Degrees of Freedom Indicator????
Degrees of Freedom Indicator????
(OP)
Exists???? Some of my components show the (-) sign, and as I understand, it means that they are not fully constrained, but I try to drag it to know wich is the constraint that is miss and they just don't move anyway... so, I don't know why is that symbol shown... THnks
Adi Corrales Magallanes
Centro de Ingenieria y Desarrollo Industrial
Queretaro, Mexico






RE: Degrees of Freedom Indicator????
"But what... is it good for?"
Engineer at the Advanced Computing Systems Division of IBM, 1968, commenting on the microchip.
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?
RE: Degrees of Freedom Indicator????
Adi Corrales Magallanes
Centro de Ingenieria y Desarrollo Industrial
Queretaro, Mexico
RE: Degrees of Freedom Indicator????
Chris
RE: Degrees of Freedom Indicator????
RE: Degrees of Freedom Indicator????
Regards,
Scott Baugh, CSWP
3DVision Technologies
http://www.3dvisiontech.com
http://www.scottjbaugh.com
FAQ731-376
FAQ559-716 - SW Fora Users
RE: Degrees of Freedom Indicator????
Well, going back to my question... I don't mind have the symbol (-) in my parts but I really want to know if they could move or not, because, if I share my design, my coworkers could move something that it supposed not to move, so... That's why I need to know if there is something like the degress of freedom indicator, in order to know if the part CAN REALLY move.
Adi Corrales Magallanes
Centro de Ingenieria y Desarrollo Industrial
Queretaro, Mexico
RE: Degrees of Freedom Indicator????
I don't think there is a Degree of freedom indicator.
Regards,
Scott Baugh, CSWP
3DVision Technologies
http://www.3dvisiontech.com
http://www.scottjbaugh.com
FAQ731-376
FAQ559-716 - SW Fora Users
RE: Degrees of Freedom Indicator????
"But what... is it good for?"
Engineer at the Advanced Computing Systems Division of IBM, 1968, commenting on the microchip.
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?
RE: Degrees of Freedom Indicator????
RE: Degrees of Freedom Indicator????
You have 6 DOF: 3 translactions (along X, Y and Z) and 3 rotations (around X, Y and Z).
Examples:
When fix a part, you have all 6 DOF constarained.
When you mate 2 faces to be coincident, you are constraining 1 translaction (normal to the faces) and 2 rotations (around 2 normal axes that lay on face plane). So you will need to add mates to fix 2 translactions and 1 rotation
When you mate 2 faces to be parallel (notice the difference), you are constraining 2 rotations (around 2 normal axes that lay on face plane). So you will need to add mates to fix 3 translactions and 1 rotation
When you mate 2 faces to be concentric, you are constraining 2 translactions (2 axis normal to cilinder axe) and 2 rotations (around those 2 normal axes). So you will need to add mates to fix 1 translaction (alog cylinder axe) and 1 rotation (around cylinder axe)
And so on...
If some part is fully constrained, by analysing it's mates, and still have a (-) that's because at least one part that you use for reference (to mate) is not fully constrained. So there's a legacy from parents to children of the uncontrained satus, even if the children have all the necessary mates.
With practice you will have no problem to make this kind of analysis.
Regards
RE: Degrees of Freedom Indicator????
The real question is Will the part could be move for someone else, in some way that I could not find in my work station, though I try to drag, rotate, even overdefine the part and it just don't move, but SW still show me the (-)?
Adi Corrales Magallanes
Centro de Ingenieria y Desarrollo Industrial
Queretaro, Mexico
RE: Degrees of Freedom Indicator????
So if there's a way that this (-) can afect your design, then you should add all the necessary constraints. You should keep a (-) only in cases that will not afect the final result in anyway.
Regards