Sketch seems to be lost

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falviani
Posts: 150
Joined: Tue May 07, 2019 8:49 pm

Sketch seems to be lost

Postby falviani » Thu May 09, 2019 2:43 pm

Hello,

This is my first post, asking for help of course. I am starting to learn FreeCad to use in designing items to 3D print. The rules suggest I include the data from the about box, so here it is:

OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.16110 (Git)
Build type: Release
Branch: (HEAD detached at upstream/releases/FreeCAD-0-18)
Hash: f7dccfaa909e5b9da26bf50c4a22ccca9bb10c40
Python version: 3.6.6
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedStates (en_US)

Summary: I designed a part to print successfully and save it. When I went back to make a minor adjustment to the initial sketch, nothing displayed when I brought up the sketch editor. I can see why it's not editable, but have no idea how the file ended up in the current state. I tried to collect all the useful information to track down what I did wrong (see below).
Data to track down what I did wrong.
Data to track down what I did wrong.
Combined.png (75.15 KiB) Viewed 829 times
The process I followed was approximately:
1) Part design: Create body, then sketch. Use polyline tool to create the main outline ('A' in the pad diagram). Once fully constrained, used the pad operation to extrude it to 10 mm.
2) Part: Create a cube ('B'), adjust position, dimensions and angle, and add it to the pad from (1).
3) Part: Create a cube ('C'), adjust position and dimensions, and add it to (2).
4) Save file and export to STL.

Why did the hierarchy end up as it did? I am just learning FreeCad, and the tutorials I've seen so far don't address anything of this nature.

My questions are:
1) How can I avoid this in the future?
2) Is it possible to 'fix' the file so the intial sketch is editable again?

Thanks in advance for all your help. I had been trying to use Blender, which I am moderately familiar with, but decided I need to use a real CAD tool to do 3D design work. FreeCAD is looking very promising once I get past the learning curve.

Frank Alviani
Attachments
LightBarHolder_v2.FCStd
File with problems
(38.32 KiB) Downloaded 12 times
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HarryGeier
Posts: 1230
Joined: Mon Jul 10, 2017 12:36 pm
Location: Hof Germany

Re: Sketch seems to be lost

Postby HarryGeier » Thu May 09, 2019 3:34 pm

faviano,


Just select the sketch and use spacebar to make it visible

fusion001 also needs to be switched visible..


your questions:
When you do boolean operations, the source elements get invisible
Your whole tree is somewhat weird.You can do all of that in one singe step or few sketches and pads. No needs for any coube´s or fusions at all.

But don´t mind, usual beginners problems.

Enjoy a few of my videos and then all will be good , you will then know how to get on the right track.

harry
Last edited by HarryGeier on Thu May 09, 2019 3:40 pm, edited 1 time in total.
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meme2704
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Re: Sketch seems to be lost

Postby meme2704 » Thu May 09, 2019 3:39 pm

Hi
You made a mixture of Part and Partdesign, suddenly the body that contains Sketch is invisible (gray) click on, and bar expatiates 2time and it becomes visible again
finally, remove the visble lines of the fused Cube by doing "Refine = True
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quick61
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Location: u.S.A.

Re: Sketch seems to be lost

Postby quick61 » Thu May 09, 2019 3:42 pm

Looking at your file, Your first sketch is editable, once you unhide it. Even when one opens it up for editing, you can't see it because the entire body that it is contained in remains hidden. Unhide LightBarHolder and then attempt to edit the sketch and see what you get.

Until I or someone else looks closer at your file, I can't say for certain what you exactly did, but if your just starting out with FreeCAD, start out by first completing a part within one workbench. With a part this simple, there is no need to add Part primitives to your sketched and padded part and Fuse them. You could of / should of either edited the original sketch, or added additional sketches to the part. - - hint, Pad has a reverse option in the dialog. - -

Mark

Edit - It looks like your Fusion of the parts is all out of wack. See the red lines in the dependency graph? They shouldn't be there. To fix this, first delete Fusion and Fusion001. Then in Part workbench, select LightBarHolder (body) and Cube and Cube001, (all 3 parts) then do a single fusion. Once done, your dependency graph should look like this. -
depgph.png
depgph.png (20 KiB) Viewed 801 times
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openBrain
Posts: 6099
Joined: Fri Nov 09, 2018 5:38 pm

Re: Sketch seems to be lost

Postby openBrain » Thu May 09, 2019 4:08 pm

Hi falviani, welcome here.

First notice that one of the bodies is in Display Mode = Tip which will prevent sketch editing. You have to turn is back to Through. ;)
Also in your Sketch, there is something like a null-length line as complained by FC in the report view. The element "16-Line" is the culprit and can be simply removed.

Beyond what was already said, indeed your model seems to be a bit 'messy'.

Fusion001 fuses Fusion with items that are already contains in Fusion itself, which not really has a sense.
Also each fusion has a double reference to the body. One is correct (to the body itself) but the other is not (to the pad that is inside the body).

All in all your file can be simplified to the one attached.
LBH_OB.png
LBH_OB.png (40.36 KiB) Viewed 800 times
Attachments
LightBarHolder_OB.FCStd
(22.02 KiB) Downloaded 8 times
falviani
Posts: 150
Joined: Tue May 07, 2019 8:49 pm

Re: Sketch seems to be lost

Postby falviani » Fri May 10, 2019 2:30 am

Thanks to all for the advice - it is valuable. After this was posted, I stumbled across the visibility issue and was able to edit the appropriate sketch. I will take the suggestions to heart as I do further designs. :)