GIMBAL Angles Between 2 Parts (Without Int Parts) in CATIA

3D Design Volume Model
1

Hello

I would like to define one system of axes with respect to another with cardan angles (sequence of rotations xyz different from Euler angles zxz).

I would like to be able to define gimbal angles between 2 parts without having to define intermediate parts.

However, in CATIA, there is only a possibility of Euler angles and not Gimbal

Is it possible to define cardan angles between 2 parts without building intermediate parts ?

For the moment, I can build my Cardan angle settings between 2 solids but using intermediate parts. Here is my method:
Part 1 with 1-axis system
Part 2 with 2-axis system and constraints (offset between 2 planes, axis coincidence for axis of rotation, angle for angle of rotation) to define a rotation between the system of axis 2 and the system of axis 1
Part 3 with 3-axis system and constraints (same as before) to define a rotation between the 3-axis system and the 2-axis system
Part 4 with 4-axis system and constraints (same as before) to define a rotation between the 4-axis system and the 3-axis system

I would like to be able to define cardan angles between 2 pieces but without using intermediate pieces (pieces 2 and 3 that I used in the method described above).

Thank you in advance for your help.

2

For Franck, for the record, I had already created a similar but different post:

http://www.lynkoa.com/forum/2d/positionnement-d-un-repere-par-rapport-un-autre-angles-euler-cardan

But the difference is that here I want to define, between a coordinate system 1 of a part 1 and a coordinate system 2 of a part 2, rotations (defined by the cardan angles, alpha rotation angle following x, beta rotation angle following y, gamma rotation angle following z) and that my angles are variable here and between 2 parts (therefore assembly constraints) and not a positioning of a coordinate system by relationship to another within the same room.

3

see this link for CATIA kinematics

 

http://academy.3ds.com/uploads/tx_3dscourseware/1012/Aide-Liaisons-Cinematiques-v1.2.pdf

 

@+

4

Hello

Euler rotation sequence is: Z-0 axis rotation Z-0; X-1 rotation around the new X-1 axis ; Z-2 rotation around the new Z-2  axis not Z-0 rotation; X-0, Z-0

See Euler angle.

What you want to do is X-0 rotation X-0 axis, Y-1 rotation around the new Y-1 axis,  Z-2 rotation around the new Z-2 axis ??

 

 

5

Exactly, Franck.

Here is an illustration to clarify:

1) Alpha angle x0 axis rotation

2) Yalpha Axis Rotation (newly created axis after alpha angle rotation)

3) Zbeta Axis Rotation (newly created axis after beta angle rotation)

6

That's what I understood so the easiest way is to use room -1 as a skeleton for the positioning of room -2

We create in room -1 the point of positioning in space (X;Y coordinates; Z) // to the absolute marker.

Then on this point we create the 4 axis systems corresponding to the return of the absolute axis and the 3 rotations.

It will be sufficient to constrain the part-2 with respect to the last coordinate system created.

7

Great Franck, your answer suits me well.

I applied this method as you can see on the screen print.

I just have one question left to try to keep some order when there are going to be a lot of parts in my assembly.

For the moment, in this method, I constrain the last coordinate system created on my part 1 ( called R2 in the axis coordinate systems of my part 1) with the coordinate system associated with my part 2. Then, I went back to my alpha, beta, gamma angle parameters which were at the level of the axis marks of my part 1 in the product by saying that the alpha, beta, gamma parameters of the product are equal to the alpha, beta gamma parameters of those defined in part 1, at the level of the reference points.

Where it gets complicated is in the case where I have a solid 1 in a cardan connection with a solid 2 which is itself in a universal joint with a solid 3.

Either S1 - Cardan - S2 - Cardan - S3

I would like to make my cardan joints between S1 and S2 and S3 with the same process and bring up the alpha1, beta1, gamma1 parameters of the gimbal 1 and then alpha1, beta1, gamma1 of the gimbal 2 at the assembly level.

To make an assembly a little tidy, I would like to arrange the parameters in groups, a bit like you can do with constraints.

Is it possible to organize product-level parameters into groups?

Otherwise, do you have an idea, to organize the parameters related to each link at the product level?

I hope you understood me. 

8

Hello, to order the parameters in the CATProduct, it's the same as the CATPart.

If you have the KWA workshop there is a cmd to add "parameter sets" (parameter container).

In case you don't have this module, you just have to create a (empty) CATProduct, create a parameter (any), delete this parameter, then copy the "parameter set" and paste it as many times as you want into the CATProduct where you want to organize the parameters.

Then it will be enough to right-click on the parameter(s ) to be moved "Object .....; / Reorder" and point to the "parameter set" where you want to store it(s)

Remember to rename everything, you can use the symbols in the names "Angle_α_1";  "Angle_β_1" ;  "Angle_γ_1".

 

For my part, I prefer to create a skeleton CATPart that posits all the "parts of the assembly" rather than creating in "Solid-1" the position mark of  "Solid-2", then in "Solid-2"  the position mark of  "Solid-3", etc. ( EDIT: I reserve this method to facilitate the positioning of the so-called standard components e.g. on a cylinder I would have the elements that allow to position the cylinder in the assembly (fasteners, clevis, etc) and those that allow to position the accessories of the cylinder (sensors, ball joints, etc))