Since I think I was not clear with the first question, I'm going to try and explain it better now.
What I'm trying to achieve is a simple example similar to a 3D pendulum. At the time I talked about 2 masses, but one of those was the anchor point, so in fact everything can be done with only one mass. The twist here (in comparison with the simple 3D pendulum) is that besides the gravitational force, the mass is under the effect of: - A force in the x-axis of the mass - A torque about the z-axis of the mass Futhermore, since I'm choosing to describe the system using the (x,y,z) coordinates of the mass (and 3 euler angles) I was trying to add a distance constraint: (r_anchor - r_mass) - L = 0 Here is the jupyter notebook I created in order to define this system: https://nbviewer.jupyter.org/github/ndevelop/sympy_3D_pendulum/blob/master/3D%20pendulum.ipynb Could someone help me understand any mistake I'm making and point me in the right direction? Thanks in advance, Nuno sexta-feira, 5 de Agosto de 2016 às 18:01:39 UTC+1, Nuno escreveu: > > I'm trying to get familiar with the sympy and its uses in obtaining the > equations of motion of multi-body systems. > > In order to test things out I decided to use an example similar to a 3D > pendulum where I have two masses. However the mass that is not fixed has a > force and torque applied to it. So I wanted to have a distance constraint > between the two masses: (r_a - r_b)^2 - L = 0 > > However I'm not sure how I should set this constrain in python/sympy in > order to input it to KanesMethod() > > I'm sorry if this is question is a mess and thanks in advance for any help > -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at https://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/fd9a076b-8aad-4aeb-9765-6fc765d4119a%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.