Two basic questions

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moltenaxe
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Joined: Fri May 10, 2013 8:03 pm

Two basic questions

Postby moltenaxe » Fri May 10, 2013 8:10 pm

Hello everyone, I am in a bit of a pickle here as I have received a 3D model with the .step extension, so I had to download FreeCAD, as I have no other programs that can open them.
Now, what is only important about this for the timebeing is that I would like to calculate the mass/volume of the 3D and how to display the measurements. Trust me, I attempted to look online, I have tried messing around with the program for a couple of hours, but I cannot find the precise measurements (without using the manual measuring tool) and the mass - if the program is capable of doing so in the first place.
So, the questions are kind of obvious:
How do I see precise measurements that were put in originally?
How do I calculate the mass/volume of the model with the program?
I would appreciate it if you could describe in as much detail as possible, as when I last tried to even put it into 2D in one view, the model jumped completely off the sheet and I could not see it nor interact with it.
I would like to thank you for your support in advance as it is more or less an urgent matter.
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NormandC
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Re: Two basic questions

Postby NormandC » Sat May 11, 2013 1:40 am

Hello,

When asking for help, please always mention your FreeCAD version, including the 4-digit revision number. The current stable version is 0.13.1828 for Windows and 0.13.1830 for Linux. Also mention which operating system you are using. BTW this is all spelled out in the "Read first before asking for help" topic which is at the very top of this forum...
moltenaxe wrote:How do I see precise measurements that were put in originally?
A STEP file is a neutral exchange format and to my knowledge, you cannot access the "precise measurements" that were put originally. When exporting to STEP you loose any kind of intelligence or parametric features that were created by the CAD program used to model it.

When importing a STEP file into any CAD program, measurements cannot be "displayed", they have to be taken with a set of specific inspection tools. Unfortunately those tools are not currently included in FreeCAD's GUI apart from the very limited measurement tool (the tape measure icon). I do not trust it because it is very easy to click off a vertex instead of exactly on it and this makes the measurement imprecise.

Truth is, FreeCAD is a project done by volunteers in their spare time, efforts are being directed toward geometry creation which is the core reason of the project. You can get some information through the python console but you've got to write commands which I am not familiar with (I'm really not a console kind of guy!)

You can get volume but mass is not supported yet, as material management has yet to be implemented. A FreeCAD user created a user-friendly "Info" module which you can get here: http://www.sloan-home.co.uk/FreeCAD/Info/Info.html

If you're on Linux, you need to create a folder named "Mod" in the .FreeCAD hidden folder which is located in your Home folder. Then create a folder named "Info" in the "Mod" folder, and extract the content of the archive in it. On Windows, I have no idea where that would be. I guess it may be in C:\Program Files\FreeCAD\Mod.

Then start FreeCAD, open your STEP file and switch to the "Info" workbench with the workbench switcher or by going to the View --> Workbench menu. Now select your solid, and click on the "Info" icon; the left taskbar will show some information on the model, including volume, surface area, center of mass and moment of intertia.

As for taking measurements, I've developed workarounds for my purposes, but they are convoluted and require learning quite many tools and it would take much explanation. One way that may be enough for your needs is to use the Draft Dimension tool from the Draft workbench. Look for it in the wiki: http://www.freecadweb.org/wiki/index.ph ... =Main_Page
moltenaxe
Posts: 4
Joined: Fri May 10, 2013 8:03 pm

Re: Two basic questions

Postby moltenaxe » Sat May 11, 2013 11:58 am

[quote="normandc"][/quote]
I apologise, I must've forgotten to include that, but I am/was using the most recent stable version; which is 0.13.1828.
Thank you very much for your help. I will look into it immediately and see if it will solve my problem as volume is pretty much the most important factor here when it comes to reading the model for me.
Edit: Well, seems that the link does not work for me. I will try it again later.
moltenaxe
Posts: 4
Joined: Fri May 10, 2013 8:03 pm

Re: Two basic questions

Postby moltenaxe » Sat May 11, 2013 2:14 pm

It works now and I have successfully installed the module, as well as used it to check the volume. I assume it is in cubic millimeters since everything else is in millimeters by default, right?
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NormandC
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Location: Québec, Canada

Re: Two basic questions

Postby NormandC » Sat May 11, 2013 3:43 pm

Yes, it is in cubic millimeters.
moltenaxe
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Joined: Fri May 10, 2013 8:03 pm

Re: Two basic questions

Postby moltenaxe » Sat May 11, 2013 7:21 pm

normandc wrote:Yes, it is in cubic millimeters.
Well, that covers about everything I needed to know. Thank you very much for your help.