thanks for you help ! .
Well actually im only trying to lift 2-3 monitors from the ground to a level. here are the brand Samsung SyncMasterB2030
http://www.samsung.com/in/consumer/pc-peripherals-printer/monitor/desktop-monitior/LS20PUZKF/XL/index.idx?pagetype=prd_detail&tab=specification

They each weight around 4.1 kg.

Hi there, i'm building my first robot with my father and i request your guidance. Please take note that i have small knowledge of electronics. 
I would like to build a robot that could lift some object of lets say a max of 5 kg .

would i need a
arduino uno board
arduino motor shield
some servo
and a motor .

Am i correct ?

ps: is there a way to know how much can a motor lift at what speed?

Thanks for all your help !