height adjusting table

Improve design of http://grabcad.com/library/height-adjusting-table-concept, added worm, sector of worm wheel and rocker to provide 400 mm movement. One worm and gear have left hand lead, another worm and gear right hand lead. Lifting table 400 mm by 53 per turn handle, so 7.5 mm per turn. For 2 turns handle per second workbench will lifted on 15 mm. worm gears spec: module: 2 mm; worm: z1=1; Pitch Dia=25mm. outside dia 30 mm; 3.9°. gear: z2 = 212; UPD: hidden inside the lift mechanism. UPD2: added tooth on wheel and "real" worm. Estimated equations: 250 kg in each rod, therefore in rocker have 500 kg, witch gear have around (500/212)/0,8=3 kg on worm (0,8 is efficiency of worm gear pair), with this in mind and pitch dia worm 25 mm (12.5 mm radius), have force from two worms on handle lenght 150 mm equal to 2*3*12.5/150 = 0.5 kg without losses due to friction in roll.