housing that can be moulded, a cost model in rupees with tooling payback, and a short report for the plant head. The targets are at least 25% fewer parts, at least 30% less assembly time, and ₹300 or more saved per unit.