Thrust / Force / Torque Proportional to Speed 
'Thrust / Force / Torque Proportional to Speed' formula is a subset of the Load Formula feature. 
Create a thrust / force / torque formula proportional to speed. The table below lists the variables, arithmetic and functions that can be used to create a thrust load formula.
Formula Textbox Rightclick in the formula textbox, and a drop down menu appears listing the profile variables, constants, arithmetic, comparisons and math functions. 

Units for the formula result  
Units for the variables used in the formula

Thrust = 100*VEL 

Thrust = (500/3)*(VEL/MAXVEL) 
Profile Variables  Units  
VEL  Velocity  Linear: m, mm, in Rotary: °, rad, rev 
MAXVEL  Max Velocity in Segment/Move Always a positive value Ie. MAXVEL = Max(Abs(VEL)) in the Segment/Move 
Linear: m/s, mm/s, in/s Rotary: °/s, rad/s, rev/s 
MAXVELCYC  Max Velocity in Cycle/Sequence Always a positive value Ie. MAXVELCYC = Max(Abs(VEL)) in the Cycle/Sequence 
Linear: m/s, mm/s, in/s Rotary: °/s, rad/s, rev/s 
Constants  
PI  Pi (3.14159265358979...)  
Arithmetic  
*  Multiplication  
/  Division  
\  Integer division  
Math Functions  
Abs  Absolute Eg. Abs(1)=1 

Sgn  Sign of a number x>0: Sgn(x)=1, x=0: Sgn(x)=0, x<0: Sgn(x)=1 