On-demand manufacturing means ordering custom parts online and having them made to order, in ones or in thousands. The part is cut from a block, printed in layers or moulded. The buyer uploads a design and gets an instant quote.
In the past, ordering a machined part meant phone calls, drawings and weeks of waiting. A buyer had to find a workshop, send the drawing, wait for a quote, and then wait again for the part. Now the whole order can be placed online. The zone has four products. An on-demand manufacturing platform is the website and software that quotes the price and finds a maker. The other three are the three ways a part is made.
A CNC machine cuts the part out of a solid piece of metal or plastic. A 3D printer builds the part up in thin layers. Injection moulding pushes molten plastic into a mould. Each way suits a different job, and the number of parts decides which one to use.
Say a student team in Vellore needs one metal part for a racing car. CNC cutting suits it, because it needs no special tooling. A startup that needs one plastic sample of a casing can print it in a few hours. A company that needs 50,000 plastic caps will pay for a mould, because after that each cap is cheap. As a rough guide, for up to a few hundred parts, CNC cutting or printing is usually cheapest. For several thousand identical plastic parts, moulding is.
The parts must match the drawing within the allowed engineering tolerance, whichever way they are made. The platforms also gain from a network effect: the more workshops a platform has, the more orders it can quote, and the more orders it receives, the more workshops join. India has a large number of small machine shops, so it both supplies parts to these platforms and is a market for Indian platforms of the same kind. The buyer pays the platform, and the platform pays the workshop after keeping a margin. After the part is delivered, the maker may also earn from aftermarket services, such as repeat orders.