From Gizmag: Researchers at Siemens have created a new prototype electric motor specifically designed for aircraft that weighs in at just 50 kg (110 lb) and is claimed to produce about 260 kW (348 hp) at just 2,500 RPM. With a quoted power five times greater than any comparable powerplant, the new motor promises enough grunt to get aircraft with take-off weights of up to 1,800 kg (2 ton) off the ground...
... As a result, the new aircraft electric drive system achieves a claimed weight-to-performance ratio of 5 kW per kilogram. This ratio is an exceptional figure – especially if compared to similarly powerful industrial electric motors used in heavy machinery that produce less than 1 kW per kilogram, or even to more efficient electric motors for vehicles that generate around 2 kW per kilogram... (full article)
Recent servo motors are equipped with the encoder of 20 bits (1,048,576 steps) which has a very fine resolution. Because of this, errors due to the encoder installation accuracy have a huge effect on stopping accuracy.
High resolution. Limited space. Not a problem for our latest miniature encoders that provides precise feedback and is easy to install within smaller-sized applications. Now available in 400 and 500 CPRs. Coming in at about the size of a nickel, we've added our proprietary Opto-ASIC sensor technology and improved quadrature for even greater motion control.
Product Features: 10 resolutions up to 360 CPR, plus new 400 and 500 CPR resolution; 288 configurations available, including single and differential output; Compact form factor
• 0.866 inch (in) / 22.00 millimeter (mm) package outside diameter
• 0.446 in / 11.33 mm package height
• Fits NEMA 8, 11, 14 and 17 motors;
Simple and efficient assembly process
• Four-piece construction
• Push-on hub disk design, patent pending;
100 kilohertz frequency response;
Shafted version up to 0.25 in / 6.25 mm diameter.