%lead screw    
%% lead of the screw
v = 1;           % m/s linear speed 
n = 50;          % roational speed in rev/s equal 3000 RPM
L = v/n;         % Lead of the screw
% the lead is 20mm which means we 10mm pitch, 2 start screw
%% Torque requirements
F = 25;          % assuming the load 50 is split between the 2 screws ...
                 % 45 newtons rougly is the weight of a human forarm 
nth = .4;       % average efficenfy rating for the ACME lead screw
T = (F*L)/(2*pi*nth);   %Using the simplified Torque formula we get Torque in N*m
%% critical buckling load
E = 200*10^9;    % young moudule of steel Pa
K = 2;           % K factor for a fixed-free end pillar 
l = .3556;       % length in mm in inches its 14"
d = .007036;     % the inner diamter of the screw this number is place holder till we select a lead screw
I = (pi*d^4)/64; % moment of Inertia
Fcr = (pi^2*E*I)/(K*l)^2;   % force needed to cause buckling in N





