Fillet BRep_API: command not done

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Stou
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Re: Fillet BRep_API: command not done

Postby Stou » Tue Jan 22, 2019 8:10 pm

I can't see what is not contrained in that sketch.

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openBrain
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Re: Fillet BRep_API: command not done

Postby openBrain » Tue Jan 22, 2019 8:35 pm

Will have a deeper look, but usually what is missing is the absolute positioning. :)
It means that you have to lock the sketch versus the origin or versus external geometry. ;)
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Re: Fillet BRep_API: command not done

Postby openBrain » Tue Jan 22, 2019 8:38 pm

At first view, your spline is not constrained at all. There are missing coincident constraints between bspline endpoints and lines to which it is linked.
Also the control point of the spline is loose.

EDIT : also the lines are not constrained to be perpendicular

EDIT 2 : OK, let's summarize what are the missing constraints :
* Coincidence between the spline endpoints and the lines endpoints
* Angles between adjacent lines (perpendicular or a particular angle)
* Relative positioning of the spline control point (central one)
* Diameter/radius of the spline control circles (blue ones)
* Absolute positioning of the sketch (lots of way to achieve this, relatively to origin or other parts)

Hope this helps
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Stou
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Re: Fillet BRep_API: command not done

Postby Stou » Tue Jan 22, 2019 10:44 pm

Ok, thanks for the constrain info. I'm starting to be more comfortable with the constrain. It look like a mess but it is full contrain. But now when I Extrude it, it make it like an open object. I looked with the zoom and that's the case. The shape is open on both end of the spline. I can't find how to connect the spline with the lines. I tried many things and look arouns the forum but didn't found how to do it in Sketch.

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chrisb
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Re: Fillet BRep_API: command not done

Postby chrisb » Wed Jan 23, 2019 8:39 am

chrisb wrote:
Tue Jan 22, 2019 11:58 am
Things would be clearer if "Apply" was renamed to "Create" and "Ok" to "Create + Close".
In Helix panel there are only Create+Close buttons. It's very clear what happens.
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Stou
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Re: Fillet BRep_API: command not done

Postby Stou » Wed Jan 23, 2019 3:39 pm

I finally found a way to have a close shape in a Sketch in order to do extrusion like I need to do the cut for the cable. If I use grid snap it work but if I do the same sketch without snap, the shape is not close.

But now I'm still strugling with the fillet. I need to do a fillet on the front part of the lever (green line on the picture) and I have not succeeded yet. Or maybe there's another way than fillet to do it?

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meme2704
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Re: Fillet BRep_API: command not done

Postby meme2704 » Wed Jan 23, 2019 4:13 pm

Hi
How do you want the extrusion to work with an open sketch
Why make a B-spline when a radius is enough and more saft
At home, a 1.5mm net works
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embrayage.PNG
embrayage.PNG (82.21 KiB) Viewed 66 times
openBrain
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Re: Fillet BRep_API: command not done

Postby openBrain » Wed Jan 23, 2019 6:22 pm

Stou wrote:
Wed Jan 23, 2019 3:39 pm
I finally found a way to have a close shape in a Sketch in order to do extrusion like I need to do the cut for the cable. If I use grid snap it work but if I do the same sketch without snap, the shape is not close.
As I former stated, you need to use "coincident" constraint between the spline endpoints and the line endpoints to which they are attached. ;)
https://www.freecadweb.org/wiki/Sketche ... onstraints
But now I'm still strugling with the fillet. I need to do a fillet on the front part of the lever (green line on the picture) and I have not succeeded yet. Or maybe there's another way than fillet to do it?
Better you provide the FCstd file and tell us what fillet radius you would use. So we can figure out what's going wrong. :)
Stou wrote:
Tue Jan 22, 2019 10:44 pm
Ok, thanks for the constrain info. I'm starting to be more comfortable with the constrain. It look like a mess but it is full contrain.
According the screenshots, I think your constraint usage still can be improved ;) :D Despite GeneFC would probably love it as it is :lol: :lol:
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Re: Fillet BRep_API: command not done

Postby chrisb » Wed Jan 23, 2019 7:12 pm

As indicated above, you should try to interrupt the automatic extension of the fillet along tangents by avoiding the very small radiuses. Make them to sharp corners and add fillets there later.
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Stou
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Re: Fillet BRep_API: command not done

Postby Stou » Wed Jan 23, 2019 8:09 pm

meme2704 wrote:
Wed Jan 23, 2019 4:13 pm
Hi
How do you want the extrusion to work with an open sketch
Why make a B-spline when a radius is enough and more saft
At home, a 1.5mm net works
I know it can't work with open sketch, that's the purpose of my question, is there a way to close an open sketch once we find there some open end on something already drawn? But I think I finally got it with the coincident constraint. See my reply to openBrain below.
openBrain wrote:
Wed Jan 23, 2019 6:22 pm
As I former stated, you need to use "coincident" constraint between the spline endpoints and the line endpoints to which they are attached. ;)
https://www.freecadweb.org/wiki/Sketche ... onstraints
I tried that but at first it was not working. Now I got it. I was trying to use the coincident constraint while I had angles constrain on the corner of my lines. So the coincident constraint was not working. I had to remove the angle contraints in order to do the coincident constraint! I will get there!
But now I'm still strugling with the fillet. I need to do a fillet on the front part of the lever (green line on the picture) and I have not succeeded yet. Or maybe there's another way than fillet to do it?
Better you provide the FCstd file and tell us what fillet radius you would use. So we can figure out what's going wrong. :)
Right now the radius is not very important, I just want to be able to do it on the edges I mention earlier. See the attached FCstd and my previous picture a few lines above.
Stou wrote:
Tue Jan 22, 2019 10:44 pm
Ok, thanks for the constrain info. I'm starting to be more comfortable with the constrain. It look like a mess but it is full contrain.
According the screenshots, I think your constraint usage still can be improved ;) :D Despite GeneFC would probably love it as it is :lol: :lol:
Yes a little bit ;-)
Attachments
ClutchLeverTLR.FCStd
(80.91 KiB) Downloaded 3 times