Merge sketches and other questions

Post here for help on using FreeCAD's graphical user interface (GUI).
Forum rules
and Helpful information
IMPORTANT: Please click here and read this first, before asking for help

Also, be nice to others! Read the FreeCAD code of conduct!
GeneFC
Posts: 1358
Joined: Sat Mar 19, 2016 3:36 pm
Location: Punta Gorda, FL

Re: Merge sketches and other questions

Postby GeneFC » Wed May 27, 2020 1:54 am

Troymx576 wrote:
Tue May 26, 2020 9:28 pm
TheMarkster wrote:
Tue May 26, 2020 7:56 pm
The sketch has an error, hence the unsolved message. Always try to pay attention to the solver messages so when there's an issue you can resolve it before continuing. In the constraints list delete the last constraint (a vertical constraint).
Thank you. I see the error message now, but I do not know how to know what it is for. Is there a way to click or know how what is causing it?
Here is an example of a constraint conflict. The two nearly parallel dimensions are not physically possible, but for some reason the solver does not flag it. Even though the problem is not flagged it prevents a solution. If I delete one dimension the error goes away.

There are multiple examples of similar conflicts in your sketch. It does not seem there is an easy way to find the problems in this case; you just need to look carefully.

Conflict.png
Conflict.png (5.94 KiB) Viewed 182 times

Gene
chrisb
Posts: 25714
Joined: Tue Mar 17, 2015 9:14 am

Re: Merge sketches and other questions

Postby chrisb » Wed May 27, 2020 6:38 am

If an error is shown, you can click on the blue part of the message to see which constraints are involved, but often that shows much more than desired. I would second TheMarkster's recommendation: Always have a look at the solver message, check it after each constraint added. Be happy when the number of degrees of freedom goes down, and react immediately if an error is shown.
chrisb
Posts: 25714
Joined: Tue Mar 17, 2015 9:14 am

Re: Merge sketches and other questions

Postby chrisb » Wed May 27, 2020 6:40 am

GeneFC wrote:
Wed May 27, 2020 1:54 am
Here is an example of a constraint conflict.
That is serious. I will try to create a minimal example and then we should invoke Abdullah.
chrisb
Posts: 25714
Joined: Tue Mar 17, 2015 9:14 am

Re: Merge sketches and other questions

Postby chrisb » Wed May 27, 2020 8:05 am

GeneFC wrote:
Wed May 27, 2020 1:54 am
Even though the problem is not flagged it prevents a solution.
I guess I misunderstood your post. I interpreted it as if the sketcher does not recognize this situation, which I rated as being serious.

In fact the solver reports this sketch as being "unsolved", which is correct with the contradicting constraints. Sometimes it is misleading that the solver keeps the number of degrees of freedom as it was before.
I have the reduced file, just in case somebody is interested.
GeneFC
Posts: 1358
Joined: Sat Mar 19, 2016 3:36 pm
Location: Punta Gorda, FL

Re: Merge sketches and other questions

Postby GeneFC » Wed May 27, 2020 2:21 pm

I usually see this when there are conflicting constraints, in addition to error message at the top of the sketcher task panel.

Capture.PNG
Capture.PNG (8.25 KiB) Viewed 135 times

Gene
chrisb
Posts: 25714
Joined: Tue Mar 17, 2015 9:14 am

Re: Merge sketches and other questions

Postby chrisb » Wed May 27, 2020 6:33 pm

GeneFC wrote:
Wed May 27, 2020 2:21 pm
I usually see this when there are conflicting constraints, in addition to error message at the top of the sketcher task panel.
This message comes only when you try to add a dimension, which would lead to a conflict. It doesn't occur when adding a geometric constraint with a similar effect.
GeneFC
Posts: 1358
Joined: Sat Mar 19, 2016 3:36 pm
Location: Punta Gorda, FL

Re: Merge sketches and other questions

Postby GeneFC » Wed May 27, 2020 6:51 pm

My screen capture above was related to dimensions. 8-)

Gene
Troymx576
Posts: 17
Joined: Fri May 01, 2020 10:34 am

Re: Merge sketches and other questions

Postby Troymx576 » Fri May 29, 2020 4:40 am

I have another noob question and thanks in advance for helping.

I have an object and I created a sketch on the face. I had some failure to validate face error and fixed that I think.

I went to the face, created a sketch and tried to overlay the original sketch with the create an edged linked to an external geometry, yet it did not seem to line up and did not show up all the points.

I did create a pocket though and wanted to make it centered of the object so it would leave both faces untouched as I will want to do more there later. I need to remove a hole through all of it.

How do I center the pocket?

I will want to add a chamfer on the inside edge also.

I tried to make two pockets and have the line up with the face and then use boolean to combine the faces, but that did not let me chamfer the inner when done so I think I added complexity that should no be needed or missed a step.

I hope all that makes sense. I have been trying different things to figure it out and my brain is a little jumbled after all this.
Thanks
Troy
Attachments
pedalpocket01.jpg
pedal pocket
pedalpocket01.jpg (21.25 KiB) Viewed 80 times
TR-pedal-TroyA003.FCStd
pedal fcstd
(265.46 KiB) Downloaded 4 times
TheMarkster
Posts: 1728
Joined: Thu Apr 05, 2018 1:53 am

Re: Merge sketches and other questions

Postby TheMarkster » Fri May 29, 2020 5:54 am

If I understand what you are trying to do you just need to modify the z attachment offset of Sketch006 to something like z = -3mm.
Snip macro screenshot-359055.png
Snip macro screenshot-359055.png (137.23 KiB) Viewed 70 times
Note: it is not recommended to attach sketches to faces due to some issues it can cause if you decide later to modify some of the earlier sketches. If things go crazy you just need to go back in and reattach the sketches to the correct faces (usually anyway).
My FreeCAD video series on youtube: https://www.youtube.com/c/mwganson
chrisb
Posts: 25714
Joined: Tue Mar 17, 2015 9:14 am

Re: Merge sketches and other questions

Postby chrisb » Fri May 29, 2020 5:56 am

It's not completely clear to me what you want to achieve. Naming which sketches you are talking about may help as well as adding an image e.g. with some arrows added to show what you are talking about.

In the Sketch006 you have used already external references to circles. This includes the centers. If you want to center another circle with the references one, use a coincidence constraint on the centers.