subdefined couplings

[Onda]

I would like to know if in solid works 2009 there is a system to consider a coupling under defined (symbol -)such as a pin in a hole or a screw in its headquarters as fully defined.
in proe there is a check that if I remember correctly it is called "allow assumptions" which should be used in these types of couplings.
Is there something similar in solidworks 2009?

Thank you.

wave

 

[marcof]

I would like to know if in solid works 2009 there is a system to consider a coupling under defined (symbol -)such as a pin in a hole or a screw in its headquarters as fully defined.
in proe there is a check that if I remember correctly it is called "allow assumptions" which should be used in these types of couplings.
Is there something similar in solidworks 2009?

Thank you.

wave

you can make it fixed: rmb on the component then click on "fix". for you will behave as fully defined by traditional constraints, but if you make it mobile again it is easy to walk around the screen. eyes that with this system the presence of a part of the constraints then risks creating errors in the case of changes of the reference geometry to which the part leans because the component cannot move consistently with the constraints you imposed, being precisely fixed.
"allow assumptions" of pro-and what does it do specifically?

 

[Onda]

if the fixed (ground) then the other couplings are useless and sometimes harmful.

the "allow assumptions" makes the part inserted in the axieme be considered completely defined even if it is free to rotate around its axis of symmetry.
For example, if I insert a screw at the head, the orientation of the hexagon on the head of the screw does not matter. But in sw if I do not define the orientation the part appears to me as subdefined, symbol (-). in proe, to prevent the part being considered indefinite, there is the "allow assumptions".

Indeed, it is not for anything but to have a clear vision if a whole really has underdefinite parts and needs further constraints or the underdefinite parts have been voluntarily left such.

 

[marcof]

if the fixed (ground) then the other couplings are useless and sometimes harmful.

In fact, I think I never used the fix if not for some verification on the flight of cinematisms.

the "allow assumptions" makes the part inserted in the axieme be considered completely defined even if it is free to rotate around its axis of symmetry.

Okay, got it. It is a pure formal question, because, however, in life: , there are components that have to be subdefined, although software like pro-e probably come the "bolles" to the kernel :hahahahahah: to the only thought, so the ptc invented this elegant command to remove a sign - (or what it is) from the "improve" component:

Hi.

 

[Onda]

Yes, at first sight it is only a formal question.
But sw in the bottom right tells me if a set is underdefinite or not and since a single screw makes me underdefinite it removes the information, in my opinion useful, if there are other components not properly coupled.
Thank you

wave

 

[marcof]

Yes, at first sight it is only a formal question.
But sw in the bottom right tells me if a set is underdefinite or not and since a single screw makes me underdefinite it removes the information, in my opinion useful, if there are other components not properly coupled.
Thank you

wave

even if "allow assumptions" is an excessive poetic license also for a cad as pro-e, the function is certainly useful. :finger:
I told you not? :tongue:

Hi.

 

[erik.bo]

I'm sorry, but I disagree.
I think it is right that the axieme is defined, given that the screws are not defined.
if then one wants to make it totally defined (I don't know what can be useful if you know that only the screws are free to rotate) just add the couplings.
I usually define everything, but not to see the - or for a formal matter, but because I think the aid is lighter to load and manage.

If you think about it as the "subdefined" function etc... you wouldn't have to try to trick him if not what it is for?

 

[Onda]

What it does, and that seems correct to me, is to give the possibility to consider defined those parts that have a cylindrical symmetry, such as screws, pins etc. and that are not bound by the rotation relative to the axis of symmetry.
add a constraint on the rotation of each screw, rivet or pin can be very expensive and absolutely useless to the model. know if the model is underdefinite is very useful. proe solves this problem with a method in my elegant opinion: leaves the choice to the user if to consider the part perfectly defined or if to consider it undefined and to add another bond or even if to leave it undefined.

 

[marcof]

If you think about it as the "subdefined" function etc... you wouldn't have to try to trick him if not what it is for?

I also started in fourth reasoning so, wronging bad.
If you have a piston with the mobile stem and the rest of the cinematic chain that moves accordingly, all interested parties are actually underdefinited from the point of view of academic definitions but in reality they are perfectly defined, because otherwise cinematism would not move. since machinery is usually full of moving parts, here you are pulling with a wheel of components that for the cad are subdefined. in the midst of these 2-300(by hypothesis) , which are so for issues of cinematism, you may have two that are subdefined because you have forgotten a bond or deleted a part that referred to that voincolo. Do you know when you find them? when faced with a particular change those move to their heads and maybe drag behind the geometry of parts molded in top-down just above those two components. the result and it takes you maybe half a day to get everything back.
I believe that if there is not already in the list I will make the enancement request to solidworks. :finger:

Hi.

p.s. I will pray of course that the translator becomes a less definition of the caxxo of "allow assumptions", which is good for a management software of the employment office :biggrin:

 

[Onda]

marcof exactly expressed my motives.
Actually, the "allow assumptions" is my literary translation of "allow assumption", as I used proes in English.

 

[maxopus]

marcof exactly expressed my motives.
Actually, the "allow assumptions" is my literary translation of "allow assumption", as I used proes in English.

the exact translation is: "Permit presumed"

 

[erik.bo]

Okay, so I agree with the history of the film chain. I press that I know him little, but he should have constraints in mecanism, I think they are constraints different from normal ones.
would it not be appropriate to put "real" constraints so that either mecanism is used or not well?
Is it so hard or heavy? sw 2009 or 2010 you know can do that?
Hi.

 

[re_solidworks]

I have always seen "constant presupposes" in proe, then check again if I remember badly. It is a very useful fuinction, which saves matings by aligning usually the main planes that are still not aligned to the plans of the axieme, but there is nothing similar in solidworks, you have to go to add missing coupling.

 

[cacciatorino]

I was colliding against this lack. even if, as a pro/e, it allows to block concentric couplings when required, inter alia in a very fast way (marking a caselline during the insertion of the concentric bond).

I'm supposed to align every screw here, even because otherwise in the table-sided hexagonal screws are bad enough to see, eventually putting the screws in the axes seems to me to be a very long job.

 

[re_solidworks]

I use the mating rules and everything goes with a touch, I never aligned to the touch (the lash fool), but now I try.

 

[cacciatorino]

I was colliding against this lack. even if, as a pro/e, it allows to block concentric couplings when required, inter alia in a very fast way (marking a caselline during the insertion of the concentric bond).

using the "cardial joint" instead of the "concentric" coupling, the piece is stuck to the rotation instead of labile. I don't know if that could cause any other kind of trouble.