Mass Properties Question

Hi all,

Hopefully this a fairly simple answer one way or another:

I am trying to assign a constant value to the mass properties of an object without having to write a LISP.

For Example: If I have a cube, I can easily determine the area volume mass etc. from the MASSPROP command. However, what if I want to determine the WEIGHT of that object if it is made of glass, steel, concrete etc.?

Right now I am forced to take the mass and jump to a physical calculator and do the rest of the math.

If I have the weight per square inch of a certain material is there a section within CAD that I can drop this number so that it shows me the weight of that object if it were to be made of that specific materal?

As dumb as it sounds I feel like there should be an actual PROPERTIES section within the MASSPROP command that allows the user to enter these things in.

Any ideas?

Thanks in advance for your help!

AFAIK, AutoCAD simply uses assumes a material density of 1, while Inventor takes the actual material into consideration.

There may be an add-on for AutoCAD. There was one for R14 (circa 1997).

Ya that's what I am starting to realize.

Its just odd though because I am not even asking CAD to supply the weights, I have them.

I just want to automate the process so that I am not getting 75% of the information from CAD and then the other 25% by hand.

I am trying to streamline it and eliminate errors.

You can set up custom Variables below your calculator, use *............, and fill in with the mass of the material in question.

You will still need to copy and paste from massprop into your quick calculator, then click on the variable and hit = .

Not great but will stop you having to remember or enter all of the different material masses each time.

That is helpful Dadgad, I may have to resort to using this.

If I were to resort to a LISP, is there a command that would allow me to pull the VOLUME amount from the mass properties?

Sort of like a GETPOINT command but able to retrieve the volume amount. This way I could do the math right within the program.

Give this LISP a try...http://cadtips.cadalyst.com/mass-properties/determine-weights-3d-objects

SLW210,

I realized how ridiculous this is going to sound but for some reason when I click on that link there is nowhere for me to dl the lisp.

I see where it says "WEIGHT.LSP" but it is not a hyperlink.

Do I have to have an account through cadalyst in order to dl this?

SLW210,

 

 

I realized how ridiculous this is going to sound but for some reason when I click on that link there is nowhere for me to dl the lisp.

 

 

I see where it says "WEIGHT.LSP" but it is not a hyperlink.

 

Do I have to have an account through cadalyst in order to dl this?

No, I don't believe you do, I liked the look of this lisp, so I just downloaded it, but you will need to scroll to the second page of downloads.

I didn't sign in, and was able to download it.

Good tip SLW, thanks.

SLW210,

 

 

I realized how ridiculous this is going to sound but for some reason when I click on that link there is nowhere for me to dl the lisp.

 

 

I see where it says "WEIGHT.LSP" but it is not a hyperlink.

 

Do I have to have an account through cadalyst in order to dl this?

Click on "DOWNLOAD THIS TIP" at upper right next to the Print Icon.

This is a cool lisp, but I just tried it, and it only supports Imperial units as written,

Were I not so tired, I would try to tweak it so as to embrace Metric volumes, perhaps on the morrow.

Dadgad before you tweak it, Mechanicalanimal what materials do you use you could shorten the material list to suit.

A chart http://mojobob.com/roleplay/weight_chart.html

Dadgad before you tweak it, Mechanicalanimal what materials do you use you could shorten the material list to suit.

 

A chart http://mojobob.com/roleplay/weight_chart.html

Thanks BIGAL, very helpful, that will save me having to think too much about the conversions.