Datum Plane orientation request

[Zolko]

Could you give some preferably simple or very simple examples which show the power of LCSs?

in the attached demo, select Local_CS001, and then change AttachmentOffsets (Z and Roll for example) in the Property window and see what happens. Of course you could do that otherwise too. If your changes are too wild the fillet might not pass.

LCS_demo.png (283.84 KiB) Viewed 584 times

[ppemawm]

in the attached demo, select Local_CS001, and then change AttachmentOffsets (Z and Roll for example) in the Property window

Thank you for the example. I am trying to understand the advantages of the LCS compared to the Body origin and sketch attachment properties.
When I try to make any attachment change to the Local_CS001 the model breaks as shown below. What version are you using?

Picture1.jpg (42.07 KiB) Viewed 516 times

OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15697 (Git)
Build type: Release
Branch: master
Hash: dedaa807629ab25cf32977d30bf7610f1346aff7
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedStates (en_US)

[Zolko]

Thank you for the example. I am trying to understand the advantages of the LCS compared to the Body origin and sketch attachment properties.

As I understand, you can have only 1 Origin in a Part or Body, but you can have many LCS

When I try to make any attachment change to the Local_CS001 the model breaks as shown below. What version are you using?

OS: Ubuntu 18.04.1 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15363 (Git) AppImage
Build type: Release
Branch: master
Hash: 9be3e633328335f1172456f5857219b7a08c70a5
Python version: 3.6.7
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedKingdom (en_GB)


as it looks, you're editing the "MapMode", try with the "AttachmentOffset" (2 lines below)

[ppemawm]

As I understand, you can have only 1 Origin in a Part or Body, but you can have many LCS

But, you can have any number of sketch attachment offsets.

try with the "AttachmentOffset" (2 lines below)

Same, same result.

[Zolko]

As I understand, you can have only 1 Origin in a Part or Body, but you can have many LCS

But, you can have any number of sketch attachment offsets.

yes, I know that you can do the same with other tools. But how do you visualize the position of the sketch when you're creating it ? Also, what if you want to attach more stuff on the same position ? Like a sketch, a Datum Line ...

try with the "AttachmentOffset" (2 lines below)

Same, same result.

strange .... dunno

LCS_demo2.png (352.54 KiB) Viewed 505 times

[ppemawm]

I do like the visual aid of an LCS. I'll have to give it a go in my next assembly model.

strange .... dunno

I suppose one of us should submit a bug report if someone can duplicate the behavior
with the latest development version 0.18.15697.

[Syres]

First thing to say, I had to remake the Fillet in @Zolko's demo file for any of my builds to work including the latest ASM3. Then with my modified file (attached) I narrowed the issue down to a Py3Qt5 problem based on just changing the Roll anywhere between 90 and 45 degrees in the same build revision:

Works using:

OS: Windows 7
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15697 (Git)
Build type: Release
Branch: master
Hash: dedaa807629ab25cf32977d30bf7610f1346aff7
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedKingdom (en_GB)


Doesn't work using:

OS: Windows 7
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15697 (Git)
Build type: Release
Branch: master
Hash: dedaa807629ab25cf32977d30bf7610f1346aff7
Python version: 3.6.6
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedKingdom (en_GB)

The oldest Py3Qt5 build I have is 018.15468 and it fails in that too.

[ppemawm]

Thanks for looking into this.

I had to remake the Fillet in @Zolko's demo file...Then with my modified file...

Your modified file now works as expected with my version, so perhaps it is not a bug but a problem with the original model?
I am able to make indiscriminate changes in the offsets and angles of the Local_CS001 without the model breaking.

OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.15697 (Git)
Build type: Release
Branch: master
Hash: dedaa807629ab25cf32977d30bf7610f1346aff7
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedStates (en_US)

[Zolko]

Looks like an OCC bug: I tested my demo file and yours, and mine always works on OCC 7.3, and never on anything else, and yours always works on anything except 7.3

First thing to say, I had to remake the Fillet in @Zolko's demo file for any of my builds to work including the latest ASM3. Then with my modified file (attached) I narrowed the issue down to a Py3Qt5 problem based on just changing the Roll anywhere between 90 and 45 degrees in the same build revision:

Works using:

Version: 0.18.15697 (Git)
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0

Doesn't work using:

Version: 0.18.15697 (Git)
Python version: 3.6.6
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0

The oldest Py3Qt5 build I have is 018.15468 and it fails in that too.

I have:

OS: Ubuntu 18.04.1 LTS
Version: 0.18.LinkStage3-z
Build type: Unknown
Python version: 3.6.7
Qt version: 5.9.5
Coin version: 4.0.0a
OCC version: 6.9.1.oce-0.18

and:

OS: Ubuntu 18.04.1 LTS
Version: 0.17.13541 (Git) AppImage
Build type: None
Branch: releases/FreeCAD-0-17
Hash: 9948ee4f1570df9216862a79705afb367b2c6ffb
Python version: 2.7.6
Qt version: 4.8.6
Coin version: 4.0.0a
OCC version: 7.3.0

I've actually been hit by this bug before, but I thought it was my fault:

You are using an older OCCT 6.9. It is (so much) better to use 7.3 (used in my AppImage) instead. That's probably why you are getting lots of model breaking when switching between different FC builds. And that may also be part of the reason of the above performance difference.

[Syres]

Looks like an OCC bug: I tested my demo file and yours, and mine always works on OCC 7.3, and never on anything else, and yours always works on anything except 7.3

Ok, thank you for the explanation, I don't use PD much and my models are nothing like as comprehensive as @ppemawm produces so I've never come across any OCC bug as much as I swap between OCC 7.2 and 7.3.