Invalid constraint index: 24

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ProApe
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Joined: Mon Sep 12, 2022 3:13 pm

Invalid constraint index: 24

Post by ProApe »

Hi,

Why do I get this error message when applying an angle of 135° between both lines?
The error messages I get are very cryptic for me. Where can I get explanations for them?

Kind regards
ProApe
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NewJoker
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Re: Invalid constraint index: 24

Post by NewJoker »

This needs to be fixed:

problem.png
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Then trim the lines separating those ears from the slot and constrain the sketch properly.
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Shalmeneser
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Re: Invalid constraint index: 24

Post by Shalmeneser »

Small line cause problem.
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Shalmeneser
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Re: Invalid constraint index: 24

Post by Shalmeneser »

Beware that bad sketch cannot be padded :
* no T-junction
* clear border with clear inside / outside

Do not try to do everything inside the same sketch : KISS method.

Btw, do not sketch upon face : TNP
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ProApe
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Re: Invalid constraint index: 24

Post by ProApe »

Hello,

thank you very much for the quick answers!

@"Shalmeneser": this drawing is indeed from a tutorial, where the drawing is not done on existing surfaces, but always on a new sketch that is placed on the XY-plane. I didn't stick to it now, after I successfully did a tutorial yesterday where drawing was done on existing surfaces, and was of the opinion that in version 0.20 this problem was fixed. Is this not the case?

@"NewJoker": this line that you write has to be fixed, but has nothing to do with the fact that I cannot change the angle?

Sincerely
ProApe
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Shalmeneser
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Re: Invalid constraint index: 24

Post by Shalmeneser »

TNP is not fixed atm in 0.21 (and even if it will be fixed, do not sketch upon face).
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NewJoker
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Re: Invalid constraint index: 24

Post by NewJoker »

ProApe wrote: Wed Dec 07, 2022 10:21 am this line that you write has to be fixed, but has nothing to do with the fact that I cannot change the angle?
Sketches should have such invalid lines fixed before applying constraints to ensure their proper functioning.
Shalmeneser wrote: Wed Dec 07, 2022 10:30 am even if it will be fixed, do not sketch upon face
It seems to be a bit of an exaggeration. Sketching on faces is normal in other CAD software and with TNP almost non-present it shouldn't be so risky to use it. Even now I keep sketching on faces and never encounter TNP. Maybe because I don't make significant modifications to my models and draw rather simple stuff but with a bit of care one can easily avoid issues that can be caused by sketching on faces. Alternative workflows are just too tedious to use on a daily basis.
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Shalmeneser
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Re: Invalid constraint index: 24

Post by Shalmeneser »

If you want to change the order of some features, you need to works with independent features.
Lonfor
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Re: Invalid constraint index: 24

Post by Lonfor »

NewJoker wrote: Wed Dec 07, 2022 10:59 am It seems to be a bit of an exaggeration.
It is not if you expend a whole night modeling and then, suddenly, the model explodes in such a way that it is impossible to repair.
So, in FreeCAD the hardcore approach at modelling is a must if you want a stable model.
Right now, I have a casting model that until now I remade at least a dozen times because of TNP and invalid solid and invalid wires (Open Cascade kernel issues I guess), it is not finished yet but I am seriously considering to make the fillets one by one by sweeping sketches and perhaps resorting to surface modeling, face by face to get those fillets right. :x

As an example please take a look at the dependency graphic, there are a lot of operations, and not even one references a face or edge. Granted, it is too much trouble, but it is the price to pay for a stable model.
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papyblaise
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Re: Invalid constraint index: 24

Post by papyblaise »

parles m'en sur mon chat :!:
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