Eng-Tips is the largest engineering community on the Internet
Intelligent Work Forums for Engineering Professionals
-
Congratulations waross on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!
Spring compresion in motion simulation in NX5 3
- Thread starter akrah
- Start date
-
1
- #2
Easily actually! You need a spring defined in such a way that a length parameter will affect its geometry. A simple helix does this. If you want to use the same spring more than once in the same file then you can use deformable parts.
The best way to illustrate is with a simple example. I have attached a file and there is an animation set up inside this so that you can quickly rock the thing back and forth to see the spring length change.
Let us know if there is anything about this that you can't understand from the example.
Best Regards
Hudson
www.jamb.com.au
Nil Desperandum illegitimi non carborundum
The best way to illustrate is with a simple example. I have attached a file and there is an animation set up inside this so that you can quickly rock the thing back and forth to see the spring length change.
Let us know if there is anything about this that you can't understand from the example.
Best Regards
Hudson
www.jamb.com.au
Nil Desperandum illegitimi non carborundum
- Thread starter
- #3
Thank you Hudson,
I am, however, still not able to succeed in animating the deformation. I can rotate the rocker and move the seat in your animation set up, but can not deform the spring even though I can see in assembly that you defined the spring as deformable.
Hudson,
Could it be too much to ask whether it is possible for you to tell me step by step what to do in order to animate spring deformation since I am new in motion animation.
I am, however, still not able to succeed in animating the deformation. I can rotate the rocker and move the seat in your animation set up, but can not deform the spring even though I can see in assembly that you defined the spring as deformable.
Hudson,
Could it be too much to ask whether it is possible for you to tell me step by step what to do in order to animate spring deformation since I am new in motion animation.
Please turn off partial loading and try again it will most likely simply be that the springs are not fully loaded. Make sure for example that you're not loading faceted bodies by default.
If you can get it working it will be better as I undertook to model the thing simply on the basis that it is less time consuming than constructing an explanation. I'd also add that nothing in the explanation I'd give you would make any difference to why it would not be working as delivered.
If on the other hand you've remodelled the spring yourself and don't know how to set up the deformable part then look harder again at mine. What you'll find is that all the features in the model were added to the deformation but the only expression used was the one called "length".
Best Regards
Hudson
www.jamb.com.au
Nil Desperandum illegitimi non carborundum
If you can get it working it will be better as I undertook to model the thing simply on the basis that it is less time consuming than constructing an explanation. I'd also add that nothing in the explanation I'd give you would make any difference to why it would not be working as delivered.
If on the other hand you've remodelled the spring yourself and don't know how to set up the deformable part then look harder again at mine. What you'll find is that all the features in the model were added to the deformation but the only expression used was the one called "length".
Best Regards
Hudson
www.jamb.com.au
Nil Desperandum illegitimi non carborundum
Hi Hudson & akrah
This is similar to my question on the torsion spring I posted a few days ago.
I tried the assembly that Hudson sent through but when I clicked to open it all of the constituent parts were left with white square icons and didn't load, even though I saved all the parts in the same folder.
Looks as if the assembly file defaults to the drive where they were created. I loaded them in manually but then nothing was constrained. The deform options are greyed out too so can't be modified.
I did get it to work when I created a brand new & fully constrained assembly.
Is there some good explanation of the deform command somewhere? the five steps to creating the deform are complicated to understand especially on the references (4th step) where its hard to understand what is actually being asked for. If you skip this step completely the command still works OK....
I never managed to get a torsion spring with two bent legs to deform correctly; there is always a small portion of the extrude on one of the legs left behind.
Best regards
This is similar to my question on the torsion spring I posted a few days ago.
I tried the assembly that Hudson sent through but when I clicked to open it all of the constituent parts were left with white square icons and didn't load, even though I saved all the parts in the same folder.
Looks as if the assembly file defaults to the drive where they were created. I loaded them in manually but then nothing was constrained. The deform options are greyed out too so can't be modified.
I did get it to work when I created a brand new & fully constrained assembly.
Is there some good explanation of the deform command somewhere? the five steps to creating the deform are complicated to understand especially on the references (4th step) where its hard to understand what is actually being asked for. If you skip this step completely the command still works OK....
I never managed to get a torsion spring with two bent legs to deform correctly; there is always a small portion of the extrude on one of the legs left behind.
Best regards
RobLN,
I made the assembly with mating conditions if you want to use constraints in can be done also. Just for reference by the way what version of NX were you running?
Best Regards
Hudson
www.jamb.com.au
Nil Desperandum illegitimi non carborundum
I made the assembly with mating conditions if you want to use constraints in can be done also. Just for reference by the way what version of NX were you running?
Best Regards
Hudson
www.jamb.com.au
Nil Desperandum illegitimi non carborundum
Sorry Hudson, you've lost me there. I don't know how mating constraints work. Are they part of the Motion Simulation program? How do you insert one?
I know that in Solid Edge there was a 'contraint tool' called mate.
My NX is version 5.0.4.1
I know that in Solid Edge there was a 'contraint tool' called mate.
My NX is version 5.0.4.1
-
1
- #8
doc1955
Aerospace
- Mar 14, 2008
- 68
- 0
- 0
I made a little movie to try and help.
I looked at the constraints and turned one off so I could move part. I also point out the measure expressions that control spring. As far as the deform expression grayed out go ahead and make it constant and you will be able to change they are grayed out because they are both controlled by the expressions I point out. Hope this helps.
Doc
I looked at the constraints and turned one off so I could move part. I also point out the measure expressions that control spring. As far as the deform expression grayed out go ahead and make it constant and you will be able to change they are grayed out because they are both controlled by the expressions I point out. Hope this helps.
Doc
Thanks for your efforts. Is seems my confusion about mating constraints / Assembly constraints stems from the fact that I don't seem to have access to any of those commands in my version of the NX software.
I did a search on the command finder and got the following results:
1. 'Reposition component': 'This command is not available'
2. 'mate Component'or 'mating conditions': 'This command is not available'
Some of the options for example the Measurements tool seem only to be available in the 'Tolerance stackup Validation application' - whatever that is
.
If I try to run this from Analysis>Tolerance Stackup Validation I get an error that there is no library for the application. Looks like I don't have that bit of the software. I will be talking to our NX administrator later to see if I can get access to those part of NX.
Best regards.
I did a search on the command finder and got the following results:
1. 'Reposition component': 'This command is not available'
2. 'mate Component'or 'mating conditions': 'This command is not available'
Some of the options for example the Measurements tool seem only to be available in the 'Tolerance stackup Validation application' - whatever that is
. If I try to run this from Analysis>Tolerance Stackup Validation I get an error that there is no library for the application. Looks like I don't have that bit of the software. I will be talking to our NX administrator later to see if I can get access to those part of NX.
Best regards.
doc1955
Aerospace
- Mar 14, 2008
- 68
- 0
- 0
Do you hava assemblies turned on?
Click your start and make sure you have a check mark next to assemblies. If you don't you will not have any mate orany of the commands mentioned.
Doc
Click your start and make sure you have a check mark next to assemblies. If you don't you will not have any mate orany of the commands mentioned.
Doc
-
1
- #11
By all means try this copy which uses positioning constraints rather than mating conditions.
NX-5 still uses the old reposition component, and the whole mating conditions versus positioning constraints thing seems to remain fairly optional for now.
Best Regards
Hudson
www.jamb.com.au
Nil Desperandum illegitimi non carborundum
NX-5 still uses the old reposition component, and the whole mating conditions versus positioning constraints thing seems to remain fairly optional for now.
Best Regards
Hudson
www.jamb.com.au
Nil Desperandum illegitimi non carborundum
doc1955
Aerospace
- Mar 14, 2008
- 68
- 0
- 0
Your roll dosen't take away or add commands. They control only tool bars and lay out, the commands will still be available you just don't have a tool bar.
Doc
Doc
Hello,
Im also having big troubles with springs motion. I know how to define them as deformable geometry so they update in assembly, but I'd like them to animate with the rest of the mechanism in Motion Simulation module. Is it possible?
Best Regards, Koen
Im also having big troubles with springs motion. I know how to define them as deformable geometry so they update in assembly, but I'd like them to animate with the rest of the mechanism in Motion Simulation module. Is it possible?
Best Regards, Koen
- Thread starter
- #17
Hi,
As Hudson888 said above, yes it is possible although I am not able to animate the compression of the spring in motion animation despite the fact that Hudson and Doc explained it.
I can deform the spring in the assembly by going to Assembly--component-- deform part, but not the way you showed in the movie, Doc1995.
I attach a simple assembly. Can anybody tell me what I am doing wrong or what I am missing in order to animate the compression of the spring in motion animation?
As Hudson888 said above, yes it is possible although I am not able to animate the compression of the spring in motion animation despite the fact that Hudson and Doc explained it.
I can deform the spring in the assembly by going to Assembly--component-- deform part, but not the way you showed in the movie, Doc1995.
I attach a simple assembly. Can anybody tell me what I am doing wrong or what I am missing in order to animate the compression of the spring in motion animation?
There is a simple animation set up in the file. I assigned some materials and output the video for you.
I can only do so much for you. The deformable parts dialog is kind of a one shot deal since it doesn't allow you to analyse very easily. Do this using my spring. In the first screen you give the deformation a name, in the second you select all the features and move them into the right hand panel, and in the third you select the expression length and move it into the right panel then click finish to complete the task.
When you add the spring to any assembly henceforth it will ask for a value for the length expression. If you have the rest of the assembly set up properly you should be able to set the length to a previously defined length measurement expression. Provided that the spring is located in the base in the assembly articulating the rocker will have the effect of moving the seats (or vice versa) then as the distance expression changes so will the spring length. It simply gives the appearance of being a mechanism because it is now programmed to behave as one.
I suggest to you that as you go you perhaps ought hit the F1 key and read at each stage the documentation associated with steps you may be unfamiliar with. I have made a small model as knowledge rich as I could so that there are by now quite a few techniques used which I really don't think would be better explained at length since there are a largish number of steps involved. If you de-construct my model faithfully you ought get the same result.
Best Regards
Hudson
www.jamb.com.au
Nil Desperandum illegitimi non carborundum
I can only do so much for you. The deformable parts dialog is kind of a one shot deal since it doesn't allow you to analyse very easily. Do this using my spring. In the first screen you give the deformation a name, in the second you select all the features and move them into the right hand panel, and in the third you select the expression length and move it into the right panel then click finish to complete the task.
When you add the spring to any assembly henceforth it will ask for a value for the length expression. If you have the rest of the assembly set up properly you should be able to set the length to a previously defined length measurement expression. Provided that the spring is located in the base in the assembly articulating the rocker will have the effect of moving the seats (or vice versa) then as the distance expression changes so will the spring length. It simply gives the appearance of being a mechanism because it is now programmed to behave as one.
I suggest to you that as you go you perhaps ought hit the F1 key and read at each stage the documentation associated with steps you may be unfamiliar with. I have made a small model as knowledge rich as I could so that there are by now quite a few techniques used which I really don't think would be better explained at length since there are a largish number of steps involved. If you de-construct my model faithfully you ought get the same result.
Best Regards
Hudson
www.jamb.com.au
Nil Desperandum illegitimi non carborundum
akrah,
I have had a look at your example. What I'm seeing is the the expression L_7 for the deformable length of the spring is locked and you can't edit it to change it to the expression as I did. That seems to be because you selected positioning constraints rather than mating conditions to be used in you customer defaults. Mine works because I started out using mating.
John, if your reading this and I'm correct I suppose it represents an ER for positioning constraints to at least support the same capability that mating could provide. Should I be wrong I'd be overjoyed to know how I might otherwise go about this task.
Best Regards
Hudson
www.jamb.com.au
Nil Desperandum illegitimi non carborundum
I have had a look at your example. What I'm seeing is the the expression L_7 for the deformable length of the spring is locked and you can't edit it to change it to the expression as I did. That seems to be because you selected positioning constraints rather than mating conditions to be used in you customer defaults. Mine works because I started out using mating.
John, if your reading this and I'm correct I suppose it represents an ER for positioning constraints to at least support the same capability that mating could provide. Should I be wrong I'd be overjoyed to know how I might otherwise go about this task.
Best Regards
Hudson
www.jamb.com.au
Nil Desperandum illegitimi non carborundum
- Status
