PDA

View Full Version : volume to weight?



Revanto
11-26-2008, 12:38 AM
OK, this is a really weird request. I went to a jewellers today to get a quote on an object for which I'm going to make into jewelry. He used JewelCam to check my sample object. The program was also capable of finding out the weight of an object based on the volume (I'm sure the type of metal was part of the equation somewhere) which let him know how much metal would be used for the final print.

I was wondering if anyone knew of a plugin or a third party piece of software (free, of course) that could determine the weight of an object based on volume.

Like I said, this is a weird request.

Any help would be appreciated.

Cheers,
Revanto :p

Stunt Pixels
11-26-2008, 12:46 AM
Never heard of such a thing. But there is at least one plugin that calculate the volume... If you know the weight/volume ratio, it should be easy to figure out. Check out AreaVolume (http://home.comcast.net/~erniew/getstuff.html)

biliousfrog
11-26-2008, 09:54 AM
A guy that I do off-shore work for told me about the software that all of the rig designers use which works by mass and volume. All of the components have physical characteristics so that they can determine weight and stress. A friend in the automotive industry uses a similar system, it's not uncommon.

Revanto
11-26-2008, 08:33 PM
Never heard of such a thing. But there is at least one plugin that calculate the volume... If you know the weight/volume ratio, it should be easy to figure out. Check out AreaVolume (http://home.comcast.net/~erniew/getstuff.html)

I don't know how to calculate this. I tried the plugin and got a volume but I have no idea of what to do with that number. I tried converting the volume using a program called "Conversion Buddy" but all I got was the option of converting to wet measurements IE litres, gallons, etc...

I suck at math but if you gave me a simple formula to follow, that would be useful.

Thanks.

Cheers,
Revanto :p

Sensei
11-26-2008, 09:03 PM
Destination_Weight = Object_Volume * Reference_Weight / Reference_Volume?

f.e. 1 meter square of water is approximately 1 ton.
if volumes are in meters then it's f.e.:

40 meters * 20 meters * 10 meters = 8000 meters square
8000*1/1 = 8000 tons of water is in box size 40x20x10

140 cm * 55 cm * 40 cm = 1.4 m * 0.55 m * 0.4 m = 0.308 ton = 308 kg of water in typical bath..

Stunt Pixels
11-26-2008, 09:13 PM
OK, I suck at math too... But I'll give it a go though - anyone feel free to correct me.

The plugin calculates area by cubic meters. I'm guessing with gemstones, cubic cm would be more useful. 1 cubic meter = 1000000 cubic centimeters. If you multiply the plugin's returned result by 1000000, you will get cubic centimeters. Multiply that by the specific gravity of the stone, and you're done.

Here's an example with a dodgy little doohicky I made...

Returned volume was 8.59006e-007 cubic meters.
Multiply that to get cubic centimeters: 0.000000859 * 1000000 = 0.859006 cubic cm.
Look up the specific gravity (http://www.csgnetwork.com/gemchar.html) of diamond: 3.51
Multiply volume by specific gravity: 0.859006 * 3.51 = 3.015111 grams

And, if required,
Multiply grams by 5 to get carats: 3.015111 * 5 = 15.075555 carats

I think... Seems about right to me. Anyone?

george49
11-26-2008, 09:42 PM
Destination_Weight = Object_Volume * Reference_Weight / Reference_Volume?
f.e. 1 meter square of water is approximately 1 ton.
if volumes are in meters then it's f.e.:
.

Are you sure that a meter-squared of H2O weighs a ton? I've read that a gallon of water weighs about 8 pounds, and at work we use 5 gal water containers for drinking. The bottles therefore should weigh about 40 pounds and they are are fairly good size. A ton of water should contain about 50 of these bottles and that seems like an awful lot

George

Sensei
11-26-2008, 09:52 PM
Are you sure that a meter-squared of H2O weighs a ton?

Yes, that's quite well known thing
http://www.engineeringtoolbox.com/water-density-specific-weight-d_595.html
1 g/cm3, 1000kg/m3..
But it depends on pressure and temperature..

Sensei
11-26-2008, 09:58 PM
Of course, I meant meters cubic, not square.. square is 2 dimensional, not 3 dimensional..

Revanto
11-29-2008, 01:57 AM
OK, my brain's spinning.

The volume of the object is 1.31501 cubic meters according to the plugin. So does that make the weight 1.31501 cubic litres?

How do I turn that into grams?

I know, I must be one of the stupidest people but I just want to make this clear.

The dimensions of the object's bounding box of the object is:
X = 16.45 mm
Y = 29.165 mm
Z = 6.1582 mm

But since the object does not take up the whole space within the bounding box, I'm not sure if the dimensions match up to the volume I mentioned at the start of this message.

Thanks to everyone so far, BTW.

Cheers,
Revanto :p

Revanto
11-29-2008, 02:40 AM
Sorry, the volume of the object is 1.31501e-6. I thought 'e' referred to an error margin but discovered it meant 'exponent'. Like I said, I suck at math.

Revanto

kopperdrake
11-29-2008, 03:16 AM
Hey Revanto - you can't use the object's bounding box to work out its volume - you need to run that plugin someone mentioned above to get your object's volume.

If you wanted to know the volume of your bounding box then it's just: Width x Height x Depth.

In cubic millimetres it would be: 16.45mm x 29.165mm x 6.1582mm = 2,954.5 cubic mm

For cubic metres, just convert the original mm dimensions to their metre equivalents (ie 16.45mm is now 0.01645m). It'll go something like this: 0.01645m x 0.29165 x 0.061582 = 0.0002954 cubic metres.

You then just need to find out the weight of gold per cubic metre and multiply it by that last figure to get the weight of your bounding box in cubic tons.

Revanto
11-29-2008, 04:23 AM
OK, I'm using the plugin and Lightwave's native measurements but I think they are wrong. I found out from the jewellers that my 3cm tall object imported at something like .03 of a millimetre. They sized it up and used Jewelcad (not "JewelCam" as I first thought) to determine the weight which came to about 15 grams. Now I don't know if Jewelcad utilises metal density but the whole makes me feel like Lightwave is not exporting correctly to real life dimensions.
This means that I will have to scale up my objects to ??? the size before exporting.

Does anyone know about this flaw or is it something common?

I'd rather if the jewellers didn't have to do any rescaling on my account. I would rather export at the right real-world dimensions.

Revanto