area/volume

[Michael Reynolds]

When I analyze a solid to, say, determine the volume it will hold (like a bottle), it gives me a volume, but what are the units it gives them to me in? Are they litters (sp)? If so, how can I change them to quarts, or gallons?

Thanks all!

Hope everyone is having a good 4th!

I'm working, myself, but having fun at the same time! (Today I can play on Mcam -n- have a beer at the same time!!!!!

Thanks again!

Mike R.

[gcode]

Mike I suspect that the units of volume are probable in the same units you are drawing with.

(Probably cubic inches)

To find out do an experiment.

Create a solid cube 1.in by 1.in by 1.in

MC should return a volume of 1 (cubic inch)

You'll have to break out a conversion table

to turn cubic inches to quarts

[Michael Reynolds]

I'll give it a shot.

Thanks Gcode!!

Mike R.

[Charles Davis]

The volume is just that, the in^3 or mm^3.

To get the weight, you have to know the density of the material in lb/in^3 or kg/mm^3.

For example, the density for aluminum is about .101 lb/in^3. Just plug that number in the Density field to get the weight of your object.

Getting the density in the units you need can be tricky. For example, the density of aluminum could be given in lb/ft^3. If you don't remember, you'll have to dig out an old physics or math book to make sure you do the conversion properly. Make sure you do a very simple example first (a common sense type example) to confirm you've got the right numbers coming out before trusting your density value.

There is a terrific shareware units converter called convert.exe that will do that for you. It properly converts just about anything to just about anything else.

Search for this on the internet.

[Michael Reynolds]

so, like not to be 'pid, but what's the density of water?

Thanks,

Mike R.

[BernieT]

 

This looks like a great web site. appears to convert anything to anything else.

 

http://www.convert-me.com/en/

[gmenzies]

hello

i read your post on volume calculations and see you are a teacher. I do this on a daily

basis .

I always work metric , so calculations are always simple.

1 liter water = 1000 grams

i use a metric conversion calculator and convert the cubic inches to cubic centimeters.

when i have to calculate a volume of a bottle . i take the volume calculated by the

solid model and subtract the wall thickness .

to achieve this i use specific gravity . example: HDPE is .94 gm/cm3

the inverse or (specific volume) 1/.94 cm3/gm = 1.063

then i take the bottle weight example 50 grams material X 1.063 =53.15

then i take the volume calculated by the solid model example: 1663 cm3

1663 - 53.15 = 1609 .85 mls of water to the brim of bottle.

this system give me a fairly constant fill levels. bottles that are made in the plastics industry do not always follow the rules of math.

hope this helps with your calculations

[Charles Davis]

The density of water is 1000kg/meter^3

Using the convert utility, that's equal to .036127 lb/in^3.

Plug .036127 into the Density field in the Analyze, Area/Volume, Solid Props, and the weight result will appear in the Mass field.

 

[Michael Reynolds]

Thanks all, really appreciate your help on this one. Yup I'm a teacher, but it's not often that I have to calculate volumes -n- stuff, cuz I teach cnc machining/programming.

Thanks again!!

Mike R.

[Simtech]

Michael,

Lets clarify terms to start with:

Mass density: defined as the mass of the substance per unit volume (water=1000kg/m^3)

Specific weight: defined as the weight per unit volume (water=9.81 x 10^3 N/m^3)

Relative density: defined as the ratio of the mass density of a substance to some standard mass density. For solids and liquids, the standard mass density chosen is the maximum density of water. So the relative density of water is 1.0, oil is 0.9, etc ...

In your specific case, you would need the mass density of water (1000kg/m^3) and multiple by the volume of your bottle (in m^3) to obtain the mass of water (kg).

If you convert the 1000kg/m^3 into imperial units, you will get 2204.6226lb/61020in^3 which reduced gives us .036129 lb/in^3.

We could then go on to examine the difference between weight and mass and the imperial and international ways of calculating them ... but thats another thread!

Luc

[gstephens]

Slugs anyone?

P.S. If you don't understand, don't worry about it. This is meant for those VERY FEW who will.

 

[Allan Brown]

Right - 'Weight' is actually the force caused by an object's mass times acceleration (due to gravity on Earth). Imperials pounds are a unit of force (or 'weight'). A slug is the unit of mass that helps to correct an earlier oversight (that gravity is not constant throughout the universe).

A Kilogram is to a Newton as a slug is to a pound.

While a Newton is a Kg*m/sec^2, a pound is a slug*ft/sec^2.

[This message has been edited by Dave Thomson (edited 07-10-2001).]