Best way of doing this?

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christianitis
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Joined: Tue Jul 27, 2021 3:07 pm

Best way of doing this?

Post by christianitis »

I am building a work table. The surface is a simple polygon that I built from a sketch on the XY plane, no problem there.
For the legs and supports, I am using a common structure: a 1"x1" hollow square tube. I use 6 for the legs, and ~10 for the supports. The length of each instance differs and is thus unimportant to this question, just know that the base structure stays the same. I have attached photos of this base structure. Each support is an individual part, which I will then weld together when I begin construction to create the frame.

The problem arises when I try to position these correctly. I figured this would be simple because they are all the same shape, only sometimes differing in length and direction, but I was wrong. First, I tried making an initial "template", then copying it each time and repositioning them as Bodys in the PartDesign workbench. This took up quite a lot of time, and I realized I wasn't actually "attaching" them to eachother, just changing the position of each so they visually matched up. Plus, I seemed to be copying a lot of dependencies as I went on and was getting my Combo View clogged up with seemingly useless items. I tried a bunch of different techniques/workflows to keep everything nice, tidy, and parametrized, but none seem to be working well.

So what would be the best way of completing this project? The way I was doing it "worked", but it was messy, inefficient, and required a lot of effort. There must be a better way, right?

OS: openSUSE Tumbleweed (KDE//usr/share/xsessions/plasma5)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.Unknown
Build type: Release
Python version: 3.8.10
Qt version: 5.15.2
Coin version: 3.1.3
OCC version: 7.5.1
Locale: English/United States (en_US)
Attachments
support sketch.png
support sketch.png (13.96 KiB) Viewed 885 times
padded.png
padded.png (11.78 KiB) Viewed 885 times
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papyblaise
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Re: Best way of doing this?

Post by papyblaise »

For me, even after 25 years of CAD, the fastest formula is to redo the profile in each direction, even if they are identical profiles
and, I will do it with Part
for fun, i tried with PartDesign, but to do the miror, i only succeeded with Part
Attachments
table.PNG
table.PNG (16.23 KiB) Viewed 858 times
christianitis
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Re: Best way of doing this?

Post by christianitis »

papyblaise wrote: Tue Jul 27, 2021 4:59 pm For me, even after 25 years of CAD, the fastest formula is to redo the profile in each direction, even if they are identical profiles
and, I will do it with Part
for fun, i tried with PartDesign, but to do the miror, i only succeeded with Part
That sounds fair, but I can't even properly copy it for legs in the same direction. I used a ShapeBinder so I could attach the sketch to the bottom surface of the table, but when I copy and paste the leg it A. brings along a bunch of dependencies outside the body which is a pain to clean up and B. The ShapeBinder seemingly doesn't work because I am seemingly unable to reference geometry on the table surface like I was before. I guess it will all have to be in one body now, which makes things a little awkward I guess. Devs pls fix

Image
I think the devs do a little trolling, it's called they do a little trolling.
Bance
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Re: Best way of doing this?

Post by Bance »

You could try DoDo addon....

https://www.youtube.com/watch?v=oh0OG81R8Kw
chrisb
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Re: Best way of doing this?

Post by chrisb »

When copying you should carefully inspect the list of dependencies before confirming the copy process. Instead of copying, I would rather use a Draft->Clone.
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chrisb
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Re: Best way of doing this?

Post by chrisb »

And concerning your sketching:
- minimize the number of measures in favour of geometric constraints
- use symmetry to center the rectangles.
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Shalmeneser
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Re: Best way of doing this?

Post by Shalmeneser »

* Symmetry of opposite corners with O
* Equality of length

(btw, my Sketcher doesn't want to follow Preferences modifications. How can I fix that ?)

Code: Select all

OS: Windows 10 (10.0)
Word size of FreeCAD: 64-bit
Version: 0.20.25311 (Git)
Build type: Release
Branch: master
Hash: c5524bb58a7126fa2242d6137eb82ee9d54e82d4
Python version: 3.8.10
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.2
Locale: French/France (fr_FR)
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BarreDeFer.png
BarreDeFer.png (10.81 KiB) Viewed 713 times
TheMarkster
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Re: Best way of doing this?

Post by TheMarkster »

Just for fun, a sketchless version using Part workbench primitives and Draft clones and arrays.

basic_tube is the template for the other tubes. It is the cut result of cutting a smaller cube out of a larger one. Both are 1" tall to make it easy to scale the clones. For example, long_tube is 6' long, so it's scaled z = 72 (for 72 inches since 6 * 12 = 72).
Snip macro screenshot-77dc4c.png
Snip macro screenshot-77dc4c.png (108.07 KiB) Viewed 659 times
Snip macro screenshot-ac69bd.png
Snip macro screenshot-ac69bd.png (116.09 KiB) Viewed 659 times
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square_tube_table.FCStd
(45.92 KiB) Downloaded 18 times
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M4x
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Re: Best way of doing this?

Post by M4x »

Shalmeneser wrote: Tue Jul 27, 2021 11:05 pm (btw, my Sketcher doesn't want to follow Preferences modifications. How can I fix that ?)
Could you open a new thread regarding this topic? Does it only effect the Sketcher?
chrisb
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Re: Best way of doing this?

Post by chrisb »

Shalmeneser wrote: Tue Jul 27, 2021 11:05 pm (btw, my Sketcher doesn't want to follow Preferences modifications. How can I fix that ?)
Some of the preferences are defaults for new sketches. You can apply them in the preferences to existing ones. If you mean that an open Sketcher doesn't take other changes such as font size into account: I am very sure that this has to be fixed in the C++ code.
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