The SHD gearhead size 14 delivers zero backlash, 1.5 arc-min positional accuracy, and ±5 arc-sec repeatability. The product consists of high-precision harmonicdrive gearing and a high-capacity crossroller bearing. Its outer diameter is 70 mm and is just 17 mm long. The gearhead's rated torque is 33 lb-in. and maximum torque is 310 lb-in. Available gear ratios are 50:1 and 100:1.

HD Systems Inc., 89 Cabot Court, Hauppauge, NY 11788, (800) 231-4374,