OK, I'm Stuck... Complete Newbie

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freedman
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Re: OK, I'm Stuck... Complete Newbie

Post by freedman »

- About 2:30 into the video, things continue to fall apart. He has the Task tab open, he clicks on the top left corner, the center line, the top right corner and then the "><". That forces the rectangle to center line on the center line. When I do the same thing, it displays "><" on the vertical line, but doesn't move anything.
Every once in a while when doing symmetry constraints I see a delay or a hang, I then wonder why I didn't see the lines move. I guess there is a random issue with this process, if I zoom out or kind of do anything the screen updates the constraint correctly. This has never been bad enough to raise an issue but I could see how it might be a bit confusing. Using 0.18.16, win10
chrisb
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Re: OK, I'm Stuck... Complete Newbie

Post by chrisb »

I think in the video it is somethng different. It was made when redundant constraints were not always reported. In the video the vertical line has already a vertical constraint and then an additional point-X-axis-point constraint is added. This was allowed in 0.17, and it usually worked for some features, and then the model failed in some later steps. You may search the archives, we had loads of questions arising from these.
The current sketcher detects them. While the solver shows his error message no visual update to the sketch is made.
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dave_w
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Re: OK, I'm Stuck... Complete Newbie

Post by dave_w »

chrisb wrote: Mon Mar 16, 2020 12:36 am
- About 2:30 into the video, things continue to fall apart.
The way he uses symmetry now creates a "redundant constraints" message. It was the reason why I created my sketcher tutorial, which is only available as pdf but not as video. The better way to center a rectangle is to select diagonal corners and then the center and create the symmetry.
Yes, I found the redundant constraints and deleted them. That let me get past this, but still stuck on very basic things.

Dave
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Re: OK, I'm Stuck... Complete Newbie

Post by dave_w »

MSOlsen65 wrote: Mon Mar 16, 2020 2:37 am Dave,

As a fellow newbie I can tell you that you are getting fantastic advice from some MAJOR players on the forum. :D That said, when using YouTube, take the time to check out the account posting the video. Often the author will have several related videos, some of which may include bits of info assumed in later ones.

As to the specific video by mathcodeprint (mcp) that you cited, while a good video overall, it is not targeted at a novice audience. From watching many of mcp's videos, I would rate most as being for advanced beginners or above. He goes very quickly through his demos, and presume a moderate degree of familiarity and comfort with both Part and Part Design workbenches.

For myself, I found that sliptonic is a very good YouTube author for FreeCAD videos. He has a set of 4 aimed at the true novice. Go to his chanel and review al his videos. You should be able to easily find ones for you level. They should have you comfortable with the Part Design workbench fairly quickly.

Finally, you have run into the same issue I had awhile back -- Part vs. Body. For now, understand that Part Design workbench does not make parts. It makes bodies. Which for most purposes, are what newbies would call parts. Yes there is a separate entity called Part (std_part is its coded name), but it is not what most users mean when speaking about making or drawing a part. The situation is, in my opinion, an extremely confusing and unfortunate naming quirk. :evil: That said, I have greatly oversimplified the situation, but it should be enough to get you started in reaching your goals.

Hope this helped. Like I said at the becoming, you already have some excellent people helping you. I'm just another newbie letting you lnow what I found helpful.
Absolutely! I'm appreciative of the help I'm getting even after I abused the privilege early on. Unfortunately, I still have not found a path that helps me learn. I did not find any basic example videos from sliptonic. I still cannot start with a tutorial video and get more than a few minutes in doing (what I believe is) the exact same steps the tutor is doing and getting the same results.

Dave
drmacro
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Re: OK, I'm Stuck... Complete Newbie

Post by drmacro »

dave_w wrote: Mon Mar 16, 2020 5:47 pm Absolutely! I'm appreciative of the help I'm getting even after I abused the privilege early on. Unfortunately, I still have not found a path that helps me learn. I did not find any basic example videos from sliptonic. I still cannot start with a tutorial video and get more than a few minutes in doing (what I believe is) the exact same steps the tutor is doing and getting the same results.

Dave
Maybe working along with videos is not "your" way of learning. Most, if not all, of the videos are made by people just trying to share, not professional teachers, many not even in their first language.

One thing I note about the video you first mentioned is, it's actually talking about things that aren't "first introductory" things. (IMO) External geometry reference is definitely useful, but, you need to grok some things and experience some "hmm...why doesn't that work...hmm...OH! that
's why" moments on more basic stuff.

The very basics are, in Part Design: create a Body, create a sketch, draw some lines (lines, arcs, etc.) that form the desired shape, make sure the ends of the lines are coincident (if they aren't it won't pad or pocket), close the sketch, pad. ( have to have at least one pad, before pockets.)

So without a video:

New document; Can you draw a rectangle and pad it?

New document; Can you draw a circle and pad it?

New document; Can you draw a rectangle, pad it, select the top face of the rectangle, create a new sketch, in the new sketch draw a circle, close the sketch, then pad it?

New document; Can you draw a rectangle, pad it, select the top face of the rectangle, create a new sketch, in the new sketch draw a circle, close the sketch, then pocket it?

I'm guessing the stuff that you can't get to be identical to the tutorials is beyond these things and are confusing you needlessly. (And, note, I'm not chastising here, I get it, I used to teach this CAD stuff for a living to Oooooold engineers (like ones who grew up using drafting boards and slide rules.) ;) )
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
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MSOlsen65
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Re: OK, I'm Stuck... Complete Newbie

Post by MSOlsen65 »

drmacro wrote: Mon Mar 16, 2020 6:16 pm
dave_w wrote: Mon Mar 16, 2020 5:47 pm Absolutely! I'm appreciative of the help I'm getting even after I abused the privilege early on. Unfortunately, I still have not found a path that helps me learn. I did not find any basic example videos from sliptonic. I still cannot start with a tutorial video and get more than a few minutes in doing (what I believe is) the exact same steps the tutor is doing and getting the same results.

Dave
Maybe working along with videos is not "your" way of learning. Most, if not all, of the videos are made by people just trying to share, not professional teachers, many not even in their first language.

One thing I note about the video you first mentioned is, it's actually talking about things that aren't "first introductory" things. (IMO) External geometry reference is definitely useful, but, you need to grok some things and experience some "hmm...why doesn't that work...hmm...OH! that
's why" moments on more basic stuff.

The very basics are, in Part Design: create a Body, create a sketch, draw some lines (lines, arcs, etc.) that form the desired shape, make sure the ends of the lines are coincident (if they aren't it won't pad or pocket), close the sketch, pad. ( have to have at least one pad, before pockets.)

So without a video:

New document; Can you draw a rectangle and pad it?

New document; Can you draw a circle and pad it?

New document; Can you draw a rectangle, pad it, select the top face of the rectangle, create a new sketch, in the new sketch draw a circle, close the sketch, then pad it?

New document; Can you draw a rectangle, pad it, select the top face of the rectangle, create a new sketch, in the new sketch draw a circle, close the sketch, then pocket it?

I'm guessing the stuff that you can't get to be identical to the tutorials is beyond these things and are confusing you needlessly. (And, note, I'm not chastising here, I get it, I used to teach this CAD stuff for a living to Oooooold engineers (like ones who grew up using drafting boards and slide rules.) ;) )
Way to go drmacro! Now that is solid home run advice. By the way, I am one of those Engineers who knows how to use a slide rule effectively. :oops: :mrgreen:
Sincerely,


Michael S. Olsen
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dave_w
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Re: OK, I'm Stuck... Complete Newbie

Post by dave_w »

drmacro wrote: Mon Mar 16, 2020 6:16 pm Maybe working along with videos is not "your" way of learning. Most, if not all, of the videos are made by people just trying to share, not professional teachers, many not even in their first language.
Obviously not. :D
drmacro wrote: Mon Mar 16, 2020 6:16 pm One thing I note about the video you first mentioned is, it's actually talking about things that aren't "first introductory" things. (IMO) External geometry reference is definitely useful, but, you need to grok some things and experience some "hmm...why doesn't that work...hmm...OH! that
's why" moments on more basic stuff.
Agreed. I see the usefulness of external geometry and would like to use it, but I've moved past that.
drmacro wrote: Mon Mar 16, 2020 6:16 pm The very basics are, in Part Design: create a Body, create a sketch, draw some lines (lines, arcs, etc.) that form the desired shape, make sure the ends of the lines are coincident (if they aren't it won't pad or pocket), close the sketch, pad. ( have to have at least one pad, before pockets.)

So without a video:

New document; Can you draw a rectangle and pad it?
Yes.
drmacro wrote: Mon Mar 16, 2020 6:16 pm New document; Can you draw a circle and pad it?
Yes.
drmacro wrote: Mon Mar 16, 2020 6:16 pm New document; Can you draw a rectangle, pad it, select the top face of the rectangle, create a new sketch, in the new sketch draw a circle, close the sketch, then pad it?
Yes.
drmacro wrote: Mon Mar 16, 2020 6:16 pm New document; Can you draw a rectangle, pad it, select the top face of the rectangle, create a new sketch, in the new sketch draw a circle, close the sketch, then pocket it?
Yes. All of the above.
drmacro wrote: Mon Mar 16, 2020 6:16 pm I'm guessing the stuff that you can't get to be identical to the tutorials is beyond these things and are confusing you needlessly. (And, note, I'm not chastising here, I get it, I used to teach this CAD stuff for a living to Oooooold engineers (like ones who grew up using drafting boards and slide rules.) ;) )
You are probably correct that things I don't necessarily need are confusing me. I'm not going to get into an age ****ing contest, but I do go back to the days of core memory. My master's thesis was a primer on microprocessors that was an expansive review of the entire industry. IOW, about what a 10 y.o. gets in grade schools these days. But unlike Michael O., I have conveniently forgotten how to use a sliderule. :lol:

I'm going to try to create a video that shows some of my problems. Hopefully, back today.

Thanks!

Dave
dave_w
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Re: OK, I'm Stuck... Complete Newbie

Post by dave_w »

dave_w wrote: Mon Mar 16, 2020 10:06 pm I'm going to try to create a video that shows some of my problems. Hopefully, back today.
Sorry, I'm not a PC expert. Here's a video, no audio, and no visible cursor:

https://www.youtube.com/watch?v=RMYP0ZjdLKs

Here's what I've done:

New doc

New body

New sketch

New rectangle

Select upper left, vertical center line, upper right.

Select "><"

Here was/is a source of confusion. At first I didn't see the conflicting constraint. Once I did, I could delete it and move on. But why was it created? Tutorials show this same sequence shifting the rectangle to the center line. The same thing happens when trying to center on the horizontal line. Is there a configuration somewhere that does this?

Before seeing the conflicting restraints, I could not set the horizontal or vertical dimensions by selecting the line and appropriate icon. Now I understand why, except why the constraints were created in the first place.

Dave
drmacro
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Re: OK, I'm Stuck... Complete Newbie

Post by drmacro »

dave_w wrote: Tue Mar 17, 2020 4:50 pm
dave_w wrote: Mon Mar 16, 2020 10:06 pm I'm going to try to create a video that shows some of my problems. Hopefully, back today.
Sorry, I'm not a PC expert. Here's a video, no audio, and no visible cursor:

https://www.youtube.com/watch?v=RMYP0ZjdLKs

Here's what I've done:

New doc

New body

New sketch

New rectangle

Select upper left, vertical center line, upper right.

Select "><"

Here was/is a source of confusion. At first I didn't see the conflicting constraint. Once I did, I could delete it and move on. But why was it created? Tutorials show this same sequence shifting the rectangle to the center line. The same thing happens when trying to center on the horizontal line. Is there a configuration somewhere that does this?

Before seeing the conflicting restraints, I could not set the horizontal or vertical dimensions by selecting the line and appropriate icon. Now I understand why, except why the constraints were created in the first place.

Dave
I don't get conflicting constraints selecting as you did. But, that is because I have (in the Solver messages pane) "Auto remove redundants" checked.

Some notes:
- I always select the points, then the thing that I want them centered around. In your case the vertical axis line. (Hint: If, you want the box centered around the origin, select the upper left, lower right and the center origin point.)

- If there is a horizontal or vertical constraint on a line, I dimension it with the length
length_dim.png
length_dim.png (858 Bytes) Viewed 864 times
dimension. A horizontal/vertical
HorVer_dim.png
HorVer_dim.png (698 Bytes) Viewed 864 times
dimension implies a horizontal/vertical distance between the end points of the line. (note: I don't know if it makes any difference, but it is my personal preference. Well, and I think can in certain instances...)

- I usually avoid the lock constraint, though it is a quick way to get a dimension in both axes.

- avoid using the line
Line_icn.png
Line_icn.png (643 Bytes) Viewed 864 times
function because it is difficult to get every end point coincident. So, I tend to use the rectangle or polyline. With the later, when done adding lines, I then select the first point and last point and add a coincident constraint. (A hint: if you make two over lapping rectangles or overlapping other shapes, then the "trim edge" will automagically add coincident points at the cut.)
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
chrisb
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Re: OK, I'm Stuck... Complete Newbie

Post by chrisb »

dave_w wrote: Tue Mar 17, 2020 4:50 pm At first I didn't see the conflicting constraint. Once I did, I could delete it and move on. But why was it created?
Symmetry of two points to a line implies in case of the line being vertical that the points are horizontally on the same level. Thus the horizontal constraint is redundant. The same just vice versa holds for vertical lines.
Tutorials show this same sequence shifting the rectangle to the center line.
These are old tutorials, where the solver did not show the message. I discourage to remove the redundancies automatically, because you may not really understand how constraints work. In my (slightly outdated) Sketcher tutorial this is explained in some depth, and I recommend to always watch the solver messages. For me it is a small victory every time the number of degrees of freedom decreases. If an error is shown you should react immediately.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
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