Hello,

I've started learning how to use open modelica and I'm looking through the examples and trying to build them by myself to try to understand them and I have a few questions concerning using the multibody library.  I've got the example "SpringWithMass" to compile and run, but when I try to re-create it in OMEdit it didn't  quite run the first time.

I looked at the error from why it didn't solve and looked properties of the body in my simulation and I have:

Modelica.Mechanics.MultiBody.Parts.Body body1(m = 1, angles_fixed = true, r_CM = {0, 0, 0}, w_0_fixed = true, animation = false) annotation(Placement(visible = true, transformation(origin = {20, 40}, extent = {{-10, -10}, {10, 10}}, rotation = 90)));

and the example has the following:

Modelica.Mechanics.MultiBody.Parts.Body body(r_0(start = {0, -0.3, 0}, each fixed = true), v_0(each fixed = true), angles_fixed = true, w_0_fixed = true, r_CM = {0, 0, 0}, m = 1) annotation(Placement(transformation(origin = {10, -10}, extent = {{-10, -10}, {10, 10}}, rotation = 270)));

If I change my model to have "r_0(start = {0, -0.3, 0}, each fixed = true)" then it solves.  Which I think gives it an initial guess for r_0 to fix the solver error about the distance between the origin of frame_a and the origin of frame_b

Is there a way to set these variables in the body dialog box?  If I try to enter "r_0(start = {0, -0.3, 0}, each fixed = true)" into the modifiers tab of body I get errors that it isn't formatted right.  I tried some formatting combinations to try and get it to accept it but I couldn't figure out the correct format.

I got the model to solve by manually changing the model in the Text View.  Is this the only way to do it?  Is there another way I can make this change?

Thanks,
Mark