Body vs Part

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KevCan
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Joined: Tue Jul 31, 2018 6:38 am

Body vs Part

Post by KevCan »

Hello, hoping someone could help with best practice and give me some ideas.

I am to make a component that consists of 3 separate pieces that I will 3D print and fit together.

Let's say my component is a motor housing and is made of 3 pieces called a "fixing plate", a "box", and a "lid".

Up until now, I have been creating individual 3 files called "fixing plate", "box", "lid". Each file contains a single freecad "body".

Once I have designed each body, I will see how each of the 3 pieces fit together and construct a virtual component using the add-on "A2Plus V0.4.54b". From here I move and edit each body as required by updating each of the 3 files as appropriate.

I see that in freecad, I can "Create New Body" and also "Create New Part". I've avoided "Create New Part", but as I get more confident with freecad I though my next design I'd see if I should be doing this differently.

How do others use freecad? I wondered if I should be creating just 1 file, that contains 1 "part", and 3 "bodies". What do other people do? Is there a "right" way, or "better" way to do this than I am at present?

I tried this in the past, but moving each body so that they fit together as part seemed cumbersome so I went with the add-on "A2Plus V0.4.54b" which made more sense to me. Particularly as I will eventually print each part.

Any thoughts? Just curious if I can learn something new.

Thanks Kev

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thomas-neemann
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Re: Body vs Part

Post by thomas-neemann »

KevCan wrote: Sat Nov 26, 2022 4:36 pm ...
i like to work with the top down method. here are some examples


https://www.youtube.com/watch?v=BLRhjn2cytE

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drmacro
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Re: Body vs Part

Post by drmacro »

KevCan wrote: Sat Nov 26, 2022 4:36 pm ...
The Part (Std_Part) is a container. It can contain Part workbench solids, Part Design workbench Body's, and other solids like STEP imports.

The things in the Std_Part will move with it when it is moved. It is useful, for example, if you have a few components that you wish to remain in their relative positions, but be able to move them as a whole.

When you create a PD Body, you have defined a container that will contain a single, solitary, cumulative solid. Each feature (Pad/Pocket/etc. operation) in the Body is cumulative (and the result of each feature is NOT an atomic solid). The result of each feature MUST result in a single solitary solid (that is an accumulation of it's predecessors). In other words, each of your pieces could be thought of as a Body.

Rather than using an assembly workbench for a few pieces, make each in a Body and you could use Manipulator workbench to place and align them. Then create a Std_Part and drag-n-drop them into it.

After that you can move the Std_Part.
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chrisb
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Re: Body vs Part

Post by chrisb »

If I have only several bodies, I donb't use a Part container.
For bigger models I use Part containers for sets of bodys which belong together. This can be seen as an assembly. The Part container groups the bodies and provides the possibility to move them alltogether.

I transfer geometric information from one body to another by ShapeBinders or Expressions.
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KevCan
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Joined: Tue Jul 31, 2018 6:38 am

Re: Body vs Part

Post by KevCan »

chrisb wrote: Sat Nov 26, 2022 6:47 pm If I have only several bodies, I donb't use a Part container.
For bigger models I use Part containers for sets of bodys which belong together. This can be seen as an assembly. The Part container groups the bodies and provides the possibility to move them alltogether.

I transfer geometric information from one body to another by ShapeBinders or Expressions.
Thanks, this helps. I'm using ShapeBinders more and more
KevCan
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Re: Body vs Part

Post by KevCan »

drmacro wrote: Sat Nov 26, 2022 5:54 pm
KevCan wrote: Sat Nov 26, 2022 4:36 pm ...
The things in the Std_Part will move with it when it is moved. It is useful, for example, if you have a few components that you wish to remain in their relative positions, but be able to move them as a whole.
...
Rather than using an assembly workbench for a few pieces, make each in a Body and you could use Manipulator workbench to place and align them. Then create a Std_Part and drag-n-drop them into it.

After that you can move the Std_Part.
Nice one-I'm starting to understand better now. I'd not seen Manipulator either. I've added it, and I'm playing with that to understand better. Thanks this is all helpful.
tadeuszd
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Re: Body vs Part

Post by tadeuszd »

KevCan wrote: Sat Nov 26, 2022 4:36 pmHow do others use freecad? I wondered if I should be creating just 1 file, that contains 1 "part", and 3 "bodies". What do other people do? Is there a "right" way, or "better" way to do this than I am at present?
Please imagine, that "Bodies" are apples (fruits) and "Part" is a box.
If you have a few apples, you can manage them one by one. But in large projects it is good idea to pack apples into boxes and move/rotate/transform them using boxes. You can also pack small boxes into large box. If you move/transform this large box, all small boxes with apples wil be moved/transformed to new place (new coordinates). Simple... ;)

In your situation, 3 bodies should be in 1 file. Grouping in "Part" is not necessary, until you plan to use your work in more complex assembly.
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