... ratio R2:hand wheel radiusExample, working load 50 kgs,the fast speed,manual operated.Check specification table, 50 kgs with manual ... the smallest model RN-0.5T(pitch=5mm) enough. Fast speed 1/5.Usually,RN-0.5T jack with 5"(125 ... *62.5)=0.8 kgs.Every model has three speed ratios.RN-0.5T,RN-1T,RN-2T,RN- ... 10T and RN-15TFast speed: 1 turn 1 mm travelsMid speed: 1 turn 0.5 mm travelsLow speed: 1 turn 0.25 ...