Gas Spring - Dynamic Block Stretching Help

[Anonymous]

I want to made one DYNAMIC block for each different size gas spring, and be able to stretch the rod end to the desired stroke...for example: CU4-420-006, CU4 420-010, etc, will all be in one block, with a drop down selection to select the desired size, as well as being able to stretch the rod end. I have tried to figure it out but the stretch point moves if you switch between different sizes instead of staying at the base point which was selected.

[Anonymous]

Forgot to add file for reference of what I have done...

[Libbya]

I'm still a little unclear what the issue is.  Maybe draw a couple examples within the file showing both how you would like it to behave and how its current behavior differs from desired.

I think you could do all of it without any visibility states and instead use a Block Properties Table.  

[ojuris]

could you use 1 linear parameter for all visibilities not one for each of them?

and you don't use linear parameters in the right way. If you want stretch in 1 direction then where you need blue arrow there must be second point of linear parameter. For your block go in block edit mode, select linear parameter and in Properties window switch Number of grips to 1. You'll see that wrong arrow is switching off for Linear parameter

[Libbya · Accepted solution]

This might help.  

[Libbya]

After posting that last screencast I realized I didn't account for the middle stretch point.  Here's an updated version that picks up where the last screencast left off.

[Anonymous]

Thanks for the help! one question for you...after i complete the block for some reason the label for the gas spring does not show up in the model space.  If you know what might be causing that it would be greatly appreciated.

[Libbya]

It's always easier to diagnose an issue if you post the block.  Most likely cause is that you did not run ATTSYNC.  ATTSYNC is required for any attribute changes within a block definition to show up in model space in existing block insertions.  New insertions will include the new attribute definitions.

[Anonymous]

Yep that was it...final question (two part)...i attached file this time.

1) How can i make it so the centerline stays equidistant from both ends of the spring for each size

2) How can i add another stretch command to be able to control the length of the screw

@Libbya

[Libbya]

I'm not sure what you are calling the 'spring' and so I am consequently unsure how to keep the centerline equidistant. 

I'm also not sure what you are calling the 'screw' so again unsure how to advise.

I'll make my best guesses to both.    

[Anonymous]

I Have another question for you...i attached my block file.  I want to have one dynamic block that encompasses two different sized springs in the block, and be able to stretch both like listed above.

[Libbya]

I would add the visibility parameter to the block properties table as the first column so you select that first.  You will also need to either add the new linework to the existing actions, or add new parameters/actions for controlling the new linework and add the appropriate values on the table.  I believe how to do that is all shown in the prior screencasts.  

[Anonymous]

I followed the steps previously described and i am having some issues with the table and the attributes and drop down showing in the model space...i attached my file as well as a snip of what i have listed in the table.

[Libbya]

You cannot leave any of the cells empty.  They all need to have values.  The linework controlled by those cells are not visible when those cells would be active so the actual values are irrelevant, they just can't be empty.  You also need a row on the table to match the as-drawn state of the block, including default attribute values.  You can hit the Audit button on the block properties table to see if there are errors that will prevent it from being displayed when the block is inserted.  You need to pay attention to which direction you make linear parameters, especially if their values are going to be manipulated by a block properties table or lookup.  The base point of the parameter is the first point you select when creating the parameter.  The end point is the second point.  When the parameter value is changed by a BP or Lookup, the basepoint does not change.  The end point changes.  If your action is associated with the base point, then nothing happens because the other end of the parameter is what is changed by the BP value change.  Here's a video showing my diagnostic and repair process.