## How do I find the 16 needed constraints

Post here for help on using FreeCAD's graphical user interface (GUI).
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keithsloan52
Posts: 1091
Joined: Mon Feb 27, 2012 5:31 pm

### How do I find the 16 needed constraints

See attached file
Hide_Door2.FCStd
drmacro
Posts: 306
Joined: Sun Mar 02, 2014 4:35 pm

### Re: How do I find the 16 needed constraints

The number/word "16 degrees" is clickable.

When you click on it, the objects that are not constrained are highlighted in green.
openBrain
Posts: 3089
Joined: Fri Nov 09, 2018 5:38 pm

### Re: How do I find the 16 needed constraints

First, there are a lot of 16-constraint sets that work. Also there a lot (much more) that don't work.
Then FC by itself will not make it magically happen for you. This is human cleverness to find which set is correct and fits what you want.
You need to learn and practice to gain skill/knowledge/know-how.
However having good geometry knowledge ease things. Reading chrisb's tutorial is also a good entry point to understand DoF concept (as applied in solver of sketcher).
bejant
Posts: 6059
Joined: Thu Jul 11, 2013 3:06 pm

### Re: How do I find the 16 needed constraints

The endpoints of the upper 2 inner rectangles are missing some Coincident Constraints:
20200114a.png (2.6 KiB) Viewed 249 times
keithsloan52
Posts: 1091
Joined: Mon Feb 27, 2012 5:31 pm

### Re: How do I find the 16 needed constraints

Okay I got down to seven, but now seem to be stuck
Hide_Door2.FCStd
drmacro
Posts: 306
Joined: Sun Mar 02, 2014 4:35 pm

### Re: How do I find the 16 needed constraints

The reason you are stuck is many of the end points of your geometry were not coincident and thus were not constrained as yet.

I would recommend you use the rectangle tool to draw rectangles, it will produce rectangles with coincident corners.

I have attached my take on what you are attempting, just for reference.
Attachments
Hide_Door2-mac.FCStd
openBrain
Posts: 3089
Joined: Fri Nov 09, 2018 5:38 pm

### Re: How do I find the 16 needed constraints

You can use the Sketcher ValidateSketch tool to find open vertices and missing coincidences.
keithsloan52
Posts: 1091
Joined: Mon Feb 27, 2012 5:31 pm

### Re: How do I find the 16 needed constraints

Thanks
keithsloan52
Posts: 1091
Joined: Mon Feb 27, 2012 5:31 pm

### Re: How do I find the 16 needed constraints

Okay I am now trying to make two circular holes in sketch001.
Hide_Door2-A.FCStd
They seem to display as construction lines and I try toggle them.
Or do I need to drill them separately?

Thanks
drmacro
Posts: 306
Joined: Sun Mar 02, 2014 4:35 pm

### Re: How do I find the 16 needed constraints

When the lines of a sketch are blue, that means they are construction geometry. Choose
Toggel_construction.png (950 Bytes) Viewed 103 times
to toggle from/to construction mode.
door_w_holes.png (3.34 KiB) Viewed 103 times
Attachments
Hide_Door2-A-mac.FCStd