Problems with Pad when constructing girder bridge deck

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chrisb
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Re: Problems with Pad when constructing girder bridge deck

Post by chrisb »

Padding such an unconnected sketch violates the single solid rule.
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PeterSD
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Re: Problems with Pad when constructing girder bridge deck

Post by PeterSD »

chrisb wrote: Thu Jan 06, 2022 3:43 pm Padding such an unconnected sketch violates the single solid rule.
Thanks for the reminder Chris. I remember now that FreeCAD does not accept such a situation I only did this to see if it had an effect that could help to narrow down the reason for this PAD anomaly. Having already found that, connecting the sketch you can see raised and with the missing connection line in , I still found the tapered chamfered feature.
Deck Rev 4_a Reduced width.FCStd
(68.63 KiB) Downloaded 8 times
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Shalmeneser
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Re: Problems with Pad when constructing girder bridge deck

Post by Shalmeneser »

TNP ?
no file no gain.
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Re: Problems with Pad when constructing girder bridge deck

Post by PeterSD »

Shalmeneser wrote: Thu Jan 06, 2022 6:03 pm TNP ?
no file no gain.
Thanks for your reply. I hope not :!:
To complete this exercise, I have reconnected sketch 003 but the result on padding remains the same. Also note the number of lines in the sketch are exactly what is expected and connected to Element 10 which is on the top surface of the Bridge Deck (Sketch000).
Sketch 003 reconnected Again.PNG
Sketch 003 reconnected Again.PNG (268.52 KiB) Viewed 1023 times
To remind you of the Pad in this condition.
Pad following reconnection of Sketch 003..PNG
Pad following reconnection of Sketch 003..PNG (89.18 KiB) Viewed 1023 times
I have expanded the Pad Properties in case any clues lie within this.
Also note that sketch 003 is showing an error now.
I have run out of things to try and would welcome any suggestions.

UPDATE A final view of the sketch attached to body might also help.
3D view of PAD Surface and sketch.PNG
3D view of PAD Surface and sketch.PNG (77.16 KiB) Viewed 998 times
Last edited by PeterSD on Thu Jan 06, 2022 10:25 pm, edited 1 time in total.
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Shalmeneser
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Re: Problems with Pad when constructing girder bridge deck

Post by Shalmeneser »

no file no gain.
PeterSD
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Re: Problems with Pad when constructing girder bridge deck

Post by PeterSD »

Shalmeneser wrote: Thu Jan 06, 2022 10:16 pm no file no gain.
Thanks, I now understand. I did post the file above but hear goes again.
Deck Rev 4_a Reduced width.FCStd
(67.23 KiB) Downloaded 12 times
Hope this helps.
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bambuko
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Re: Problems with Pad when constructing girder bridge deck

Post by bambuko »

PeterSD wrote: Thu Jan 06, 2022 10:40 pm ....I did post the file above but hear goes again...
above and below is a "fluid" concept on internet forums, depending on your settings (for me it is actually below :mrgreen: )
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PeterSD
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Re: Problems with Pad when constructing girder bridge deck

Post by PeterSD »

bambuko wrote: Thu Jan 06, 2022 11:03 pm
PeterSD wrote: Thu Jan 06, 2022 10:40 pm ....I did post the file above but hear goes again...
above and below is a "fluid" concept on internet forums, depending on your settings (for me it is actually below :mrgreen: )
Great! :D Just in time to remind me the world is 3 Dimensions. Good to have a laugh at a time like this.
chrisb
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Re: Problems with Pad when constructing girder bridge deck

Post by chrisb »

Perhaps this helps:
Whenever you cross a line, you switch from outside to inside or vice versa. If this is not possible, then a sketch cannot be padded.

Example:
Let's assume this sketch, you come from the left border and walk to the right
SnipScreenshot-1049fc.png
SnipScreenshot-1049fc.png (8.38 KiB) Viewed 917 times
- You start at the outside
- you pass the first vertical line, no you are inside; this will be solid
- you pass the circle, now you are outside, this will be a hole with no material
- you pass the other side of the circle, you are inside again
- you pass the left vertical line of the inner rectangle and are outside again
- pass the right vertical line of the inner rectangle and are inside again
- pass the rightmost vertical line and you are outside again

This is what the pad will look like:
SnipScreenshot-a22bb3.png
SnipScreenshot-a22bb3.png (5.77 KiB) Viewed 917 times
Now consider your sketch, look at the left lower line: Which side is inside, and which is outside?
SnipScreenshot-657f87.png
SnipScreenshot-657f87.png (1.66 KiB) Viewed 917 times
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PeterSD
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Re: Problems with Pad when constructing girder bridge deck

Post by PeterSD »

chrisb wrote: Fri Jan 07, 2022 12:22 am Perhaps this helps:
Whenever you cross a line, you switch from outside to inside or vice versa. If this is not possible, then a sketch cannot be padded.

Example:
Let's assume this sketch, you come from the left border and walk to the right
SnipScreenshot-1049fc.png

- You start at the outside
- you pass the first vertical line, no you are inside; this will be solid
- you pass the circle, now you are outside, this will be a hole with no material
- you pass the other side of the circle, you are inside again
- you pass the left vertical line of the inner rectangle and are outside again
- pass the right vertical line of the inner rectangle and are inside again
- pass the rightmost vertical line and you are outside again

This is what the pad will look like:
SnipScreenshot-a22bb3.png
Now consider your sketch, look at the left lower line: Which side is inside, and which is outside?
SnipScreenshot-657f87.png
Thanks very much Chris for your explanation :D .
I have run through this several times but need to think about it further to make sure my tired brain fully understands. At first glance it seems an impossible quandary yet I know I have successfully constructed this structure several times already. I shall look for the different approach (es) I have taken in the past and check the differences. I shall look at this again in the morning and let you know what I have made of all this.
Many thanks again. It is far better to know I have a potential way forward to resolve this than being stuck at a dead end.
Kind Regards
Peter
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