External geometry tool problem with tutorial

[m3atwad]

Hello,

I'm new to freeCad and have been going through various tutorials to try to learn how to design some things. I was working through this particular tutorial:

http://www.freecadweb.org/wiki/index.ph ... n_Tutorial

and am stuck on the below section.\

Select New sketch from the toolbar or Part Design menu. Now in sketch edit mode, we will orbit back around to the front so we can see two perpendicular edges of the Pad we made in the last operation. Using the External geometry tool, select the connected horizontal and vertical edges at the base of the Pad with the External geometry tool. The image below shows the base edges to be selected with the External geometry tool.

(easy to find if you ctrl+f a section of the above text.

From what I have read searching google and these forums, you can only use the "create edge linked to external geometry tool" for lines or points on the same face as your sketch. It looks like in this tutorial (in the above mentioned section) the user is using this tool on a face that is NOT the same face as his sketch. Am I missing something here? I've been trying to figure this out and am having no luck getting past this part.

I'm using freeCad 0.16, windows 7 64 bit.

Thanks for the help!

[quick61]

Welcome to FreeCAD and the forum.

Selecting the external geometry on the reverse face will project that geometry onto the face your working on. While the external geometry will be only on the working face, it can come from most any edge and any vertex in the current features of the part. I say "most" any edge because edges that become BSplines during the modeling process are not supported in Sketcher. If you follow along with the tutorial, it does work and things are supposed to work that way.

Mark

[m3atwad]

Hey thanks for the reply quick61! I'm an EE and this is pretty new to me so bear with me lol. I think I get the idea of selecting it and using it on a different face, but the external geometry tool button doesn't let me select anything on that face. Is there something you have to do to be able to use the external geometry tool on a different face than the sketch? I get the cursor, but when I click it just gives me the error symbol and the error sound.

Thanks again for your time!

[quick61]

Hey thanks for the reply quick61! I'm an EE and this is pretty new to me so bear with me lol. I think I get the idea of selecting it and using it on a different face, but the external geometry tool button doesn't let me select anything on that face. Is there something you have to do to be able to use the external geometry tool on a different face than the sketch? I get the cursor, but when I click it just gives me the error symbol and the error sound.

Thanks again for your time!

If your not able to select that external geometry, it is most likely you have forked the model.If you could post the file with your part, I should be able to tell you where the error is and how to fix it.

Mark

[m3atwad]

Hey Mark,

Unfortunately I deleted it What does forked mean?

I'll try to run through the tutorial again this tomorrow and upload what I have. Should I upload the project file?

Thanks,
Rob

[bejant]

What does forked mean?

http://www.freecadweb.org/wiki/index.ph ... rked_Model

Should I upload the project file?

Yes, please.

[wadesmart]

I downloaded FC a few days ago and have been going through the same tutorials. In the same location - I cant figure it out either. After reading what "forked" is, Im not sure that is the problem. Ive started over several times and while the wording may be clear, what you are actually doing is not.

"Now orbiting around to the back face, or alternatively double clicking on the active sketch in the Model tree view, you will see the two external geometry lines that we provided from the front of the model. Make a rectangle and using the coincident constraint, do the following.

Select the upper left vertex of the rectangle and the upper left point of the external geometry and click on the coincident constraint.
Click on the lower right vertex of the rectangle and the lower right point of the external geometry and click on the coincident constraint."

Just above this section of text is a image showing where to click on the right to see the "L" shaped constraint on the left. That part is clear and doable. The next part is the trouble area. As I read bejant post - sounds like Im not alone. Once the two lines are there the instructions say to make a box by doing the following (posted above) but, as far as I can tell, that doesnt work. Dumbing this down, '..select the upper left circle of the rectangle and the upper left point of the external geometry and click on coincident constraint.' Im not sure where the "point" is they want me to click but after having clicked on everything that I think they may be talking about - nothing gets me to where I can click on coincident constraint as its grayed out.

https://goo.gl/photos/3M2UN8L34NGK9SGD6

The image shows what I and, Im guessing bejant, were able to see but were not able to do. I can click on the upper left circle and the line to the right of it, or the top or bottom right circle and or the lines but nothing else is clickable.

[bejant]

In the same location - I cant figure it out either.

Hi wadesmart, and welcome to FreeCAD. Here's a video I just made of that portion of the tutorial:
https://youtu.be/dlQV9OkXWOI

OT note to Mark and everyone else: I've gone through the tutorial and recorded it step by step and can post it to my YouTube, or if a moderator would like to somehow include them in the wiki tutorial I can give you a link to the videos if you like after I go through them and edit out any mistakes I may have made. I'm mentioning it here so someone else doesn't do it again if they don't want to make another video of the tutorial now that it's been done.

I remember reading a topic about including videos in the tutorials and like the idea, but I'd like like to know how we should do that. Also, I don't care whether or not the ones I've just done (or any of the others I've done) are on my YouTube page or some official FreeCAD YouTube page.

[wadesmart]

I worked on this until pretty late last night and I finally got it too

Good going on the video. Smart move.

[bejant]

I uploaded videos of the other portions of the tutorial to YouTube too, and updated the wiki by including links to them.

Also, here's the model:

BasicPartDesignTutorial.fcstd

(71.66 KiB) Downloaded 76 times

OS: Ubuntu 14.04.4 LTS
Word size of OS: 32-bit
Word size of FreeCAD: 32-bit
Version: 0.16.6703 (Git)
Build type: None
Branch: releases/FreeCAD-0-16
Hash: 2ce5c8d2e3020d05005ed71f710e09e9aa561f40
Python version: 2.7.6
Qt version: 4.8.6
Coin version: 4.0.0a
OCC version: 6.8.0.oce-0.17


OT: the numerals and text in the image appear huge on my screen. This is a direct link to the image:


And this is a screen grab of how it appears on my screen:

20160705a.png (117.54 KiB) Viewed 4350 times

Does anyone else have this display issue, or is it just me?