Constraints in Sheet Metal?

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frnq
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Joined: Sat Jul 16, 2022 9:58 am

Constraints in Sheet Metal?

Post by frnq »

Hi all,

I'm new here. Let me shortly introduce myself. My name is Frank and I am from the Netherlands. I'm working on restoring an old International truck from 1929. Which is awesome. Yes such a small truck you see in very old movies.
As you can understand some parts are gone and need to be rebuild. So I started drawing on paper. But as an engineer, I'd like to have all the details right so I started looking for CAD software to make some 3D drawings. I am in now way a mechanical engineer. My specialism is electrical and automation engineering.

So I started with FreeCAD. I already can use it "okayish". I am using the plugin Sheet Metal in FreeCAD 0.19 to draw a Battery Tray.

Now my question:
In the Sketcher environment you have constrains. And with that the drawing "listens" to these contrains. Is that also possible for the Sheet Metal add-on? So the angles and lenghts and thicknesses are a result of these constrains?
Last edited by Kunda1 on Sat Aug 27, 2022 5:32 pm, edited 1 time in total.
Reason: fixed typo in thread title
chrisb
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Re: Constrains in Sheet Metal?

Post by chrisb »

Hi and welcome to the forum!

You can give names to dimensional constraints and use them in Expressions. If you don't have a dimension at hand, you can create a (blue) driven constraint and give it also a name.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
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papyblaise
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Re: Constrains in Sheet Metal?

Post by papyblaise »

SheetMetal uses the same elements as the other workshops
Often the first element is a sketch, then the successive steps behave like Pad in many aspects
chrisb
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Re: Constrains in Sheet Metal?

Post by chrisb »

frnq wrote: Sat Jul 16, 2022 10:07 am I'm working on restoring an old International truck from 1929.
I would like to see some pictures.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
frnq
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Joined: Sat Jul 16, 2022 9:58 am

Re: Constrains in Sheet Metal?

Post by frnq »

@chrisb here you are.

Attached is also my battery tray Freecad file. And a photo how the rusted out part looks like. As everything is very old and crooked, the measurements are not easy.
First of all these parts are in American units. So all in inches and fractions.

My problem here is the angled parts. The angles and lenghts do not add up. That in combination with the corners of the sheet metal, the fractions in the Imperial System give me headaches ;)

The bottom bracket, I know the height and the width. But how do I get it to act that it listens to the height and width. In Sketcher you set a total height and a height for the straight part and the rest is a result. If I could do that for the bottom part and for the vertical part then the corner and lenght of the angled part would be the results of these constrains.
Attachments
Battery Tray v2.2.FCStd
(108.67 KiB) Downloaded 15 times
IMG_20220716_140930 (2).jpg
IMG_20220716_140930 (2).jpg (978.71 KiB) Viewed 740 times
20190316_102340.jpg
20190316_102340.jpg (507.5 KiB) Viewed 748 times
1 International six speed 0521 (1).jpg
1 International six speed 0521 (1).jpg (772.26 KiB) Viewed 748 times
International six speed 1197.jpg
International six speed 1197.jpg (856.49 KiB) Viewed 748 times
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Shalmeneser
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Re: Constrains in Sheet Metal?

Post by Shalmeneser »

You should use SheetMetal_AddBase : easier & quicker.
Attachments
Capture d’écran 2022-07-16 144243.jpg
Capture d’écran 2022-07-16 144243.jpg (63.73 KiB) Viewed 733 times
Battery Tray _SHALM.FCStd
(42.35 KiB) Downloaded 15 times
frnq
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Re: Constrains in Sheet Metal?

Post by frnq »

Shalmeneser wrote: Sat Jul 16, 2022 12:44 pm You should use SheetMetal_AddBase : easier & quicker.
Yes! That is what I need. Thanks a LOT!
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Willem
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Re: Constrains in Sheet Metal?

Post by Willem »

I also made a battery bracket. Shalm was faster
Attachments
BatteryBracket.FCStd
(35.23 KiB) Downloaded 14 times
chrisb
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Re: Constrains in Sheet Metal?

Post by chrisb »

Nice project!

I wouldn't use for such a task the SheetMetal Bends at all. In the attached example I created for the Bottom Plate a sketch with the straight lines, added fillets in the sketch and then used SheetMetal>BaseBend.
Attachments
BatteryTray_cb.FCStd
(19.74 KiB) Downloaded 18 times
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
chrisb
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Re: Constrains in Sheet Metal?

Post by chrisb »

Willem wrote: Sat Jul 16, 2022 1:58 pm I also made a battery bracket. Shalm was faster
:lol: Here too!
However, it should be rather convincing that BaseBend is the way to go.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
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