Can someone help me determine this 3d object for .999 fine silver Size?

I have this 3d obj mushroom file and need to weight in a 1 ,2 5 and 10 oz .999 fine silver Size. Can anyone help me determine what exact size for each from bottom of mushroom to top of mushroom in height to achieve these specific weights in .999 silver please? I can send someone the obj mushroom file . I do not see a link here to include the said Mushroom obj .

Hello Mpix00,

To upload a file use this icon:


I think you will see it if you just reply to this post. Or just use:


Thank you,


mush.000.obj (828.6 KB)

Here is the obj.file that I need help with

Thank you, I just uploaded the file;)

Hello - fine silver density seems to be
10.49 g/cm³

So, scaling your object should be pretty straightforward.


The 3 d mushroom object has different thickness throughout the length. So forgive my ignorance, but how would I go about figuring out the correct scale? A troy oz of silver weighs 31.1 grams. I did 2 test pours. The Larger I poured is 1.458" from bottom of stem to top of mushroom that weighs134.4 grams or 4.32 Troy Oz . The smaller is .922" in height and weighs 33.7 grams or 1.08 Troy oz
How would I take those measurements to find the specific size for the 2,5 and 10 oz weight?

Hello - if I import your file into a cm template file, I get a volume for the mushroom of 6.2 cm^3. At 10.49g/cm^3, that is, as is, 65.04 grams of silver. You need to find the volume that will be say 2 oz, (= 62.2 g,) which, it looks like, will be just a bit smaller than what you start with.

62.2/10.49 = 5.93 cm^3 is your target volume for 2 oz…

Does that make sense?


Yes that does make sense, but my problem is that I have no way to determine my target volume on my end. My program does not do that. So I am hoping that someone here on this forum could help me out to find the exact target volume for a 1,2 5 and 10 oz fine silver size and let me know the height of the mushroom in inches for each of the targeted volumes of the 1,2 5 and 10 oz required size.

You can determine the target volume -

10oz *31.1 g per oz = 311 g target weight … right so far?

At 10.49 g/cm^3 that is 311/10.49 = 29.65 cm^3 <<<<< target volume

So, you need to scale from the current 6.2 cm^3 to 29.65 cm^3

Which is 4.78 times larger in volume.

So 3d scale factor is the cube root of 4.78… if I am thinking clearly. Scale your object by 1.685


That is for the 10 oz size correct? Scale it up 1.685 If I am understanding you clearly? What about for the 5 ,2 and 1 oz size?

Hello- if I got it right, just repeat the process for the other sizes.


How did you get the 1.685 Scale number?>

okay I found a cube root calculator. Thank you

FOr the 2 oz my target volume would be 5.93 cm cubed. If the target volume for the 2 oz at 5.93 is less than the initial volume of 6.2, do I divide 5.93 from 6.2 or do I divide the 6.2 from 5.93?

okay so you were actually a bit off . Once I made a mold of my mold at the taget 3d object, then I poured my silver intothe mold and weight the mold in troy oz. The model actually weighed at 4.32 oz which is slightly smaller than 5 oz, so I actually had to enlarge the model just a tad to reach the 5 oz mark;) Thank you though , as I am now using the calculations to figure out the other sizes that I need;)

Fwiw, my plugin lets you size objects to a target weight/mass. You have to run RealMaterialTools first, then ScaleObjectToSpecificMass.

Will that work using the calculations of a 1 Troy oz of Silver size which is 31.1 grams to calculate a 3d object?

Also, will I need rhino 6 or 7 to use this plug in correct?

Actually, right now the options are ounces (0.035274 per gram) or pennyweights. So if you want to use troy oz you are out of luck with my plugin. It works in rhino 6 & 7.

You can use this button - it works with troy ounces and remembers settings.

Quick Mass Tools.rui (13.8 KB)