Closing two connected arcs

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knightstreet
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Joined: Tue Mar 21, 2023 8:15 am

Closing two connected arcs

Post by knightstreet »

I have drawn two arcs and connected them together using the 'trim edge' tool. I constrain the sketch to start with then I trim it. When I attempt to close the shape, a large number of redundant constraints appear and if I delete them then a number of DoF appear so that the sketch is no longer constrained. Am I doing something wrong here? I've attached the file. I'm trying to do an additive loft to the sketches in the drawing and it requires a closed shape. Any hints would be appreciated.
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NutHelper.FCStd
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papyblaise
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Re: Closing two connected arcs

Post by papyblaise »

I don't see any DOF in any sketch
did you attach the correct file?
knightstreet
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Re: Closing two connected arcs

Post by knightstreet »

I haven’t done the close operation on the file. If you try to close it you get the conflicting constraints. After removing the constraints you get the dof so it seems impossible to close the shape. I think the shape is actually closed anyway.
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papyblaise
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Re: Closing two connected arcs

Post by papyblaise »

trim has a double action: cut to length and join the ends, so all identical operations will be redundant
knightstreet
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Re: Closing two connected arcs

Post by knightstreet »

What's the best way to do what I'm trying to achieve? Is it to constrain the final shape rather than the shapes that precede the trim?
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papyblaise
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Re: Closing two connected arcs

Post by papyblaise »

it's how you feel best
and favor equality constraints instead of reproducing the same dimensions
chrisb
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Re: Closing two connected arcs

Post by chrisb »

knightstreet wrote: Tue Mar 21, 2023 9:05 am I haven’t done the close operation on the file. If you try to close it you get the conflicting constraints. After removing the constraints you get the dof so it seems impossible to close the shape. I think the shape is actually closed anyway.
Your words don't match the file. I see this:
SnipScreenshot-5a551e.png
SnipScreenshot-5a551e.png (15.17 KiB) Viewed 371 times
When I remove one of the constraints which closes this shape, I get this (or the same on the left side) ...
SnipScreenshot-756110.png
SnipScreenshot-756110.png (13.91 KiB) Viewed 371 times
... which shows no issues, just 2 DOF, which is correct.
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knightstreet
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Joined: Tue Mar 21, 2023 8:15 am

Re: Closing two connected arcs

Post by knightstreet »

So the shape is already closed. Why is loft complaining that the shape isn't closed? I should be able to loft the shape with the line right?
knightstreet
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Re: Closing two connected arcs

Post by knightstreet »

Sorry, I've managed it now using additive pipe. I seem to have got confused between loft and pipe. Thanks for looking at the problem.
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Re: Closing two connected arcs

Post by drmacro »

knightstreet wrote: Tue Mar 21, 2023 9:55 am So the shape is already closed. Why is loft complaining that the shape isn't closed? I should be able to loft the shape with the line right?
You are confusing closed with coincident.

The physical proximity of the two vertexes does not constitute coincidence. They must be marked coincident. If they aren't marked coincident, then the solver does not consider the shape closed.

Your other constraints have locked the movement, so you can't see that the vertexes aren't coincident, until you deactivate one of those constriants (as shown by @chrisb )
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