Polar stretch and radius constraint not working

[carl-marcus.ekstrom]

Hi!

This is my first post so bare with me.

I've got this reinforcing bar with polar stretch and a radius constraint. Everything works fine except when I change the radius. I guess the polar parameter can't update. Maybe someone can show me how to do it without constraints?

[Libbya · Accepted solution]

Dynamic parameters/actions often do not play well with constraints.  In this case I would recommend eliminating the polar parameter and replacing it with an angular constraint and an aligned constraint for similar functionality.  

[carl-marcus.ekstrom]

Hi, thanks for the reply. I've got your solution working before. Isn't it possible to explode everything, use a polar stretch and have a local scale and polar stretch of the arc (w/ predef sizes)?

I guess the difficult thing is that the main polar stretch doesn't run through the center of the arc. 

[j.palmeL29YX]

Tell us what you want to achieve (not which ways you think HOW to do it). What should the block be able to do, i.e. which values do you want to be able to change and how do you want to change the values (Using the Properties window or also using grips. Do you urgently need grips?).

Where do you need a "fix" point: At the intersection of the two lines or at the center of the arc or ...?

Can you please specify the requirements for the block as precise as possible? What do you need urgently and what would be nice ...

[hwalker]

@carl-marcus.ekstrom is I believe trying to make SHAPE CODE 14. See the image below. This is why the polar stretch is needed and the radius constraint is needed. As you can see the angle of the bar will change. However if the width of the bar is below 20 the radius needs to be 2 x Width however if the bar is 20 or above the radius needs to be 3.5 x Width

[carl-marcus.ekstrom]

Hi, yes you are correct I'm making a library of the reinforcing bars in a standard(I'm using the Swedish one, they are just named slightly different).

Ideally something like this:

[carl-marcus.ekstrom]

Hi!

@j.palmeL29YX 

I now know what I would like. (Sorry for the undetermination)

[j.palmeL29YX]

What doesn't work at the solution posted by @Libbya  >>above<< for you? I'd do it nearly the same way. 

[hwalker]

The radius shouldn't move from it's position, it should stay where it is. The "Legs" of the reinforcement are the ones which need to stretch

[carl-marcus.ekstrom]

Hi, the solution from Libbya works. I had the same solution before I started working with polar stretch. I now scrapped that idea and now reverted back to the original solution.

I now try to get cover thickness working aswell, do you have any suggestions?

[carl-marcus.ekstrom]

Correct, the legs need to stretch when changing the radius (that works with aligned param+radius param)

[j.palmeL29YX · Accepted solution]

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@carl-marcus.ekstrom wrote:

I now try to get cover thickness working aswell, do you have any suggestions?

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If I understand you right, you need something as >>shown here<<. (The red lines are the "given " geometry. Now you can place the block and adjust as needed. )

If yes, have a look at the attached dwg.

[carl-marcus.ekstrom]

Almost exactly what I wanted:)! Added the ability to stretch and rotate the first leg as well.