Roberts was educated by the parish priest and early found employment with a boatman on the Ellesmere Canal and later at the local limestone quarries.

[2] By 1816, when defeat of Napoleon had removed the threat of the militia, it was safe for him to return north, he had set up at Manchester as a "turner of plain and eccentric work at No 15 Deans Gate".

Following the success of his power loom, in 1825 he invented a slotting machine to cut keyways in gears and pulleys to fasten them to their shafts.

The tool was reciprocated vertically, and by adopting Maudslay's slide rest principle, he made the work table with a universal movement, both straight line and rotary so that the sides of complex pieces could be machined.

Later he developed the shaping machine, where the cutting tool was reciprocated horizontally over the work, which could be moved in all directions by means of screw-driven slides.

Examples of his machine tools, including the oldest existing metal planer, are in the collections of the National Museum of Science and Industry, London.

Roberts also manufactured and sold sets of stocks and dies to his range of pitches, so other engineers could cut threads on nuts and bolts and other machine parts.

Roberts' inventions had a seminal influence on other machine-tool engineers, including Joseph Whitworth, when he came to Manchester, a decade later.

Whilst there he improved a reed-making machine, originally invented by the American Jeptha Avery Wilkinson, and in 1822 he patented a power loom.

Roberts was a prolific inventor and manufacturer, ranging over turret clock-making, to road vehicles, to iron ship building, to a punching machine, operating on the same system as the Jacquard loom, for punching the rivet holes in the iron plates making up the railway bridge over the river Conwy in North Wales.

According to biographer Richard Leslie Hills, his main contribution was the introduction of improved machine tools without which high standards of accuracy could not be achieved.