Monitor Lift

Hello - I'm in the process of trying to replicate the monitor lift to raise and lower my sewing machines - but I need it lift approx 15kg. I can't find the model of motor that Matt used and I'm not sure if a standard DC motor or worm drive is better. The platform will be 28" wide and needs a lift height of 16". Speed is of less concern than noise. I've tried worm drive motors from 160-260 rpm and while all raise and lower the platform, none seem to be strong enough to lift 15kg. Any help is much appreciated.