Sketches appear in different plane when project reloaded

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Andy_1205
Posts: 10
Joined: Mon Aug 12, 2019 8:31 pm

Sketches appear in different plane when project reloaded

Postby Andy_1205 » Sun Aug 18, 2019 8:59 am

Hi

I am wondering if I have done something wrong, or if there is a bug in Freecad 0.18?

I have been creating a model and have added features by clicking on a surface, then drawing a sketch and then padding etc to get the desired result. I added a datum line to add a circular pattern which worked well and I printed the model which came out ok, but needing minor adjustments.

When I loaded the FCSTD file, the polar array had an exclamation mark by it. When I edited the sketch that it was based on the pattern appeared in a plane 90 degrees to the one it was drawn on and the datum line.

The jpg shows the edge of the circle they should be on and where the sketch actually is.
Wrong Plane.jpg
Wrong Plane.jpg (411.25 KiB) Viewed 283 times
Can anyone explain this or advise how to avoid / solve?

Many thanks

Andrew
chrisb
Posts: 17475
Joined: Tue Mar 17, 2015 9:14 am

Re: Sketches appear in different plane when project reloaded

Postby chrisb » Sun Aug 18, 2019 9:39 am

Without the file you leave us merely guessing:

- Mark the root of the tree for recomputing and recompute the whole document
- You have attached your sketch to a face and ran in the topological naming issue (search the forum for that).

Have a look at this page, especially the paragraph about creating stable models how to avoid such behaviour.
Andy_1205
Posts: 10
Joined: Mon Aug 12, 2019 8:31 pm

Re: Sketches appear in different plane when project reloaded

Postby Andy_1205 » Sun Aug 18, 2019 11:18 am

Chris

Many thanks - it does seem to be the issue you allude to as I had deleted earlier items in the list when this happened.

Any suggestions what you should do to avoid it when you have multiple items in a list?

Andrew
chrisb
Posts: 17475
Joined: Tue Mar 17, 2015 9:14 am

Re: Sketches appear in different plane when project reloaded

Postby chrisb » Sun Aug 18, 2019 12:09 pm

Andy_1205 wrote:
Sun Aug 18, 2019 11:18 am
Any suggestions what you should do to avoid it when you have multiple items in a list?
What kind of list are you talking about?
Andy_1205
Posts: 10
Joined: Mon Aug 12, 2019 8:31 pm

Re: Sketches appear in different plane when project reloaded

Postby Andy_1205 » Fri Aug 23, 2019 8:15 am

Hi Chris

I am probably using the wrong term. I was meaning the 'Tree View' where it shows the 'Labels and Attributes', then 'Application', then 'Body' and under that, the constituent components that make up the body.

I have created a model by adding the parts in a logical (to me) way under the main body. As it contained multiple similar parts, I started to rename the components (pads, Fillets, Polars etc) to make them more understandable.

I then started to make changes after printing early prototypes and deleted some of the items from the middle of the list (or at least not the end). I then found that when I saved and re-opened the model, the polar patterns after the deleted item had lost the plane that they were attached to, and so their sketches were 'floating' in mid air on the original plane of the object.

One suggestion to resolve this was to 'recalculate' the entire model. I right clicked on the 'Body' and selected 'Mark to recompute' and a green tick appeared, but the errors were not corrected.

The only solution I have found is to delete everything beneath the original deleted object and add them again. I am hopeful this is not the correct solution otherwise it makes FreeCad much less useful a tool.

As with my other post you kindly helped with, I know I need to read the surrounding information on this bug, but have not had time to do so yet.

I think I need to go back to basics to understand the way that FreeCad builds these objects and 'best practice' when creating a model but need to find a resource to help with this and the time to use it.

With best wishes,

Andrew
chrisb
Posts: 17475
Joined: Tue Mar 17, 2015 9:14 am

Re: Sketches appear in different plane when project reloaded

Postby chrisb » Fri Aug 23, 2019 11:42 am

You don't have to recreate everything. The best way is to follow the hints for createing stable models mentioned above. But even without that you often can reattach the sketches to the appropriate faces. if that doesn't work you can almost always go over all subsequent features and reuse at least the sketches. A pocket or pad is quickly done compared to creating a sketch.
Andy_1205
Posts: 10
Joined: Mon Aug 12, 2019 8:31 pm

Re: Sketches appear in different plane when project reloaded

Postby Andy_1205 » Sat Aug 24, 2019 10:00 am

Chris

Can you point me in the direction or tell me how to reattach a sketch to a face? I have done a quick search but drawn a blank.

Andrew
chrisb
Posts: 17475
Joined: Tue Mar 17, 2015 9:14 am

Re: Sketches appear in different plane when project reloaded

Postby chrisb » Sat Aug 24, 2019 12:58 pm

https://www.freecadweb.org/wiki/Sketcher_MapSketch
Or: click on AttachmentOffset, click on the button appearing to the right and select the appropriate Attachment similar to https://www.freecadweb.org/wiki/Part_At ... hment_mode.
Andy_1205
Posts: 10
Joined: Mon Aug 12, 2019 8:31 pm

Re: Sketches appear in different plane when project reloaded

Postby Andy_1205 » Sat Aug 24, 2019 4:10 pm

Thank you - I will give that a go.

Andrew
chrisb
Posts: 17475
Joined: Tue Mar 17, 2015 9:14 am

Re: Sketches appear in different plane when project reloaded

Postby chrisb » Sat Aug 24, 2019 4:14 pm

You're welcome. You can always upload a model (up to 1MB size) and ask for help, if you get stuck.